VB.NET and C# Code Syntax

Generally if we are working on multiple projects that have to use differenet languages like VB.NET and C#, most of the time it's very difficult to remember all the syntax changes in those languages. Here i have added the vb.net and c# syntax formats. Hope that it will be useful.

Variable Declarations

VB.NET

Dim x As Integer

Dim s As String

Dim s1, s2 As String

Dim o 'Implicitly Object

Dim obj As New Object()

Public name As String

C#

int x;

String s;

String s1, s2;

Object o;

Object obj = new Object();

public String name;

Constants

VB.NET

Const MAX_STUDENTS As Integer = 25

' Can set to a const or var; may be initialized in a constructor
ReadOnly MIN_DIAMETER As Single = 4.93

C#

const int MAX_STUDENTS = 25;

// Can set to a const or var; may be initialized in a constructor
readonly float MIN_DIAMETER = 4.93f;

Statements

VB.NET

Response.Write("foo")

C#

Response.Write("foo");

Comments

VB.NET

' This is a comment

' This

' is

' a

' multiline

' comment

C#

// This is a comment

/*

This

is

a

multiline

comment

*/

Accessing Indexed Properties

VB.NET

Dim s, value As String

s = Request.QueryString("Name")

value = Request.Cookies("Key").Value

'Note that default non-indexed properties

'must be explicitly named in VB.NET

C#

String s = Request.QueryString["Name"];

String value = Request.Cookies["key"];

Declaring Indexed Properties

VB.NET

' Default Indexed Property

Public Default ReadOnly Property DefaultProperty(Name As String) As String

Get

Return CStr(lookuptable(name))

End Get

End Property

C#

// Default Indexed Property

public String this[String name] {

get {

return (String) lookuptable[name];

}

}

Declaring Simple Properties

VB.NET

Public Property Name As String

Get

...

Return ...

End Get

Set

... = Value

End Set

End Property

ex:

Private _size As Integer

Public Property Size() As Integer
Get
Return _size
End Get
Set (ByVal Value As Integer)
If Value < 0 Then
_size = 0
Else
_size = Value
End If
End Set
End Property

foo.Size += 1

C#

public String name {

get {

...

return ...;

}

set {

... = value;

}

}

ex:

private int _size;

public int Size {
get {
return _size;
}
set {
if (value < 0)
_size = 0;
else
_size = value;
}
}

foo.Size++;

Declare and Use an Enumeration

VB.NET

' Declare the Enumeration

Public Enum MessageSize

Small = 0

Medium = 1

Large = 2

End Enum

' Create a Field or Property

Public MsgSize As MessageSize

' Assign to the property using the Enumeration values

MsgSize = small

C#

// Declare the Enumeration

public enum MessageSize {

Small = 0,

Medium = 1,

Large = 2

}

// Create a Field or Property

public MessageSize msgsize;

// Assign to the property using the Enumeration values

msgsize = Small;

Enumerating a Collection

VB.NET

Dim S As String

For Each S In Coll

...

Next

' Array or collection looping
Dim names As String() = {"Fred", "Sue", "Barney"}
For Each s As String In names
Response.write(s)
Next

C#

foreach ( String s in coll ) {

...

}

// Array or collection looping
string[] names = {"Fred", "Sue", "Barney"};
foreach (string s in names)
Response.Write(s);

Declare and Use Methods

VB.NET

' Declare a void return function

Sub VoidFunction()

...

End Sub

' Declare a function that returns a value

Function StringFunction() As String

...

Return CStr(val)

End Function

' Declare a function that takes and returns values

Function ParmFunction(a As String, b As String) As String

...

Return CStr(A & B &#41;

End Function

' Use the Functions

VoidFunction()

Dim s1 As String = StringFunction()

Dim s2 As String = ParmFunction("Hello", "World!")

C#

// Declare a void return function

void voidfunction() {

...

}

// Declare a function that returns a value

String stringfunction() {

...

return (String) val;

}

// Declare a function that takes and returns values

String parmfunction(String a, String b) {

...

return (String) (a + b);

}

// Use the Functions

voidfunction();

String s1 = stringfunction();

String s2 = parmfunction("Hello", "World!");

Custom Attributes

VB.NET

' Stand-alone attribute

<STAThread>

' Attribute with parameters

<DllImport("ADVAPI32.DLL")>

' Attribute with named parameters

<DllImport("KERNEL32.DLL", CharSet:=CharSet.Auto)>

C#

// Stand-alone attribute

[STAThread]

// Attribute with parameters

[DllImport("ADVAPI32.DLL")]

// Attribute with named parameters

[DllImport("KERNEL32.DLL", CharSet=CharSet.Auto)]

Arrays

VB.NET

Dim a(2) As String

a(0) = "1"

a(1) = "2"

a(2) = "3"

Dim a(2,2) As String

a(0,0) = "1"

a(1,0) = "2"

a(2,0) = "3"

C#

String[] a = new String[3];

a[0] = "1";

a[1] = "2";

a[2] = "3";

String[][] a = new String[3][3];

a[0][0] = "1";

a[1][0] = "2";

a[2][0] = "3";

Initialization

VB.NET

Dim s As String = "Hello World"

Dim i As Integer = 1

Dim a() As Double = { 3.00, 4.00, 5.00 }

C#

String s = "Hello World";

int i = 1;

double[] a = { 3.00, 4.00, 5.00 };

If Statements

VB.NET

If Not (Request.QueryString = Nothing)

...

