October 07, 2006
Using AJAX based 3rd party controls in ASP.NET1.1
Recently i was working on one of the project which has developed AJAX based style by using RAD controls developed by telerik. Telerik RadDataGrid control using the AJAX based Client to Server interaction without refresh the page.But the problem we faced when we were using the ASp.net controls like dropdownlist or list control on the same page which already added the Rad contorls, page is refreshing, due to that whole page is reloading again due to normal asp.net web control autopostback = true.
Becuase of page refresh, it's taking long time to reload and effecting the application performace, so to increase the performance of the application and to avoid page reloads, we removed all the Telerik Rad controls and normal asp.net web controls, instead of that we used the PowerWeb LIve Controls which provides the same AJAX based client interaction with out page refreshes.. It's amazing and easy to use PowerWebLIve controls.
No Need to change any code written in aspx.vb file, what we have to change the control declaration definition..that's it. You can do wonders using Power Web Live controls..It's really amazing stuff.
Freshers - Infosys- Test #7
An escalator is descending at constant speed. A walks down and takes 50 steps to reach the bottom. B runs down and takes 90 steps in the same time as A takes 10 steps.How many steps are visible when the escalator is not operating?
Ans: 150 steps
Every day a cyclist meets a train at a particular crossing. The road is straight before the crossing and both are traveling in the same direction. The cyclist travels with a speed of 10 Kmph.
One day the cyclist comes late by 25 min. and meets the train 5km before the crossing.
What is the speed of the train?
Ans: 60 kmph
There are five persons with surnames Mukherjee, Misra, Iyer, Patil and Sharma. There are 4 persons having first or middle name of Kumar, 3 persons with Mohan, 2 persons with Dev and 1 Anil. Either Mukherjee and Patil have a first or middle name of Dev or Misra and Iyer have their first or middle name of Dev. Of Mukherkjee and Misra, either both of them have a first or middle name of Mohan or neither have a first or middle name of Mohan. Either Iyer or Sharma has a first or middle name of Kumar but not both. Who has the first or middle name of Anil?
Ans: Kumar Misra Dev
Mohan Iyer Dev
Kumar Patil Mohan
Mohan Sharma Kumar
Boys are allowed to watch football at C.V.Raman auditorium subjected to conditions.
The boy over age 16 can wear overcoat
No boy over age 15 can wear cap
To watch the football either he has to wear overcoat or cap or both
A boy with an umbrella or above 16 or both cannot wear sweater.
Boys must either not watch football or wear sweater.
What is the appearance of the boy who is watching football?
Solution to be figured out.
A bird keeper has got P pigeons, M mynas and S sparrows. The keeper goes for lunch leaving his assistant to watch the birds. Suppose p=10, m=5, s=8 when the bird keeper comes back, the assistant informs the x birds have escaped. The bird keeper exclaims: "Oh no!
All my sparrows are gone." How many birds flew away?
When the bird keeper comes back, the assistant told him that x birds
have escaped. The keeper realized that at least 2 sparrows have escaped.
What is minimum no of birds that can escape?
Answer the following questions based on the conditions from the choices
A, B, C, D, E as described below:
(A) if a definete conclusion can be drawn from condition 1
(B) if a definete conclusion can be drawn from condition 2
(C) if a definete conclusion can be drawn from condition 1 and 2
(D) if a definete conclusion can be drawn from condition 1 or 2
(E) no conclusion can be drawn using both conditions
person 1 says N<5>5
person 3 says 3N>20
person 4 says 3N>10
person 5 says N<8
What is the value of N?
a) 1. No of persons who speak false being less than no of persons who tells
the truth.
2. Person 2 is telling the truth.
b) 1. no of persong telling the truth is greater than no of persons telling
lies
2. person 5 is telling the truth.
There are N coins on a table and there are two players A & B. You can take 1 or 2 coins at a time. The person who takes the last coin is the loser.
A always starts first.
If N=7
(a) A can always win by taking two coins in his first chance
(b) B can win only if A takes two coins in his first chance.
(c) B can always win by proper play
(d) none of the above
2. A can win by proper play if N is equal to
(a) 13 (b) 37 (c) 22 (d) 34 (e) 48
Ans: (e.)
3. B can win by proper play if N is equal to
(a) 25 (b)26 (c) 32 (d) 41 (e) none
4. if N<4, can A win by proper play always?
(a) Yes (b) No
Two twins have vertain peculiar characteristics. One of them always lies on Monday, Wednesday, Friday. The other always lies on Tuesdays, Thursdays and Saturdays.
On the other days they tell the truth. You are given a conversation.
Person A-- today is Sunday my name is Anil
Person B -- today is Tuesday, my name is Bill
What day is today?
Ans: Today is Tuesday.
There is a safe with a 5 digit number as the key. The 4th digit is 4 greater than second digit, while 3rd digit is 3 less than 2nd digit.The 1st digit is thrice the last digit. There are 3 pairs whose sum is 11. Find the number?
Ans: 65292
A hotel has two wings, the east wing and the west wing. Some east wing rooms but not all have an ocean view. All west wing rooms have a harbor view. The charge for all rooms is identical, except as follows :
Extra charge for all harbor view rooms on or above the 3rd floor
Extra charge for all ocean view rooms except those without balcony
Extra charge for some harbor rooms on the first two floor & some east
wing rooms without ocean view but having kitchen facilities.
Which of the following cannot be determined on the basis of the
information given:
I. Whether there are any rooms without a balcony for which an extra charge
is imposed.
II. Whether any room without a kitchen or a view involves an extra charge.
III. Whether two extra charges are impsed for any room.
(A) I only
(B) II only
(C) III only
(D) II and III only
(E) I, II and III
(This question is from 1999 Barron's GRE Guide model Test 3 - section 6,
question 22)
Ans: (A)
Freshers - Infosys- Test #6
From a vessel, 1/3rd of the liquid evaporates on the first day. On the second day 3/4th of the remaining liquid evaporates. What fraction of the volume is present at the end of the second day?Ans: 50%
An orange glass has orange juice and white glass has apple juice both of equal volumes.
50ml of the orange juice is taken and poured into the apple juice.50ml from the white glass is poured into the orange glass. Of the two quantities, the amount of apple juice in the orange glass and the amount of orange juice in the white glass, which one is greater and by how much?
Ans: The two quantities are equal
There is a 4 inch cube painted on all sides. This is cut down into of 1 inch cubes. What is the no of cubes which have no pointed sides?
Ans: 8
Sam and Mala have a conversation.
Sam says I am certainly not over 40
Mala says I am 38 and you are at least 5 years older than me
Now Sam says you are at least 39
All the statements by the two are false.How old are they really?
Ans: Mala = 38 yrs
Sam = 41 yrs.
Ram Singh goes to his office in the city, every day from his suburban house.
His driver Gangaram drops him at the railway station in the morning and
picks him up in the evening. Every evening Ram Singh reaches the station at 5 O' Clock.
Gangaram also reaches at the same time. One day Ram Singh started early from his office and came to the station at 4 O' Clock. Not wanting to wait for the car he starts walking home.
Mangaram starts at normal time, picks him up on the way and takes him back
house, half an hour early.
How much time did Ram Singh walk?
In a railway station, there are two trains going. One in the harbour line and one in the main line, each having a frequency of 10 minutes. The main line service starts at 5 o'clock and the harbor line starts at 5.02A.M.
A man goes to the station every day to catch the first train that comes.
What is the probability of the man catching the first train?
Ans: 0.8
A family X went for a vacation. Unfortunately it rained for 13 days when they were there.
But whenever it rained in the mornings, they had clear afternoons and vice versa.
In all they enjoyed 11 mornings and 12 afternoons. How many days did they stay there totally?
Ans: 18
Freshers - Infosys- Test #5
A man collects cigarette stubs and makes one full cigarette with every 8 stubs. If he gets 64 stubs how many full cigarettes can he smoke.Ans: 8+1=9
A soldier looses his way in a thick jungle. At random he walks from his camp but mathematically in an interesting fashion. First he walks one mile East then half mile to North. Then 1/4 mile to West, then 1/8 mile to South and so on making a loop. Finally how far he is from his camp and in which direction?
Ans: Distance travelled in north and south directions
1/2 - 1/8 + 1/32 - 1/128 + 1/512 - and so on
= 1/2/((1-(-1/4))
Similarly in east and west directions
1- 1/4 + 1/16 - 1/64 + 1/256 - and so on
= 1/(( 1- ( - 1/4))
Add both the answers
How can 1000000000 be written as a product of two factors neither of them containing zeros
Ans: 2 power 9 x 5 power 9
Conversation between two mathematicians:
First : I have three children. The product of their ages is 36. If you sum their ages, it is exactly same as my neighbor's door number on my left. The second mathematician verifies the door number and says that it is not sufficient.
