每次用到委拖（代理）都有点晕，今天把汇总一下，方便后面回顾。

       一 、delegate、 Action(Fun)          //委托是一个类型，继承自System.MulticastDelegate        声明委托         public delegate void NoReturnNoPara();      //无参无返回值         public delegate void NoReturnWithPara(string name);//有参无返回值         public delegate int WithReturnNoPara();      //无参有回值

         public void Show()         {                  //把方法包裹到变量里面去，变量invoke可以调用方法  把方法当成了一个变量                  NoReturnNoPara method1 = new NoReturnNoPara(this.DoNothing);//2 委托实例化                 method1.Invoke();    //3 委托实例的调用1                 method1();    //3 委托实例的调用2                 this.DoNothing();                 NoReturnWithPara method2 =  new NoReturnWithPara(this.DoNothingWithPara);                 method2("hello");         }

       private void DoNothing()         {             Console.WriteLine("这里是DoNothing");         }

        private void DoNothingWithPara(string name)         {             Console.WriteLine(name);         }

       private int  ReturnStr(String name)        {   String newName ="名子:"+name;             return newName;        }

2 Action(无反返)、Fun(有返回） Action 是将Delegate 的类型定义和实例化省去了，简化了代码(官方https://docs.microsoft.com/en-us/dotnet/api/system.action-1?redirectedfrom=MSDN&view=net-5.0) 上面的两个方法使用就简化了 public void Show()  {       Action method1= DoNothing; //无参数      method1();      Action method2 =DoNothingWithPara;      method2("Hello");      Fun  method3  =  returnStr；//带1个参数,返回值。      String newName= method3("liLei");  }

二、匿名方法、 Lambda        这两个是简化了 方法的定义。    3 匿名方法

       public delegate void NoReturnNoPara();      //无参无返回值         public delegate void NoReturnWithPara(string name);//有参无返回值         public delegate int WithReturnNoPara();      //无参有回值        public void Show()         {                  NoReturnNoPara method1 = delegate() {Console.WriteLine("这里是DoNothing");};                //DoNothing() 这个方法直接移到Show方法里面，DoNothing()方法相当于被隐藏了。                  method1();                  NoReturnWithPara method2 = delegate( name){Console.WriteLine(name);};                  method2("Hello");                  ReturnStr method3 =delegate(name){String newName ="名子:"+name;return newName;};                  String newName= method3("lilei");         }       4 Lambda方法       public void Show()         {                  NoReturnNoPara method1 =() =>Console.WriteLine("这里是DoNothing");                   method1();                  NoReturnWithPara method2 = ( name)=>Console.WriteLine(name);                  method2("liLei"）;                  ReturnStr method3=(name) =>{String newName ="名子:"+name;return newName;};         }     5，进一步简化 Action+lambda，简去委托定义和方法嵌入

     public void Show()         {                  Action method1 =() =>Console.WriteLine("这里是DoNothing");                   method1();                 Action method2 = ( name)=>Console.WriteLine(name);                  method2();                  Fun  method2 = ( name)=>{String newName ="名子:"+name;return newName;};                  String newName=method2("liLei"）;         }      这么一理，还是比清楚了。