End If

greeting = IIf(age < 20, "What's up?", "Hello")

C#

if (Request.QueryString != null) {

...

}

greeting = age < 20 ? "What's up?" : "Hello";

Case Statements

VB.NET

Select Case FirstName

Case "John"

...

Case "Paul"

...

Case "Ringo"

...

Case Else

...

End Select

C#

switch (FirstName) {

case "John" :

...

break;

case "Paul" :

...

break;

case "Ringo" :

...

break;

default:

...

break;

}

For Loops

VB.NET

Dim I As Integer

For I = 0 To 2

a(I) = "test"

Next

C#

for (int i=0; i<3; i++)

a(i) = "test";

While Loops

VB.NET

Dim I As Integer

I = 0

Do While I < 3

Response.write(I.ToString())

I += 1

Loop

C#

int i = 0;

while (i<3) {

Response.Write(i.ToString());

i += 1;

}

Exception Handling

VB.NET

Try

' Code that throws exceptions

Catch E As OverflowException

' Catch a specific exception

Catch E As Exception

' Catch the generic exceptions

Finally

' Execute some cleanup code

End Try

C#

try {

// Code that throws exceptions

} catch(OverflowException e) {

// Catch a specific exception

} catch(Exception e) {

// Catch the generic exceptions

} finally {

// Execute some cleanup code

}

String Concatenation

VB.NET

' Using Strings

Dim s1, s2 As String

s2 = "hello"

s2 &= &#34; world"

s1 = s2 & &#34; !!!"

' Using StringBuilder class for performance

Dim s3 As New StringBuilder()

s3.Append("hello")

s3.Append(" world")

s3.Append(" !!!")

C#

// Using Strings

String s1;

String s2 = "hello";

s2 += " world";

s1 = s2 + " !!!";

// Using StringBuilder class for performance

StringBuilder s3 = new StringBuilder();

s3.Append("hello");

s3.Append(" world");

s3.Append(" !!!");

Event Handler Delegates

VB.NET

Sub MyButton_Click(Sender As Object, E As EventArgs)

...

End Sub

C#

void MyButton_Click(Object sender, EventArgs E) {

...

}

Declare Events

VB.NET

' Create a public event

Public Event MyEvent(Sender as Object, E as EventArgs)

' Create a method for firing the event

Protected Sub OnMyEvent(E As EventArgs)

RaiseEvent MyEvent(Me, E)

End Sub

C#

// Create a public event

public event EventHandler MyEvent;

// Create a method for firing the event

protected void OnMyEvent(EventArgs e) {

MyEvent(this, e);

}

Add or Remove Event Handlers to Events

VB.NET

AddHandler Control.Change, AddressOf Me.ChangeEventHandler

RemoveHandler Control.Change, AddressOf Me.ChangeEventHandler

C#

Control.Change += new EventHandler(this.ChangeEventHandler);

Control.Change -= new EventHandler(this.ChangeEventHandler);

Casting

VB.NET

Dim obj As MyObject

Dim iObj As IMyObject

obj = Session("Some Value")

iObj = CType(obj, IMyObject)

C#

MyObject obj = (MyObject)Session["Some Value"];

IMyObject iObj = obj;

Conversion

VB.NET

Dim i As Integer

Dim s As String

Dim d As Double

i = 3

s = i.ToString()

d = CDbl(s)

' See also CDbl(...), CStr(...), ...

C#

int i = 3;

String s = i.ToString();

double d = Double.Parse(s);

Using Objects

VB.NET

Dim hero As SuperHero = New SuperHero
' or
Dim hero As New SuperHero

With hero
.Name = "SpamMan"
.PowerLevel = 3
End With

hero.Defend("Laura Jones")
hero.Rest() ' Calling Shared method
' or
SuperHero.Rest()

Dim hero2 As SuperHero = hero ' Both reference the same object
hero2.Name = "WormWoman"
Response.Write(hero.Name) ' Prints WormWoman

hero = Nothing ' Free the object

If hero Is Nothing Then _
hero = New SuperHero

Dim obj As Object = New SuperHero
If TypeOf obj Is SuperHero Then _
Response.Write("Is a SuperHero object.")