Then the first says " Ok one more clue is that my youngest is really the youngest". Immediately the second mathematician answers .
Can you answer the question asked by the first mathematician?
What are the children ages?
Ans 1,6 and 6
Light glows for every 13 seconds . How many times did it glow between 1:57:58 and 3:20:47 am.
Ans : 383 + 1 = 384
500 men are arranged in an array of 10 rows and 50 columns according to their heights.
Tallest among each row of all are asked to fall out. And the shortest among them is A. Similarly after resuming that to their original positions that the shortest among each column are asked to fall out. And the tallest among them is B. Now who is taller among A and B ?
Ans A
A person with some money spends1/3 for cloths, 1/5 of the remaining for food and 1/4 of the remaining for travel. He is left with Rs 100/- . How much did he have with him in the beginning ?
Ans: Rs 250/-
There are six boxes containing 5 , 7 , 14 , 16 , 18 , 29 balls of either red or blue in color.
Some boxes contain only red balls and others contain only blue. One sales man sold one box out of them and then he says " I have the same number of red balls left out as that of blue ".
Which box is the one he solds out ?
Ans: Total no of balls = 89 and (89-29 /2) = 60/2 = 30 and
also 14 + 16 = 5 + 7 + 18 = 30
A chain is broken into three pieces of equal lenths containing 3 links each. It is taken to a backsmith to join into a single continuous one . How many links are to to be opened to make it ?
Ans : 2.
Grass in lawn grows equally thick and in a uniform rate. It takes 24 days for 70 cows and 60 days for 30 cows to eat the whole of the grass. How many cows are needed to eat the grass in 96 days.?
Ans : 20
g - grass at the beginning
r - rate at which grass grows, per day
y - rate at which one cow eats grass, per day
n - no of cows to eat the grass in 96 days
g + 24*r = 70 * 24 * y
g + 60*r = 30 * 60 * y
g + 96*r = n * 96 * y
Solving, n = 20.
(5 marks)
Freshers - Infosys- Test #4
Ann, Booby, Cathy and Dave are at their monthly business meeting. Their occupations are author, biologist, chemist and doctor, but not necessarily in that order. Dave just told the biologist that Cathy was on her way with doughnuts. Ann is sitting across from the doctor and next to the chemist. The doctor was thinking that Booby was a goofy name for parent's tochoose, but didn't say anything. What is each person's occupation?
Ans: Since Dave spoke to the biologist and Ann sat next to the chemist and
across the doctor, Cathy must be the author and Ann the biologist.
The doctor didn't speak, but David did, so Bobbie is the doctor and
Dave the chemist.
Sometime after 10:00 PM a murder took place. A witness claimed that the clock must have stopped at the time of the shooting. It was later found that the position of both the hands
were the same but their positions had interchanged. Tell the time of the shooting (both actual and claimed).
Ans: Time of shooting = 11:54 PM
Claimed Time = 10:59 PM
Next number in the series is
1 , 2 , 4 , 13 , 31 , 112 , ?
Ans: 224.
No number has digits more than 4. All of them are 1 , 2, 4, 8 ,16 ,
32 , 64 converted to numbers in base 5
Shahrukh speaks truth only in the morning and lies in the afternoon, whereas Salman speaks truth only in the afternoon. A says that B is Shahrukh. Is it morning or afternoon and who is A-Shahrukh or Salman.
Ans: Afternoon ; A is Salman.
Two trains starting at same time, one from Bangalore to Mysore and other in opposite direction arrive at their destination 1 hr and 4 hours respectively after passing each other. How much faster is one train from other?
Ans: Twice
There are 6 volumes of books on a rack kept in order ( ie vol.1, vol. 2 and so on ). Give the position after the following changes were noticed.
All books have been changed
Vol.5 was directly to the right of Vol.2
Vol.4 has Vol.6 to its left and both weren't at Vol.3's place
Vol.1 has Vol.3 on right and Vol.5 on left
An even numbered volume is at Vol.5's place
Find the order in which the books are kept now?
Ans: 2 , 5 , 1 , 3 , 6 , 4
I bought a car with a peculiar 5 digit numbered license plate which on reversing could still be read. On reversing value is increased by 78633.Whats the original number if all digits were different?
Ans: Only 0 1 6 8 and 9 can be readupside down.So on rearranging these
digits we get the answer as 10968
The shape in the sketch below is that of a square attached to half of a similar square. Divide it into four equal pieces
Ans: Hint : the figure can be divided into 12 equal triangles
Supposing a clock takes 7 seconds to strike 7. How mlong will it take to strike 10?
Ans: 10 1/2 seconds.
Freshers - Infosys- Test #3
Fifty minutes ago if it was four times as many minutes past three o'clock, how many minutes is it to six o'clock?Ans: Twenty six minutes.
If a clock takes 7seconds to strike 7, how long will the same clock take to strike 10?
Ans: The clock strikes for the first time at the start and takes 7 seconds
for 6 intervals-thus for one interval time taken=7/6.
Therefore, for 10 seconds there are 9 intervals and time taken is
9*7/6=10 and 1/2 seconds.
Three criminals were arrested for shop lifting. However, when interrogated only one told the truth in both his statements, while the other two each told one true statement and one lie.
The statements were:
ALBERT :(a)Chander passed the merchandise.(b)Bruce created the diversion.
BRUCE :(a)Albert passed the merchandise. (b)I created the diversion.
CLIVE :(a)I took the goods out of the shop. (b)Bruce passed them over.
Ans: Albert passed the goods.Bruce created the diversion. Clive took the
goods out of the shop.
Everyday in his business a merchant had to weigh amounts from 1 kg to 121 kgs, to the nearest kg.What are the minimum number of weight required and \ how heavy should they be?
Ans: .The minimum number is 5 and they should weigh 1,3,9,27 and 81 kgs.
A hotel has 10 storeys.Which floor is above the floor below the floor, below the floor above the floor, below the floor above the fifth.
Ans: The sixth floor.
Seven members sat around a table for three days for a conference. The member's names were Abhishek, Amol, Ankur, Anurag,Bhuwan ,Vasu and Vikram. The meetings were chaired by Vikram. On the first evening members sat around the table alphabetically. On the following two nights, Vikram arranged the seatings so that he could have Abhishek as near to him as possible and abesent minded Vasu as far away as he could. On no evening did any person have sitting next to him a person who had previously been his neighbour.
How did Vikram manage to seat everybody to the best advantage on the
second and third evenings?
Ans: Second evening:Vikram,Ankur,Abhishek,Amol,Vasu,Anurag and Bhuwan.
Third evening :Vikram,Anurag,Abhishek,Vasu,Bhuwan,Ankur,Amol.
Two trains start from stations A and B spaced 50 kms apart at the same time and speed. As the trains start, a bird flies from one train towards the other and on reaching the second train, it flies back to the first train. This is repeated till the trains collide. If the speed of the trains is 25 km/h and that of the bird is 100km/h. How much did the bird travel till the collision?
Ans: 100 kms.
Four prisoners escape from a prison. The prisoners, Mr East, Mr West, Mr South, Mr North head towards different directions after escaping. The following information of their escape
was supplied: The escape routes were The North Road, South Road, East Road and West Road.
None of the prisoners took the road which was their namesake. Mr.East did not take the South Road Mr.West did not the South Road. The West Road was not taken by Mr.East
What road did each of the prisoners take to make their escape?
Ans: Mr.East took the North Road
Mr.West took the East Road
Mr.North took the South Road
Mr.South took the West Road.
10. Complete the series:
5, 20, 24, 6, 2, 8, ?
Ans: 12 (as 5*4=20, 20+4=24, 24/4=6, 6-4=2, 2*4=8, 8+4=12).
Freshers - Infosys- Test #2
At 6'o a clock ticks 6 times. The time between first and last ticks is 30 seconds.How long does it tick at 12'o clock?
Ans: 66 sec. (2 marks)
Three friends divided some bullets equally. After all of them shot 4 bullets the total number of bullets remaining is equal to the bullets each had after division. Find the original number divided?
Ans: 18 (2 marks)
Initially . x x x
Now x-4 x-4 x-4
Equation is 3x-12 = x
A ship went on a voyage. After it had traveled 180 miles a plane started with 10 times the
speed of the ship. Find the distance when they meet from starting point.
Ans: 200miles. (2 marks)
Distance travelled by plane = 1/10 distance travelled by ship +
180
There are 3 societies A, B, C. A lent cars to B and C as many as they had already. After some time B gave as many tractors to A and C as many as they have. After sometime c did the same thing. At the end of this transaction each one of them had 24.Find the cars each originally had?
Ans: A had 39 cars, B had 21 cars & C had 12 cars (4 marks)
There N stations on a railroad. After adding X stations on the rail route 46 additional tickets have to be printed. Find N and X?
