委托是一个类，它定义了方法的类型，使得可以将方法转换成另一个方法的参数类进行传递，这种将方法动态给参数赋值的方法。可以再程序中避免大量使用（IF-ELSE、SWITCH）,同时使得程序具有更好的扩展性。

winform下例程：

C#学习之路--线程与委托_Threading

GreetingManager文件如下：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;


namespace DelegateLearn
{
    //class GreetingManager
    //{

    //}

    //在GreetingManager类的内部声明Delegate1变量
    

    //定义委托，它定义了可以代表的方法的类型
    public delegate void GreetingDelegate(string name);
    //新建的greetingmanager类
    public class GreetingManager{
    public GreetingDelegate delegate1; 
        public void GreetPeople(string name,GreetingDelegate MakeGreeting)
        {
            MakeGreeting(name);
        }
    }
    //class Program{

    //}
}


Form1.cs文件如下：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using DelegateLearn;

namespace DelegateLearn
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        private static void ChineseGreeting(string name)
        {
            Console.WriteLine("早上好," + name);
        }
        private static void EnglishGreeting(string name)
        {
            Console.WriteLine("Morning," + name);
        }
        private void button1_Click(object sender, EventArgs e)
        {
            GreetingManager gm = new GreetingManager();
            //gm.GreetPeople("ThreeS Zhao", EnglishGreeting);
            //gm.GreetPeople("赵", ChineseGreeting);

            gm.delegate1 = EnglishGreeting;
            gm.delegate1 += ChineseGreeting;


            //GreetingDelegate delegate1;
            //delegate1 = EnglishGreeting;
            //delegate1 += ChineseGreeting;

            gm.GreetPeople("ThreeS",gm.delegate1);
        }
    }
}

输出测试：


C#学习之路--线程与委托_C#_02