How to extend an user defined class using Extension Method?

Tags

C#

In this post we are going to discuss how to write an extension method for an existing class. Below code will help you to write an extension method for an existing class.

Main class :

public class MainClass
{
public int x = 100;
public void Method1()
{
Console.WriteLine(“Method1”);
}
public void Method2()
{
Console.WriteLine(“Method2”);
}
}

Extension method for main class :

public static class ExtendMainClass
{
public static void Method3(this MainClass obj)
{
Console.WriteLine(“method3”);
}
public static void Method4(this MainClass obj,int x){

Console.WriteLine(“method4 : “+x);
}

}

How to call Extension Method :
MainClass obj = new MainClass();
obj.Method3();
obj.Method4(10);