Ans. x=2 and N=11
Let initially, N(N-1) = t
After adding, (N+X)(N+X-1) = t+46
By trail and error method (4 marks)
Given that April 1 is Tuesday. A, B, C are 3 persons told that their farewell party was on
A - May 8, Thursday
B - May 10,tuesday
C - June 5, friday
Out of A, B, C only one made a completely true statement concerning date, day and month
The other told two one told the day right and the other the date right..
What is correct date, month, day.
Ans: B - (May 10) SUNDAY
C - June 6 (Friday). (5 marks)
The Bulls, Pacers, Lakers and Jazz ran for a contest. Anup, Sujit, John made the following statements regarding results.
Anup said either Bulls or Jazz will definitely win
Sujit said he is confident that Bulls will not win
John said he is confident that neither Jazz nor Lakers will win
When the result cameit was found that only one of the above three had
made a correct statement.
Who has made the correct statement and who has won the contest.
Ans: Sujith; Lakers (5marks )
Five people A ,B ,C ,D ,E are related to each other. Four of them make one true statement each as follows.
(i) B is my father's brother.
(ii) E is my mother-in-law.
(iii)C is my son-in-law's brother
(iv)A is my brother's wife.
Ans: (i) D
(ii) B
(iii) E
(iv) C (10 marks)
Some statements are given below:
L says all of my other four friends have money
M says that P said that exactly one among them has money
N says that L said that precisely two among them have money
O says that M said that three of the others have money
P, L and N said that they have money
All the above statement are false..
Who has money & who doesn't have any money?
(5 marks)
Freshers - Infosys- Test #1
Father's age is three years more than three times the son's age. After three years, father's age will be ten years more than twice the son's age. What is the father's present age?Ans: 33 years. (2 marks)
Find the values of each of the alphabets.
N O O N
S O O N
+ M O O N
----------
J U N E
Ans: 9326 (2 marks)
There are 20 poles with a constant distance between each pole A car takes 24 second to reach the 12th pole. How much will it take to reach the last pole?
Ans: 41.45 seconds (2 marks)
Let the distance between two poles = x
Hence 11x:24::19x:?
A car is traveling at a uniform speed. The driver sees a milestone showing a 2-digit number.
After traveling for an hour the driver sees another milestone with the same digits in reverse order. After another hour the driver sees another milestone containing the same two digits. What is the average speed of the driver?
Ans: 45 kmph (4 marks)
The minute and the hour hand of a watch meet every 65 minutes. How much does the watch lose or gain time and by how much?
Ans: Gains; 5/11 minutes (4 marks)
Ram, Sham and Gunman are friends. Ram is a widower and lives alone and his sister takes care of him. Sham is a bachelor and his niece cooks his food and looks after his house. Gunman is married to Gita and lives in large house in the same town. Gita gives the idea that all of them could stay together in the house and share monthly expenses equally. During their first month of living together, each person contributed Rs.25. At the end of the month, it was found that Rs 92 was the expense so the remaining amount was distributed equally among everyone. The distribution was such that everyone received a whole number of Rupees. How much did each person receive?
Ans. Rs 2 (4 marks)
(Hint: Ram's sister, Sham's niece and Gunman's wife are the
same
person)
Four persons A, B, C and D are playing cards. Each person has one card, laid down on the table below him, which has two different colors on either side. The colors visible on the table are Red, Green, Red and Blue. They see the color on the reverse side and give the following comment.
A: Yellow or Green
B: Neither Blue nor Green
C: Blue or Yellow
D: Blue or Yellow
Given that out of the 4 people 2 always lie find out the colors on the
cards each person.
(5 marks)
ASP.NET FAQ Eight
What's the advantage of using System.Text.StringBuilder over System.String?StringBuilder is more efficient in the cases, where a lot of manipulation is done to the text. Strings are immutable, so each time it's being operated on, a new instance is created.
Can you store multiple data types in System.Array?
No.
What's the difference between the System.Array.CopyTo() and System.Array.Clone()?
The first one performs a deep copy of the array, the second one is shallow.
How can you sort the elements of the array in descending order?
By calling Sort() and then Reverse() methods.
What's the .NET datatype that allows the retrieval of data by a unique key?
HashTable.
What's class SortedList underneath?
A sorted HashTable.
Will finally block get executed if the exception had not occurred?
Yes.
What's the C# equivalent of C++ catch (. . .), which was a catch-all statement for any possible exception?
A catch block that catches the exception of type System.Exception. You can also omit the parameter data type in this case and just write catch {}.
Can multiple catch blocks be executed?
No, once the proper catch code fires off, the control is transferred to the finally block (if there are any), and then whatever follows the finally block.
Why is it a bad idea to throw your own exceptions?
Well, if at that point you know that an error has occurred, then why not write the proper code to handle that error instead of passing a new Exception object to the catch block? Throwing your own exceptions signifies some design flaws in the project.
What's a delegate?
A delegate object encapsulates a reference to a method. In C++ they were referred to as function pointers.
What's a multicast delegate?
It's a delegate that points to and eventually fires off several methods.
How's the DLL Hell problem solved in .NET?
Assembly versioning allows the application to specify not only the library it needs to run (which was available under Win32), but also the version of the assembly.
What are the ways to deploy an assembly?
An MSI installer, a CAB archive, and XCOPY command.
What's a satellite assembly?
When you write a multilingual or multi-cultural application in .NET, and want to distribute the core application separately from the localized modules, the localized assemblies that modify the core application are called satellite assemblies.
What namespaces are necessary to create a localized application?
System.Globalization, System.Resources.
What's the difference between // comments, /* */ comments and /// comments?
Single-line, multi-line and XML documentation comments.
How do you generate documentation from the C# file commented properly with a command-line compiler?
Compile it with a /doc switch.
What's the difference between
XML documentation tag? Single line code example and multiple-line code example.
Is XML case-sensitive?
Yes, so Student and student are different elements.
What debugging tools come with the .NET SDK?
CorDBG – command-line debugger, and DbgCLR – graphic debugger. Visual Studio .NET uses the DbgCLR. To use CorDbg, you must compile the original C# file using the /debug switch.
What does the This window show in the debugger?
It points to the object that's pointed to by this reference. Object's instance data is shown.
What does assert() do?
In debug compilation, assert takes in a Boolean condition as a parameter, and shows the error dialog if the condition is false. The program proceeds without any interruption if the condition is true.
What's the difference between the Debug class and Trace class?
Documentation looks the same. Use Debug class for debug builds, use Trace class for both debug and release builds.
Why are there five tracing levels in System.Diagnostics.TraceSwitcher?
The tracing dumps can be quite verbose and for some applications that are constantly running you run the risk of overloading the machine and the hard drive there. Five levels range from None to Verbose, allowing to fine-tune the tracing activities.
Where is the output of TextWriterTraceListener redirected?
To the Console or a text file depending on the parameter passed to the constructor.
How do you debug an ASP.NET Web application?
Attach the aspnet_wp.exe process to the DbgClr debugger.
What are three test cases you should go through in unit testing?
Positive test cases (correct data, correct output), negative test cases (broken or missing data, proper handling), exception test cases (exceptions are thrown and caught properly).
Can you change the value of a variable while debugging a C# application?
Yes, if you are debugging via Visual Studio.NET, just go to Immediate window.
Explain the three services model (three-tier application).
Presentation (UI), business (logic and underlying code) and data (from storage or other sources).
What are advantages and disadvantages of Microsoft-provided data provider classes in ADO.NET?
SQLServer.NET data provider is high-speed and robust, but requires SQL Server license purchased from Microsoft. OLE-DB.NET is universal for accessing other sources, like Oracle, DB2, Microsoft Access and Informix, but it's a .NET layer on top of OLE layer, so not the fastest thing in the world. ODBC.NET is a deprecated layer provided for backward compatibility to ODBC engines.
What's the role of the DataReader class in ADO.NET connections?
It returns a read-only dataset from the data source when the command is executed.
What is the wildcard character in SQL?
Let's say you want to query database with LIKE for all employees whose name starts with La. The wildcard character is %, the proper query with LIKE would involve 'La%'.
Explain ACID rule of thumb for transactions.
Transaction must be Atomic (it is one unit of work and does not dependent on previous and following transactions), Consistent (data is either committed or roll back, no "in-between" case where something has been updated and something hasn't), Isolated (no transaction sees the intermediate results of the current transaction), Durable (the values persist if the data had been committed even if the system crashes right after).
What connections does Microsoft SQL Server support?
Windows Authentication (via Active Directory) and SQL Server authentication (via Microsoft SQL Server username and passwords).
Which one is trusted and which one is untrusted?
Windows Authentication is trusted because the username and password are checked with the Active Directory, the SQL Server authentication is untrusted, since SQL Server is the only verifier participating in the transaction.
Why would you use untrusted verificaion?
Web Services might use it, as well as non-Windows applications.
What does the parameter Initial Catalog define inside Connection String?
