c# 委托与事件

一。委托：

1.定义委托 public delegate void MyDelegate(string msg);

2.定义函数 这里委托相当于一个函数指针

public static void Func(string msg)

{

Console.WriteLine(msg);

}

3.创建实例并调用

MyDelegate md = new MyDelegate(Func);

md("fuck");

完整代码（不包括using部分）

namespace EventAndDelegate

{

public delegate void MyDelegate(string msg);

class Program

{

static void Main(string[] args)

{

MyDelegate md = new MyDelegate(Func);

md("fuck");

Console.ReadKey();

}

public static void Func(string msg)

{

Console.WriteLine(msg);

}

}

}

二。事件

1.定义事件 Timer myTimer = new Timer(100);

2.添加函数到事件队列(注意添加的函数参数固定)

myTimer.Elapsed += new ElapsedEventHandler(WriteChar);



static void WriteChar(object source, ElapsedEventArgs e)

{

Console.Write(DisplayString[counter++ % DisplayString.Length]);

}

3.开始事件 myTimer.Start();

三。编写自己的事件，与委托结合

1.定义事件类

namespace EventAndDelegate

{

public delegate void DelHandler(string msg);

class MyEvent

{

Timer myTimer;

public event DelHandler MyEv;

public MyEvent()

{

myTimer = new Timer(100);

myTimer.Elapsed += EventFunc;

}

public void Connect()

{

myTimer.Start();

}

public void DisConnect()

{

myTimer.Stop();

}

private void EventFunc(object sender, EventArgs e)

{

Console.WriteLine("Here comes message!");

Random rad = new Random();

if (rad.Next(5) == 0 && MyEv != null)

{

MyEv("Fuck,finally turns to me !");

}

}

}

}

2.定义事件执行函数类

namespace EventAndDelegate

{

class MyEventFunc

{

public void Fucn(string msg)

{

Console.WriteLine("I say:" + msg);

}

}

}

3.主类中实现

namespace EventAndDelegate

{

public delegate void MyDelegate(string msg);

class Program

{

static void Main(string[] args)

{

MyEvent me = new MyEvent();

MyEventFunc mef = new MyEventFunc();

me.MyEv += new DelHandler(mef.Fucn);

me.Connect();

Console.ReadKey();

}

}

}