Learn About Extension Methods

Hello C# beginners. In this blog, we will see an extension method via a concrete example.

Hello C# beginners. In this blog, we will see what an extension method via a concrete example.

Why use extension Methods?

If we need to add a method called ExtensionMethod to Int class: we should create a derivative class and add our methods to it, correct?

The response is NO: Because int class is sealed so we can’t inherit from it but .NET framework contains a powerful solution which is “Extension Methods.”

How could we do that?

To add an extension Method of int type, add a static method, the first attribute type must be  (this int)

This is used to specify that int is our extended Type.

public static type ExtensionMethod (this int param, params...)
        {
          // instructions
        }

 

To use this extension:

int i;
i.ExtensionMethod(params ..)

 

Advantages

No Need to create a derivate class.

No need to change original class.

No need to recompile.

Calling of an extension method is simple.

For more details, you can read the links below.

• https://msdn.microsoft.com/en-us/library/bb383977.aspx
• https://msdn.microsoft.com/en-us/library/bb311042.aspx