The database name to connect to.
What's the data provider name to connect to Access database?
Microsoft.Access.
What does Dispose method do with the connection object?
Deletes it from the memory.
What is a pre-requisite for connection pooling?
Multiple processes must agree that they will share the same connection, where every parameter is the same, including the security settings.
ASP.NET FAQ Seven
What's the implicit name of the parameter that gets passed into the class' set method?Value, and its datatype depends on whatever variable we're changing.
How do you inherit from a class in C#?
Place a colon and then the name of the base class. Notice that it's double colon in C++.
Does C# support multiple inheritance?
No, use interfaces instead.
When you inherit a protected class-level variable, who is it available to?
Classes in the same namespace.
Are private class-level variables inherited?
Yes, but they are not accessible, so looking at it you can honestly say that they are not inherited. But they are.
Describe the accessibility modifier protected internal.
It's available to derived classes and classes within the same Assembly (and naturally from the base class it's declared in).
C# provides a default constructor for me. I write a constructor that takes a string as a parameter, but want to keep the no parameter one. How many constructors should I write?
Two. Once you write at least one constructor, C# cancels the freebie constructor, and now you have to write one yourself, even if there's no implementation in it.
What's the top .NET class that everything is derived from?
System.Object.
How's method overriding different from overloading?
When overriding, you change the method behavior for a derived class. Overloading simply involves having a method with the same name within the class.
What does the keyword virtual mean in the method definition?
The method can be over-ridden.
Can you declare the override method static while the original method is non-static?
No, you can't, the signature of the virtual method must remain the same, only the keyword virtual is changed to keyword override.
Can you override private virtual methods?
No, moreover, you cannot access private methods in inherited classes, have to be protected in the base class to allow any sort of access.
Can you prevent your class from being inherited and becoming a base class for some other classes?
Yes, that's what keyword sealed in the class definition is for. The developer trying to derive from your class will get a message: cannot inherit from Sealed class WhateverBaseClassName. It's the same concept as final class in Java.
Can you allow class to be inherited, but prevent the method from being over-ridden?
Yes, just leave the class public and make the method sealed.
What's an abstract class?
A class that cannot be instantiated. A concept in C++ known as pure virtual method. A class that must be inherited and have the methods over-ridden. Essentially, it's a blueprint for a class without any implementation.
When do you absolutely have to declare a class as abstract (as opposed to free-willed educated choice or decision based on UML diagram)?
When at least one of the methods in the class is abstract. When the class itself is inherited from an abstract class, but not all base abstract methods have been over-ridden.
What's an interface class?
It's an abstract class with public abstract methods all of which must be implemented in the inherited classes.
Why can't you specify the accessibility modifier for methods inside the interface?
They all must be public. Therefore, to prevent you from getting the false impression that you have any freedom of choice, you are not allowed to specify any accessibility, it's public by default.
Can you inherit multiple interfaces?
Yes.
And if they have conflicting method names?
It's up to you to implement the method inside your own class, so implementation is left entirely up to you. This might cause a problem on a higher-level scale if similarly named methods from different interfaces expect different data, but as far as compiler cares you're okay.
What's the difference between an interface and abstract class?
In the interface all methods must be abstract; in the abstract class some methods can be concrete. In the interface no accessibility modifiers are allowed, which is ok in abstract classes.
How can you overload a method?
Different parameter data types, different number of parameters, different order of parameters.
If a base class has a bunch of overloaded constructors, and an inherited class has another bunch of overloaded constructors, can you enforce a call from an inherited constructor to an arbitrary base constructor?
Yes, just place a colon, and then keyword base (parameter list to invoke the appropriate constructor) in the overloaded constructor definition inside the inherited class.
What's the difference between System.String and System.StringBuilder classes?
System.String is immutable; System.StringBuilder was designed with the purpose of having a mutable string where a variety of operations can be performed.
What's the advantage of using System.Text.StringBuilder over System.String?
StringBuilder is more efficient in the cases, where a lot of manipulation is done to the text. Strings are immutable, so each time it's being operated on, a new instance is created.
Can you store multiple data types in System.Array?
No.
What's the difference between the System.Array.CopyTo() and System.Array.Clone()?
The first one performs a deep copy of the array, the second one is shallow.
How can you sort the elements of the array in descending order?
By calling Sort() and then Reverse() methods.
What's the .NET datatype that allows the retrieval of data by a unique key?
HashTable.
What's class SortedList underneath?
A sorted HashTable.
Will finally block get executed if the exception had not occurred?
Yes.
What's the C# equivalent of C++ catch (...), which was a catch-all statement for any possible exception?
A catch block that catches the exception of type System.Exception. You can also omit the parameter data type in this case and just write catch {}.
Can multiple catch blocks be executed?
No, once the proper catch code fires off, the control is transferred to the finally block (if there are any), and then whatever follows the finally block.
Why is it a bad idea to throw your own exceptions?
Well, if at that point you know that an error has occurred, then why not write the proper code to handle that error instead of passing a new Exception object to the catch block? Throwing your own exceptions signifies some design flaws in the project.
What's a delegate?
A delegate object encapsulates a reference to a method. In C++ they were referred to as function pointers.
What's a multicast delegate?
It's a delegate that points to and eventually fires off several methods.
How's the DLL Hell problem solved in .NET?
Assembly versioning allows the application to specify not only the library it needs to run (which was available under Win32), but also the version of the assembly.
What are the ways to deploy an assembly?
An MSI installer, a CAB archive, and XCOPY command.
What's a satellite assembly?
When you write a multilingual or multi-cultural application in .NET, and want to distribute the core application separately from the localized modules, the localized assemblies that modify the core application are called satellite assemblies.
What namespaces are necessary to create a localized application?
System.Globalization, System.Resources.
ASP.NET FAQ Six
What is the difference between repeater over datalist and datagrid?The Repeater class is not derived from the WebControl class, like the DataGrid and DataList. Therefore, the Repeater lacks the stylistic properties common to both the DataGrid and DataList. What this boils down to is that if you want to format the data displayed in the Repeater, you must do so in the HTML markup.
The Repeater control provides the maximum amount of flexibility over the HTML produced. Whereas the DataGrid wraps the DataSource contents in an HTML <>, and the DataList wraps the contents in either an HTML <> or <> tags (depending on the DataList's RepeatLayout property), the Repeater adds absolutely no HTML content other than what you explicitly specify in the templates.
While using Repeater control, If we wanted to display the employee names in a bold font we'd have to alter the "ItemTemplate" to include an HTML bold tag, Whereas with the DataGrid or DataList, we could have made the text appear in a bold font by setting the control's ItemStyle-Font-Bold property to True.
The Repeater's lack of stylistic properties can drastically add to the development time metric. For example, imagine that you decide to use the Repeater to display data that needs to be bold, centered, and displayed in a particular font-face with a particular background color. While all this can be specified using a few HTML tags, these tags will quickly clutter the Repeater's templates. Such clutter makes it much harder to change the look at a later date. Along with its increased development time, the Repeater also lacks any built-in functionality to assist in supporting paging, editing, or editing of data. Due to this lack of feature-support, the Repeater scores poorly on the usability scale.
However, The Repeater's performance is slightly better than that of the DataList's, and is more noticeably better than that of the DataGrid's. Following figure shows the number of requests per second the Repeater could handle versus the DataGrid and DataList
Can we handle the error and redirect to some pages using web.config?
Yes, we can do this, but to handle errors, we must know the error codes; only then we can take the user to a proper error message page, else it may confuse the user.
CustomErrors Configuration section in web.config file:
The default configuration is:
< mode="RemoteOnly" defaultredirect="Customerror.aspx">
< statuscode="404" redirect="Notfound.aspx">
< /customErrors >
If mode is set to Off, custom error messages will be disabled. Users will receive detailed exception error messages.
If mode is set to On, custom error messages will be enabled.
If mode is set to RemoteOnly, then users will receive custom errors, but users accessing the site locally will receive detailed error messages.
Add an <> tag for each error you want to handle. The error tag will redirect the user to the Notfound.aspx page when the site returns the 404 (Page not found) error.
[Example]
There is a page MainForm.aspx
Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
'Put user code to initialize the page here
Dim str As System.Text.StringBuilder
str.Append("hi") ' Error Line as str is not instantiated
Response.Write(str.ToString)
End Sub
[Web.Config]
< mode="On" defaultredirect="Error.aspx">
' a simple redirect will take the user to Error.aspx [user defined] error file.
< mode="RemoteOnly" defaultredirect="Customerror.aspx">
< statuscode="404" redirect="Notfound.aspx">
< /customErrors >
'This will take the user to NotFound.aspx defined in IIS.
How do you implement Paging in .Net?
The DataGrid provides the means to display a group of records from the data source (for example, the first 10), and then navigate to the "page" containing the next 10 records, and so on through the data.
