A partial class can span multiple source files. : Partial Class « Class « C# / CSharp Tutorial

1. C# / CSharp Tutorial
2. Class
3. Partial Class

using System;


public partial class MyClass {

    public void CoreMethodA() {
        Console.WriteLine("MyClass.CoreA");
    }
}

public class Starter {
    public static void Main() {
        MyClass obj = new MyClass();
        obj.CoreMethodA();
        obj.ExtendedMethodA();
    }
}


public partial class MyClass {

    public void ExtendedMethodA() {
        Console.WriteLine("MyClass.ExtendedA");
    }
}