Use of Extension method in Dot Net.

vishalneeraj-24503
Posted by vishalneeraj-24503 under ASP.NET category on | Points: 40 | Views : 915
Extension methods are used for the Readability purpose.It's a static method.
In C# we have to create STATIC CLASS but in VB.Net, we have to create a MODULE like below snippets:-

Note:-
1). In C#, we have to give this keyword in the 1st parameter list
2). In VB.Net,we have to define <System.Runtime.CompilerServices.Extension()> _ attribute in function.

//C#
public static class Text_Validation
{
}

//VB.Net
Public Module Text_Validation
End Module

We can understand this by an example:-

//In C#:-

public static class Text_Validation
{
public static string Add_Text(this string str)
{
if(string.IsNullOrEmpty(str))
{
str = "Add Text";
}
return str;
}
}

//In VB.Net:-

Public Module Text_Validation

<System.Runtime.CompilerServices.Extension()> _
Public Function Add_Text(ByVal str As String) As String
If String.IsNullOrEmpty(str) Then
str = "Add Text"
End If
Return str
End Function
End Module

//Our aspx page will look like this:-
<asp:TextBox ID="txt_contents" runat="server"></asp:TextBox>

Protected Sub Page_Load(sender As Object, e As EventArgs) Handles Me.Load
txt_contents.Text = txt_contents.Text.Add_Text()
End Sub

//If the TextBox is empty then it will add "Add Text" in TextBox.

Comments or Responses

Login to post response