Using Ado.Net we can explicit control over the number of records returned from the data source, as well as how much data is to be cached locally in the DataSet.
1.Using DataAdapter.fill method give the value of 'Maxrecords' parameter
(Note: - Don't use it because query will return all records but fill the dataset based on value of 'maxrecords' parameter).
2.For SQL server database, combines a WHERE clause and a ORDER BY clause with TOP predicate.
3.If Data does not change often just cache records locally in DataSet and just take some records from the DataSet to display.
What is the difference between Server.Transfer and Response.Redirect?
Server.Transfer() : client is shown as it is on the requesting page only, but the all the content is of the requested page. Data can be persist across the pages using Context.Item collection, which is one of the best way to transfer data from one page to another keeping the page state alive.
Response.Dedirect() :client knows the physical location (page name and query string as well). Context.Items loses the persistence when navigate to destination page. In earlier versions of IIS, if we wanted to send a user to a new Web page, the only option we had was Response.Redirect. While this method does accomplish our goal, it has several important drawbacks. The biggest problem is that this method causes each page to be treated as a separate transaction. Besides making it difficult to maintain your transactional integrity, Response.Redirect introduces some additional headaches. First, it prevents good encapsulation of code. Second, you lose access to all of the properties in the Request object. Sure, there are workarounds, but they're difficult. Finally, Response.Redirect necessitates a round trip to the client, which, on high-volume sites, causes scalability problems. As you might suspect, Server.Transfer fixes all of these problems. It does this by performing the transfer on the server without requiring a roundtrip to the client.
Response.Redirect sends a response to the client browser instructing it to request the second page. This requires a round-trip to the client, and the client initiates the Request for the second page. Server.Transfer transfers the process to the second page without making a round-trip to the client. It also transfers the HttpContext to the second page, enabling the second page access to all the values in the HttpContext of the first page.
Can you create an app domain?
Yes, We can create user app domain by calling on of the following overload static methods of the System.AppDomain class
1. Public static AppDomain CreateDomain(String friendlyName)
2. Public static AppDomain CreateDomain(String friendlyName, Evidence securityInfo)
3. Public static AppDomain CreateDomain(String friendlyName, Evidence securityInfo, AppDomainSetup info)
4. Public static AppDomain CreateDomain(String friendlyName, Evidence securityInfo, String appBasePath, String appRelativeSearchPath, bool shadowCopyFiles)
What are the various security methods which IIS Provides apart from .NET ?
The various security methods which IIS provides are
a) Authentication Modes
b) IP Address and Domain Name Restriction
c) DNS Lookups DNS Lookups
d) The Network ID and Subnet Mask
e) SSL
What is Web Gardening? How would using it affect a design?
The Web Garden Model
The Web garden model is configurable through the section of the machine.config file. Notice that the section is the only configuration section that cannot be placed in an application-specific web.config file. This means that the Web garden mode applies to all applications running on the machine. However, by using the node in the machine.config source, you can adapt machine-wide settings on a per-application basis.
Two attributes in the section affect the Web garden model. They are webGarden and cpuMask. The webGarden attribute takes a Boolean value that indicates whether or not multiple worker processes (one per each affinitized CPU) have to be used. The attribute is set to false by default. The cpuMask attribute stores a DWORD value whose binary representation provides a bit mask for the CPUs that are eligible to run the ASP.NET worker process. The default value is -1 (0xFFFFFF), which means that all available CPUs can be used. The contents of the cpuMask attribute is ignored when the webGarden attribute is false. The cpuMask attribute also sets an upper bound to the number of copies of aspnet_wp.exe that are running.
Web gardening enables multiple worker processes to run at the same time. However, you should note that all processes will have their own copy of application state, in-process session state, ASP.NET cache, static data, and all that is needed to run applications. When the Web garden mode is enabled, the ASP.NET ISAPI launches as many worker processes as there are CPUs, each a full clone of the next (and each affinitized with the corresponding CPU). To balance the workload, incoming requests are partitioned among running processes in a round-robin manner. Worker processes get recycled as in the single processor case. Note that ASP.NET inherits any CPU usage restriction from the operating system and doesn't include any custom semantics for doing this.
All in all, the Web garden model is not necessarily a big win for all applications. The more stateful applications are, the more they risk to pay in terms of real performance. Working data is stored in blocks of shared memory so that any changes entered by a process are immediately visible to others. However, for the time it takes to service a request, working data is copied in the context of the process. Each worker process, therefore, will handle its own copy of working data, and the more stateful the application, the higher the cost in performance. In this context, careful and savvy application benchmarking is an absolute must.
Changes made to the section of the configuration file are effective only after IIS is restarted. In IIS 6, Web gardening parameters are stored in the IIS metabase; the webGarden and cpuMask attributes are ignored.
What is view state?.where it stored?.can we disable it?
The web is state-less protocol, so the page gets instantiated, executed, rendered and then disposed on every round trip to the server. The developers code to add "statefulness" to the page by using Server-side storage for the state or posting the page to itself. When require to persist and read the data in control on webform, developer had to read the values and store them in hidden variable (in the form), which were then used to restore the values. With advent of .NET framework, ASP.NET came up with ViewState mechanism, which tracks the data values of server controls on ASP.NET webform. In effect,ViewState can be viewed as "hidden variable managed by ASP.NET framework!". When ASP.NET page is executed, data values from all server controls on page are collected and encoded as single string, which then assigned to page's hidden atrribute "< type="hidden">", that is part of page sent to the client.
ViewState value is temporarily saved in the client's browser.ViewState can be disabled for a single control, for an entire page orfor an entire web application. The syntax is:
Disable ViewState for control (Datagrid in this example)
< enableviewstate="false">
Disable ViewState for a page, using Page directive
< %@ Page EnableViewState="False" ... % >
Disable ViewState for application through entry in web.config
< enableviewstate="false">
ASP.NET FAQ Five
When you are running a component within ASP.NET, what process is it running within on Windows XP? Windows 2000? Windows 2003?On Windows 2003 (IIS 6.0) running in native mode, the component is running within the w3wp.exe process associated with the application pool which has been configured for the web application containing the component.
On Windows 2003 in IIS 5.0 emulation mode, 2000, or XP, it's running within the IIS helper process whose name I do not remember, it being quite a while since I last used IIS 5.0.
What does aspnet_regiis -i do ?
Aspnet_regiis.exe is The ASP.NET IIS Registration tool allows an administrator or installation program to easily update the script maps for an ASP.NET application to point to the ASP.NET ISAPI version associated with the tool. The tool can also be used to display the status of all installed versions of ASP. NET, register the ASP.NET version coupled with the tool, create client-script directories, and perform other configuration operations.
When multiple versions of the .NET Framework are executing side-by-side on a single computer, the ASP.NET ISAPI version mapped to an ASP.NET application determines which version of the common language runtime is used for the application.
The tool can be launched with a set of optional parameters. Option "i" Installs the version of ASP.NET associated with Aspnet_regiis.exe and updates the script maps at the IIS metabase root and below. Note that only applications that are currently mapped to an earlier version of ASP.NET are affected
What is a PostBack?
The process in which a Web page sends data back to the same page on the server.
What is ViewState? How is it encoded? Is it encrypted? Who uses ViewState?
ViewState is the mechanism ASP.NET uses to keep track of server control state values that don't otherwise post back as part of the HTTP form. ViewState Maintains the UI State of a Page
ViewState is base64-encoded.
It is not encrypted but it can be encrypted by setting EnableViewStatMAC="true" & setting the machineKey validation type to 3DES. If you want to NOT maintain the ViewState, include the directive < %@ Page EnableViewState="false" % > at the top of an .aspx page or add the attribute EnableViewState="false" to any control.
What is the <> element and what two ASP.NET technologies is it used for?
Configures keys to use for encryption and decryption of forms authentication cookie data and view state data, and for verification of out-of-process session state identification.There fore 2 ASP.Net technique in which it is used are Encryption/Decryption & Verification
What three Session State providers are available in ASP.NET 1.1? What are the pros and cons of each?
ASP.NET provides three distinct ways to store session data for your application: in-process session state, out-of-process session state as a Windows service, and out-of-process session state in a SQL Server database. Each has it advantages.
1.In-process session-state mode
Limitations:
* When using the in-process session-state mode, session-state data is lost if aspnet_wp.exe or the application domain restarts.
* If you enable Web garden mode in the <> element of the application's Web.config file, do not use in-process session-state mode. Otherwise, random data loss can occur.
Advantage:
* in-process session state is by far the fastest solution. If you are storing only small amounts of volatile data in session state, it is recommended that you use the in-process provider.