' Mark object for quick disposal
Using reader As StreamReader = File.OpenText("test.txt")
Dim line As String = reader.ReadLine()
While Not line Is Nothing
Response.Write(line)
line = reader.ReadLine()
End While
End Using

C#

SuperHero hero = new SuperHero();

// No "With" construct
hero.Name = "SpamMan";
hero.PowerLevel = 3;

hero.Defend("Laura Jones");
SuperHero.Rest(); // Calling static method

SuperHero hero2 = hero; // Both reference the same object
hero2.Name = "WormWoman";
Response.Write (hero.Name); // Prints WormWoman

hero = null ; // Free the object

if (hero == null)
hero = new SuperHero();

Object obj = new SuperHero();
if (obj is SuperHero)
Response.Write ("Is a SuperHero object.");

// Mark object for quick disposal
using (StreamReader reader = File.OpenText("test.txt")) {
string line;
while ((line = reader.ReadLine()) != null)
Response.Write(line);
}

Class Definition with Inheritance

VB.NET

Imports System

Namespace MySpace

Public Class Foo : Inherits Bar

Dim x As Integer

Public Sub New()

MyBase.New()

x = 4

End Sub

Public Sub Add(x As Integer)

Me.x = Me.x + x

End Sub

Overrides Public Function GetNum() As Integer

Return x

End Function

End Class

End Namespace

' VB.NETc /out:libraryVB.NET.dll /t:library

' library.VB.NET

C#

using System;

namespace MySpace {

public class Foo : Bar {

int x;

public Foo() { x = 4; }

public void Add(int x) { this.x += x; }

override public int GetNum() { return x; }

}

}

// csc /out:librarycs.dll /t:library

// library.cs

Implementing an Interface

VB.NET

Public Class MyClass : Implements IEnumerable

...

Function IEnumerable_GetEnumerator() As IEnumerator Implements IEnumerable.GetEnumerator

...

End Function

End Class

C#

public class MyClass : IEnumerable {

...

IEnumerator IEnumerable.GetEnumerator() {

...

}

}

Structs

VB.NET

Structure StudentRecord
Public name As String
Public gpa As Single

Public Sub New(ByVal name As String, ByVal gpa As Single)
Me.name = name
Me.gpa = gpa
End Sub
End Structure

Dim stu As StudentRecord = New StudentRecord("Bob", 3.5)
Dim stu2 As StudentRecord = stu

stu2.name = "Sue"
Response.Write(stu.name) ' Prints Bob
Response.Write (stu2.name) ' Prints Sue

C#

struct StudentRecord {
public string name;
public float gpa;

public StudentRecord(string name, float gpa) {
this.name = name;
this.gpa = gpa;
}
}

StudentRecord stu = new StudentRecord("Bob", 3.5f);
StudentRecord stu2 = stu;

stu2.name = "Sue";
Response.Write (stu.name); // Prints Bob
Response.Write (stu2.name); // Prints Sue

Constructors / Destructors

VB.NET

Class SuperHero
Private _powerLevel As Integer

Public Sub New()
_powerLevel = 0
End Sub

Public Sub New(ByVal powerLevel As Integer)
Me._powerLevel = powerLevel
End Sub

Protected Overrides Sub Finalize()
' Desctructor code to free unmanaged resources
MyBase.Finalize()
End Sub
End Class

C#

class SuperHero {
private int _powerLevel;

public SuperHero() {
_powerLevel = 0;
}

public SuperHero(int powerLevel) {
this._powerLevel= powerLevel;
}

~SuperHero() {
// Destructor code to free unmanaged resources.
// Implicitly creates a Finalize method
}
}

File I/O

VB.NET

Imports System.IO

' Write out to text file
Dim writer As StreamWriter = File.CreateText("c:\myfile.txt")
writer.WriteLine("Out to file.")
writer.Close()

' Read all lines from text file
Dim reader As StreamReader = File.OpenText("c:\myfile.txt")
Dim line As String = reader.ReadLine()
While Not line Is Nothing
Console.WriteLine(line)
line = reader.ReadLine()
End While
reader.Close()

' Write out to binary file
Dim str As String = "Text data"
Dim num As Integer = 123
Dim binWriter As New BinaryWriter(File.OpenWrite("c:\myfile.dat"))
binWriter.Write(str)
binWriter.Write(num)
binWriter.Close()

' Read from binary file
Dim binReader As New BinaryReader(File.OpenRead("c:\myfile.dat"))
str = binReader.ReadString()
num = binReader.ReadInt32()
binReader.Close()

C#

using System.IO;

// Write out to text file
StreamWriter writer = File.CreateText("c:\\myfile.txt");
writer.WriteLine("Out to file.");
writer.Close();

// Read all lines from text file
StreamReader reader = File.OpenText("c:\\myfile.txt");
string line = reader.ReadLine();
while (line != null) {
Console.WriteLine(line);
line = reader.ReadLine();
}
reader.Close();

// Write out to binary file
string str = "Text data";
int num = 123;
BinaryWriter binWriter = new BinaryWriter(File.OpenWrite("c:\\myfile.dat"));
binWriter.Write(str);
binWriter.Write(num);
binWriter.Close();

// Read from binary file
BinaryReader binReader = new BinaryReader(File.OpenRead("c:\\myfile.dat"));
str = binReader.ReadString();
num = binReader.ReadInt32();
binReader.Close();

posted by Vijay Kumar @ 11/05/2006 04:33:00 PM