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);
        }

    }
}