2. The State Server simply stores session state in memory when in out-of-proc mode. In this mode the worker process talks directly to the State Server
3. SQL mode, session states are stored in a SQL Server database and the worker process talks directly to SQL. The ASP.NET worker processes are then able to take advantage of this simple storage service by serializing and saving (using .NET serialization services) all objects within a client's Session collection at the end of each Web request
Both these out-of-process solutions are useful primarily if you scale your application across multiple processors or multiple computers, or where data cannot be lost if a server or process is restarted.
What is the difference between HTTP-Post and HTTP-Get?
As their names imply, both HTTP GET and HTTP POST use HTTP as their underlying protocol. Both of these methods encode request parameters as name/value pairs in the HTTP request.
The GET method creates a query string and appends it to the script's URL on the server that handles the request.
The POST method creates a name/value pairs that are passed in the body of the HTTP request message.
Name and describe some HTTP Status Codes and what they express to the requesting client.
When users try to access content on a server that is running Internet Information Services (IIS) through HTTP or File Transfer Protocol (FTP), IIS returns a numeric code that indicates the status of the request. This status code is recorded in the IIS log, and it may also be displayed in the Web browser or FTP client. The status code can indicate whether a particular request is successful or unsuccessful and can also reveal the exact reason why a request is unsuccessful. There are 5 groups ranging from 1xx - 5xx of http status codes exists.
101 - Switching protocols.
200 - OK. The client request has succeeded
302 - Object moved.
400 - Bad request.
500.13 - Web server is too busy.
Explain < @OutputCache% > and the usage of VaryByParam, VaryByHeader.
OutputCache is used to control the caching policies of an ASP.NET page or user control. To cache a page @OutputCache directive should be defined as follows < %@ OutputCache Duration="100" VaryByParam="none" % >
VaryByParam: A semicolon-separated list of strings used to vary the output cache. By default, these strings correspond to a query string value sent with GET method attributes, or a parameter sent using the POST method. When this attribute is set to multiple parameters, the output cache contains a different version of the requested document for each specified parameter. Possible values include none, *, and any valid query string or POST parameter name.
VaryByHeader: A semicolon-separated list of HTTP headers used to vary the output cache. When this attribute is set to multiple headers, the output cache contains a different version of the requested document for each specified header.
ASP.NET FAQ Four
How can you provide an alternating color scheme in a Repeater control?Using the AlternatintItemTemplate
What property must you set, and what method must you call in your code, in order to bind the data from some data source to the Repeater control?
Set the DataMember property to the name of the table to bind to. (If this property is not set, by default the first table in the dataset is used.)
DataBind method, use this method to bind data from a source to a server control. This method is commonly used after retrieving a data set through a database query.
What method do you use to explicitly kill a user s session?
You can dump (Kill) the session yourself by calling the method Session.Abandon.
ASP.NET automatically deletes a user's Session object, dumping its contents, after it has been idle for a configurable timeout interval. This interval, in minutes, is set in the
How do you turn off cookies for one page in your site?
Use Cookie.Discard property, Gets or sets the discard flag set by the server. When true, this property instructs the client application not to save the Cookie on the user's hard disk when a session ends.
Which two properties are on every validation control?
We have two common properties for every validation controls
1. Control to Validate,
2. Error Message.
How do you create a permanent cookie?
Permanent cookies are the ones that are most useful. Permanent cookies are available until a specified expiration date, and are stored on the hard disk. The location of cookies differs with each browser, but this doesn’t matter, as this is all handled by your browser and the server. If you want to create a permanent cookie called Name with a value of Nigel, which expires in one month, you’d use the following code
Response.Cookies ("Name") = "Nigel"
Response.Cookies ("Name"). Expires = DateAdd ("m", 1, Now ())
Which method do you use to redirect the user to another page without performing a round trip to the client?
Server.transfer
What is the transport protocol you use to call a Web service SOAP ?
HTTP Protocol
How do you register JavaScript for webcontrols ?
You can register javascript for controls using
When do you set IDENTITY impersonate="true" ?
Identity is a webconfig declaration under System.web, which helps to control the application Identity of the web applicaton. Which can be at any level(Machine,Site,application,subdirectory,or page), attribute impersonate with "true" as value specifies that client impersonation is used.
What are different templates available in Repeater,DataList and Datagrid ?
Templates enable one to apply complicated formatting to each of the items displayed by a control.Repeater control supports five types of templates.HeaderTemplate controls how the header of the repeater control is formatted.ItemTemplate controls the formatting of each item displayed.AlternatingItemTemplate controls how alternate items are formatted and the SeparatorTemplate displays a separator between each item displyed.FooterTemplate is used for controlling how the footer of the repeater control is formatted.The DataList and Datagrid supports two templates in addition to the above five.SelectedItem Template controls how a selected item is formatted and EditItemTemplate controls how an item selected for editing is formatted.
What is ViewState ? and how it is managed ?
ASP.NET ViewState is a new kind of state service that developers can use to track UI state on a per-user basis. Internally it uses an an old Web programming trick-roundtripping state in a hidden form field and bakes it right into the page-processing framework.It needs less code to write and maintain state in your Web-based forms.
What is web.config file ?
Web.config file is the configuration file for the Asp.net web application. There is one web.config file for one asp.net application which configures
the particular application. Web.config file is written in XML with specific tags having specific meanings.It includes databa which includes
connections,Session States,Error Handling,Security etc.
What is advantage of viewstate and what are benefits?
When a form is submitted in classic ASP, all form values are cleared. Suppose you have submitted a form with a lot of information and the server comes back with an error. You will have to go back to the form and correct the information. You click the back button, and what happens.......ALL form values are CLEARED, and you will have to start all over again! The site did not maintain your ViewState.With ASP .NET, the form reappears in the browser window together with all form values.This is because ASP .NET maintains your ViewState. The ViewState indicates the status of the page when submitted to the server.
Which property on a Combo Box do you set with a column name, prior to setting the DataSource, to display data in the combo box?
DataTextField and DataValueField
Which control would you use if you needed to make sure the values in two different controls matched?
CompareValidator is used to ensure that two fields are identical.
What is validationsummary server control?where it is used?.
The ValidationSummary control allows you to summarize the error messages from all validation controls on a Web page in a single location. The summary can be displayed as a list, a bulleted list, or a single paragraph, based on the value of the DisplayMode property. The error message displayed in the ValidationSummary control for each validation control on the page is specified by the ErrorMessage property of each validation control. If the ErrorMessage property of the validation control is not set, no error message is displayed in the ValidationSummary control for that validation control. You can also specify a custom title in the heading section of the ValidationSummary control by setting the HeaderText property.
You can control whether the ValidationSummary control is displayed or hidden by setting the ShowSummary property. The summary can also be displayed in a message box by setting the ShowMessageBox property to true.
What is the sequence of operation takes place when a page is loaded?
BeginTranaction - only if the request is transacted
Init - every time a page is processed
LoadViewState - Only on postback
ProcessPostData1 - Only on postback
Load - every time
ProcessData2 - Only on Postback
RaiseChangedEvent - Only on Postback
RaisePostBackEvent - Only on Postback
PreRender - everytime
BuildTraceTree - only if tracing is enabled
SaveViewState - every time
Render - Everytime
End Transaction - only if the request is transacted
Trace.EndRequest - only when tracing is enabled
UnloadRecursive - Every request
Difference between asp and asp.net?.
"ASP (Active Server Pages) and ASP.NET are both server side technologies for building web sites and web applications, ASP.NET is Managed compiled code - asp is interpreted. and ASP.net is fully Object oriented. ASP.NET has been entirely re-architected to provide a highly productive programming experience based on the .NET Framework, and a robust infrastructure for building reliable and scalable web
applications."
Name the validation control available in asp.net?.
RequiredField, RangeValidator,RegularExpression,Custom validator,compare Validator
What are the various ways of securing a web site that could prevent from hacking etc .. ?
1) Authentication/Authorization
2) Encryption/Decryption
3) Maintaining web servers outside the corporate firewall. etc.,
What is the difference between in-proc and out-of-proc?
An inproc is one which runs in the same process area as that of the client giving tha advantage of speed but the disadvantage of stability becoz if it crashes it takes the client application also with it.Outproc is one which works outside the clients memory thus giving stability to the client, but we have to compromise a bit on speed.
ASP.NET FAQ Three
What is different between web.config & Machine.config ?Web.config & machine.config both are configuration files.Web.config contains settings specific to an application where as machine.config contains settings to a computer. The Configuration system first searches settings in machine.config file & then looks in application configuration files.Web.config, can appear in multiple directories on an ASP.NET Web application server. Each Web.config file applies configuration settings to its own directory and all child directories below it. There is only Machine.config file on a web server.
How do you turn off cookies for one page in your site?
Since no Page Level directive is present, I am afraid that cant be done.
How do you create a permanent cookie?
Permanent cookies are available until a specified expiration date, and are stored on the hard disk.So Set the 'Expires' property any value greater than DataTime.MinValue with respect to the current datetime. If u want the cookie which never expires set its Expires property equal to DateTime.maxValue.
