Delegates

// compose.cs
using System;

delegate void MyDelegate(string s);

class MyClass
{
public static void Hello(string s)
{
Console.WriteLine(" Hello, {0}!", s);
}

public static void Goodbye(string s)
{
Console.WriteLine(" Goodbye, {0}!", s);
}

public static void Main()
{
MyDelegate a, b, c, d;

// Create the delegate object a that references
// the method Hello:
a = new MyDelegate(Hello);
// Create the delegate object b that references
// the method Goodbye:
b = new MyDelegate(Goodbye);
// The two delegates, a and b, are composed to form c,
// which calls both methods in order:
c = a + b;
// Remove a from the composed delegate, leaving d,
// which calls only the method Goodbye:
d = c - a;

Console.WriteLine("Invoking delegate a:");
a("A");
Console.WriteLine("Invoking delegate b:");
b("B");
Console.WriteLine("Invoking delegate c:");
c("C");
Console.WriteLine("Invoking delegate d:");
d("D");
}
}