C# 委托的使用（指向函数的指针）

using System;namespace ConsoleApplication19{    class Program //so easy    {        public delegate void Del(string message);        public static void DelegateMethod(string message)        {            Console.WriteLine(message);        }        public static void MethodWithCallback(int param1, int param2, Del callback)        {            callback("The number is: " + (param1 + param2).ToString());        }        static void Main(string[] args)        {            // Instantiate the delegate.            Del handler = DelegateMethod;            // Call the delegate.            //handler("Hello World");            MethodWithCallback(1, 2, handler);        }    }}