Which method do you use to redirect the user to another page without performing a round trip to the client?
Server.Transfer and Server.Execute
What property do you have to set to tell the grid which page to go to when using the Pager object?
CurrentPageIndex
Should validation (did the user enter a real date) occur server-side or client-side? Why?
It should occur both at client-side and Server side.By using expression validator control with the specified expression ie.. the regular expression provides the facility of only validatating the date specified is in the correct format or not. But for checking the date where it is the real data or not should be done at the server side, by getting the system date ranges and checking the date whether it is in between that range or not.
What does the "EnableViewState" property do? Why would I want it on or off?
Enable ViewState turns on the automatic state management feature that enables server controls to re-populate their values on a round trip without requiring you to write any code. This feature is not free however, since the state of a control is passed to and from the server in a hidden form field. You should be aware of when ViewState is helping you and when it is not. For example, if you are binding a control to data on every round trip, then you do not need the control to maintain it's view state, since you will wipe out any re-populated data in any case. ViewState is enabled for all server controls by default. To disable it, set the EnableViewState property of the control to false.
What is the difference between Server.Transfer and Response.Redirect? Why would I choose one over the other?
Server.Transfer() : client is shown as it is on the requesting page only, but the all the content is of the requested page. Data can be persist accros the pages using Context.Item collection, which is one of the best way to transfer data from one page to another keeping the page state alive.
Response.Dedirect() :client know the physical location (page name and query string as well). Context.Items loses the persisitance when nevigate to destination page. In earlier versions of IIS, if we wanted to send a user to a new Web page, the only option we had was Response.Redirect. While this method does accomplish our goal, it has several important drawbacks. The biggest problem is that this method causes each page to be treated as a separate transaction. Besides making it difficult to maintain your transactional integrity, Response.Redirect introduces some additional headaches. First, it prevents good encapsulation of code. Second, you lose access to all of the properties in the Request object. Sure, there are workarounds, but they're difficult. Finally, Response.Redirect necessitates a round trip to the client, which, on high-volume sites, causes scalability problems. As you might suspect, Server.Transfer fixes all of these problems. It does this by performing the transfer on the server without requiring a roundtrip to the client.
Can you give an example of when it would be appropriate to use a web service as opposed to a non-serviced .NET component?
Communicating through a Firewall When building a distributed application with 100s/1000s of users spread over multiple locations, there is always the problem of communicating between client and server because of firewalls and proxy servers. Exposing your middle tier components as Web Services and invoking the directly from a Windows UI is a very valid option.
Application Integration When integrating applications written in various languages and running on disparate systems. Or even applications running on the same platform that have been written by separate vendors.
Business-to-Business Integration This is an enabler for B2B intergtation which allows one to expose vital business processes to authorized supplier and customers. An example would be exposing electronic ordering and invoicing, allowing customers to send you purchase orders and suppliers to send you invoices electronically.
Software Reuse This takes place at multiple levels. Code Reuse at the Source code level or binary componet-based resuse. The limiting factor here is that you can reuse the code but not the data behind it. Webservice overcome this limitation. A scenario could be when you are building an app that aggregates the functionality of serveral other Applicatons. Each of these functions could be performed by individual apps, but there is value in perhaps combining the the multiple apps to present a unifiend view in a Portal or Intranet.
When not to use Web Services: Single machine Applicatons When the apps are running on the same machine and need to communicate with each other use a native API. You also have the options of using component technologies such as COM or .NET Componets as there is very little overhead.
Homogeneous Applications on a LAN If you have Win32 or Winforms apps that want to communicate to their server counterpart. It is much more efficient to use DCOM in the case of Win32 apps and .NET Remoting in the case of .NET Apps
Can you give an example of what might be best suited to place in the Application_Start and Session_Start subroutines?
The Application_Start event is guaranteed to occur only once throughout the lifetime of the application. It's a good place to initialize global variables. For example, you might want to retrieve a list of products from a database table and place the list in application state or the Cache object. SessionStateModule exposes both Session_Start and Session_End events.
What are the advantages and disadvantages of viewstate?
The primary advantages of the ViewState feature in ASP.NET are:
1. Simplicity. There is no need to write possibly complex code to store form data between page submissions.
2. Flexibility. It is possible to enable, configure, and disable ViewState on a control-by-control basis, choosing to persist the values of some fields but not others.
There are, however a few disadvantages that are worth pointing out:
1. Does not track across pages. ViewState information does not automatically transfer from page to page. With the session
approach, values can be stored in the session and accessed from other pages. This is not possible with ViewState, so storing
data into the session must be done explicitly.
2. ViewState is not suitable for transferring data for back-end systems. That is, data still has to be transferred to the back
end using some form of data object.
ASP.NET FAQ Two
Is it necessary to lock application state before accessing it?Only if you're performing a multistep update and want the update to be treated as an atomic operation.
Here's an example:
Application.Lock ();
Application["ItemsSold"] = (int) Application["ItemsSold"] + 1;
Application["ItemsLeft"] = (int) Application["ItemsLeft"] - 1;
Application.UnLock ();
By locking application state before updating it and unlocking it afterwards, you ensure that another request being processed on another thread doesn't read application state at exactly the wrong time and see an inconsistent view of it. If I update session state, should I lock it, too? Are concurrent accesses by multiple requests executing on multiple threads a concern with session state?Concurrent accesses aren't an issue with session state, for two reasons. One, it's unlikely that two requests from the same user will overlap. Two, if they do overlap, ASP.NET locks down session state during request processing so that two threads can't touch it at once. Session state is locked down when the HttpApplication instance that's processing the request fires an AcquireRequestState event and unlocked when it fires a ReleaseRequestState event.
Do ASP.NET forms authentication cookies provide any protection against replay attacks? Do they, for example, include the client's IP address or anything else that would distinguish the real client from an attacker?
No. If an authentication cookie is stolen, it can be used by an attacker. It's up to you to prevent this from happening by using an encrypted communications channel (HTTPS). Authentication cookies issued as session cookies, do, however,include a time-out valid that limits their lifetime. So a stolen session cookie can only be used in replay attacks as long as the ticket inside the cookie is valid. The default time-out interval is 30 minutes.You can change that by modifying the timeout attribute accompanying the
How do I send e-mail from an ASP.NET application?
MailMessage message = new MailMessage ();
message.From =
message.To =
message.Subject = "Scheduled Power Outage";
message.Body = "Our servers will be down tonight.";
SmtpMail.SmtpServer = "localhost";
SmtpMail.Send (message);
MailMessage and SmtpMail are classes defined in the .NET Framework Class Library's System.Web.Mail namespace. Due to a security change made to ASP.NET just before it shipped, you need to set SmtpMail's SmtpServer property to "localhost" even though "localhost" is the default. In addition, you must use the IIS configuration applet to enable localhost (127.0.0.1) to relay messages through the local SMTP service.
What are VSDISCO files?
VSDISCO files are DISCO files that support dynamic discovery of Web services. If you place the following VSDISCO file in a directory on your Web server, for example, it returns references to all ASMX and DISCO files in the host directory.
How does dynamic discovery work?
ASP.NET maps the file name extension VSDISCO to an HTTP handler that scans the host directory and subdirectories for ASMX and DISCO files and returns a dynamically generated DISCO document. A client who requests a VSDISCO file gets back what appears to be a static DISCO document.
Note that VSDISCO files are disabled in the release version of ASP.NET. You can reenable them by uncommenting the line in the
Is it possible to prevent a browser from caching an ASPX page?
Just call SetNoStore on the HttpCachePolicy object exposed through the Response object's Cache property, as demonstrated here:
Response.Cache.SetNoStore ();
Response.Write (DateTime.Now.ToLongTimeString ());
SetNoStore works by returning a Cache-Control: private, no-store header in the HTTP response. In this example, it prevents caching of a Web page that shows the current time.
What does AspCompat="true" mean and when should I use it?
AspCompat is an aid in migrating ASP pages to ASPX pages. It defaults to false but should be set to true in any ASPX file that creates apartment-threaded COM objects--that is, COM objects registered ThreadingModel=Apartment. That includes all COM objects written with Visual Basic 6.0. AspCompat should also be set to true (regardless of threading model) if the page creates COM objects that access intrinsic ASP objects such as Request and Response. The following directive sets AspCompat to true:
Setting AspCompat to true does two things. First, it makes intrinsic ASP objects available to the COM components by placing unmanaged wrappers around the equivalent ASP.NET objects. Second, it improves the performance of calls that the page places to apartment- threaded COM objects by ensuring that the page (actually, the thread that processes the request for the page) and the COM objects it creates share an apartment. AspCompat="true" forces ASP.NET request threads into single-threaded apartments (STAs). If those threads create COM objects marked ThreadingModel=Apartment, then the objects are created in the same STAs as the threads that created them. Without AspCompat="true," request threads run in a multithreaded apartment (MTA) and each call to an STA-based COM object incurs a performance hit when it's marshaled across apartment boundaries.
Do not set AspCompat to true if your page uses no COM objects or if it uses COM objects that don't access ASP intrinsic objects and that are registered ThreadingModel=Free or ThreadingModel=Both.
Explain the differences between Server-side and Client-side code?
Server side scripting means that all the script will be executed by the server and interpreted as needed. ASP doesn't have some of the functionality like sockets, uploading, etc. For these you have to make a custom components usually in VB or VC++. Client side scripting means that the script will be executed immediately in the browser such as form field validation, clock, email validation, etc. Client side scripting is usually done in VBScript or JavaScript. Download time, browser compatibility, and visible code - since JavaScript and VBScript code is included in the HTML page, then anyone can see the code by viewing the page source. Also a possible security hazards for the client computer.
What type of code (server or client) is found in a Code-Behind class?
C#
Should validation (did the user enter a real date) occur server-side or client-side? Why?
Client-side validation because there is no need to request a server side date when you could obtain a date from the client machine.
What are ASP.NET Web Forms? How is this technology different than what is available though ASP?
Web Forms are the heart and soul of ASP.NET. Web Forms are the User Interface (UI) elements that give your Web applications their look and feel. Web Forms are similar to Windows Forms in that they provide properties, methods, and events for the controls that are placed onto them. However, these UI elements render themselves in the appropriate markup language required by the request, e.g. HTML. If you use Microsoft Visual Studio .NET, you will also get the familiar drag-and-drop interface used to create your UI for your Web application.
What is the difference between Server.Transfer and Response.Redirect? Why would I choose one over the other?
In earlier versions of IIS, if we wanted to send a user to a new Web page, the only option we had was Response.Redirect. While this method does accomplish our goal, it has several important drawbacks. The biggest problem is that this method causes each page to be treated as a separate transaction. Besides making it difficult to maintain your transactional integrity, Response.Redirect introduces some additional headaches. First, it prevents good encapsulation of code. Second, you lose access to all of the properties in the Request object. Sure, there are workarounds, but they're difficult. Finally, Response.Redirect necessitates a round trip to the client, which, on high-volume sites, causes scalability problems.As you might suspect, Server.Transfer fixes all of these problems. It does this by performing the transfer on the server without requiring a roundtrip to the client.
How can you provide an alternating color scheme in a Repeater control?AlternatingItemTemplate Like the ItemTemplate element, but rendered for every other row (alternating items) in the Repeater control. You can specify a different appearance for the AlternatingItemTemplate element by setting its style properties.
Which template must you provide, in order to display data in a Repeater control?ItemTemplate
What event handlers can I include in Global.asax?
Application_Start,
Application_End,
Application_AcquireRequestState,
Application_AuthenticateRequest,
Application_AuthorizeRequest,
Application_BeginRequest,
Application_Disposed,
Application_EndRequest,
Application_Error,
Application_PostRequestHandlerExecute,
Application_PreRequestHandlerExecute,
Application_PreSendRequestContent,
Application_PreSendRequestHeaders,
Application_ReleaseRequestState,
Application_ResolveRequestCache,
Application_UpdateRequestCache,
Session_Start,Session_End
You can optionally include "On" in any of method names. For example, you can name a BeginRequest event handler.Application_BeginRequest or Application_OnBeginRequest.You can also include event handlers in Global.asax for events fired by custom HTTP modules.Note that not all of the event handlers make sense for Web Services (they're designed for ASP.NET applications in general, whereas .NET XML Web Services are specialized instances of an ASP.NET app). For example, the Application_AuthenticateRequest and Application_AuthorizeRequest events are designed to be used with ASP.NET Forms authentication.
ASP.NET FAQ One
What is view state and use of it?The current property settings of an ASP.NET page and those of any ASP.NET server controls contained within the page. ASP.NET can detect when a form is requested for the first time versus when the form is posted (sent to the server), which allows you to program accordingly.
What are user controls and custom controls?
Custom controls:
A control authored by a user or a third-party software vendor that does not belong to the .NET Framework class library. This is a generic term that includes user controls. A custom server control is used in Web Forms (ASP.NET pages). A custom client control is used in Windows Forms applications.
User Controls:
In ASP.NET: A user-authored server control that enables an ASP.NET page to be re-used as a server control. An ASP.NET user control is authored declaratively and persisted as a text file with an .ascx extension. The ASP.NET page framework compiles a user control on the fly to a class that derives from the System.Web.UI.UserControl class.
What are the validation controls?
A set of server controls included with ASP.NET that test user input in HTML and Web server controls for programmer-defined requirements. Validation controls perform input checking in server code. If the user is working with a browser that supports DHTML, the validation controls can also perform validation using client script.
What's the difference between Response.Write() andResponse.Output.Write()?
The latter one allows you to write formattedoutput.
What methods are fired during the page load?
Init() When the page is instantiated, Load() - when the page is loaded into server memory,PreRender () - the brief moment before the page is displayed to the user as HTML, Unload() - when page finishes loading.
Where does the Web page belong in the .NET Framework class hierarchy?
System.Web.UI.Page
Where do you store the information about the user's locale?
System.Web.UI.Page.Culture
What's the difference between Codebehind="MyCode.aspx.cs" and Src="MyCode.aspx.cs"?
CodeBehind is relevant to Visual Studio.NET only.
What's a bubbled event?
When you have a complex control, likeDataGrid, writing an event processing routine for each object (cell, button,row, etc.) is quite tedious. The controls can bubble up their eventhandlers, allowing the main DataGrid event handler to take care of its constituents.Suppose you want a certain ASP.NET function executed on MouseOver over a certain button.
Where do you add an event handler?
It's the Attributesproperty, the Add function inside that property. e.g. btnSubmit.Attributes.Add("onMouseOver","someClientCode();")
What data type does the RangeValidator control support?
Integer,String and Date.
What are the different types of caching?
Caching is a technique widely used in computing to increase performance by keeping frequently accessed or expensive data in memory. In context of web application, caching is used to retain the pages or data across HTTP requests and reuse them without the expense of recreating them.ASP.NET has 3 kinds of caching strategiesOutput CachingFragment CachingData
CachingOutput Caching: Caches the dynamic output generated by a request. Some times it is useful to cache the output of a website even for a minute, which will result in a better performance. For caching the whole page the page should have OutputCache directive.
Fragment Caching: Caches the portion of the page generated by the request. Some times it is not practical to cache the entire page, in such cases we can cache a portion of page
Data Caching: Caches the objects programmatically. For data caching asp.net provides a cache object for eg: cache["States"] = dsStates;
What do you mean by authentication and authorization?
Authentication is the process of validating a user on the credentials (username and password) and authorization performs after authentication. After Authentication a user will be verified for performing the various tasks, It access is limited it is known as authorization.
What are different types of directives in .NET?
@Page: Defines page-specific attributes used by the ASP.NET page parser and compiler. Can be included only in .aspx files
@Control: Defines control-specific attributes used by the ASP.NET page parser and compiler. Can be included only in .ascx files.
@Import: Explicitly imports a namespace into a page or user control. The Import directive cannot have more than one namespace attribute. To import multiple namespaces, use multiple @Import directives.
@Implements: Indicates that the current page or user control implements the specified .NET framework interface.
@Register: Associates aliases with namespaces and class names for concise notation in custom server control syntax.
@Assembly: Links an assembly to the current page during compilation, making all the assembly's classes and interfaces available for use on the page.
@OutputCache: Declaratively controls the output caching policies of an ASP.NET page or a user control contained in a page
@Reference: Declaratively indicates that another user control or page source file should be dynamically compiled and linked against the page in which this directive is declared.
How do I debug an ASP.NET application that wasn't written with Visual Studio.NET and that doesn't use code-behind?
Start the DbgClr debugger that comes with the .NET Framework SDK, open the file containing the code you want to debug, and set your breakpoints. Start the ASP.NET application. Go back to DbgClr, choose Debug Processes from the Tools menu, and select aspnet_wp.exe from the list of processes. (If aspnet_wp.exe doesn't appear in the list,check the "Show system processes" box.) Click the Attach button to attach to aspnet_wp.exe and begin debugging.Be sure to enable debugging in the ASPX file before debugging it with DbgClr. You can enable tell ASP.NET to build debug executables by placing a
statement at the top of an ASPX file or a
Can a user browsing my Web site read my Web.config or Global.asax files?
No. The
What's the difference between Page.RegisterClientScriptBlock and Page.RegisterStartupScript?
RegisterClientScriptBlock is for returning blocks of client-side script containing functions. RegisterStartupScript is for returning blocks of client-script not packaged in functions-in other words, code that's to execute when the page is loaded. The latter positions script blocks near the end of the document so elements on the page that the script interacts are loaded before the script runs.