c#委托与事件2

首先是一个关机器的一般方法：

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Text;
 5 
 6 namespace DelegateDemo
 7 {
 8     class Program
 9     {
10         static void Main(string[] args)
11         {
12             FoldingMachine folder = new FoldingMachine();
13             WeldingMachine welder = new WeldingMachine();
14             PaintingMachine painter = new PaintingMachine();
15 
16             Controller controller = new Controller();
17             controller.Folder = folder;
18             controller.Welder = welder;
19             controller.Painter = painter;
20             controller.ShutDown();
21             Console.ReadKey();
22         }
23     }
24 }
Program.cs
 1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Text;
 5 
 6 namespace DelegateDemo
 7 {
 8     class Controller
 9     {
10         private FoldingMachine folder;
11         private WeldingMachine welder;
12         private PaintingMachine painter;
13         public void ShutDown()
14         {
15             folder.FinishFolding();
16             welder.FinishWelding();
17             painter.PaintOff();
18         }
19         public FoldingMachine Folder
20         {
21             set { this.folder = value; }
22         }
23 
24         public WeldingMachine Welder
25         {
26             set { this.welder = value; }
27         }
28 
29         public PaintingMachine Painter
30         {
31             set { this.painter = value; }
32         }
33 
34     }
35 }
Controller.cs
 1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Text;
 5 
 6 namespace DelegateDemo
 7 {
 8     class FoldingMachine
 9     {
10         public void StopFolding(int ShutDownTime)
11         {
12             Console.WriteLine("stop FoldingMachine");
13         }
14 
15         public void FinishFolding()
16         {
17             StopFolding(0);
18         }
19     }
20 }
FoldingMachine.cs
 1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Text;
 5 
 6 namespace DelegateDemo
 7 {
 8     class PaintingMachine
 9     {
10         public void PaintOff()
11         {
12             Console.WriteLine("stop PaintingMachine");
13         }
14     }
15 }
PaintingMachine.cs
 1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Text;
 5 
 6 namespace DelegateDemo
 7 {
 8     class WeldingMachine
 9     {
10         public void FinishWelding()
11         {
12             Console.WriteLine("stop WeldingMachine.");
13         }
14     }
15 }
WeldingMachine.cs

 

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Text;
 5 
 6 namespace DelegateDemo
 7 {
 8     class Program
 9     {
10         static void Main(string[] args)
11         {
12             FoldingMachine folder = new FoldingMachine();
13             WeldingMachine welder = new WeldingMachine();
14             PaintingMachine painter = new PaintingMachine();
15 
16             Controller controller = new Controller();
17             controller.Folder = folder;
18             controller.Welder = welder;
19             controller.Painter = painter;
20             controller.ShutDown();
21             controller.StopManchinery();
22             Console.ReadKey();
23         }
24     }
25 }
Program.cs
 1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Text;
 5 
 6 namespace DelegateDemo
 7 {
 8     class Controller
 9     {
10         private FoldingMachine folder;
11         private WeldingMachine welder;
12         private PaintingMachine painter;
13         public delegate void  stopManchineryDelegate();
14         stopManchineryDelegate stopManchinery;
15 
16         public Controller()
17 
18         {
19 
20             //
21         }
22         public stopManchineryDelegate StopManchinery
23         {
24             get { return stopManchinery; }
25             set { stopManchinery += value; }
26         }
27          public void SetStopManchinery()
28         {
29             //stopManchinery = new stopManchineryDelegate(folder.StopFolding);
30             stopManchinery += folder.StopFolding;
31             stopManchinery += welder.FinishWelding;
32             stopManchinery += painter.PaintOff;
33 
34         }
35         public void ShutDown()
36         {
37             //folder.FinishFolding();
38             //welder.FinishWelding();
39             //painter.PaintOff();
40             SetStopManchinery();
41         }
42         public FoldingMachine Folder
43         {
44             set { this.folder = value; }
45         }
46 
47         public WeldingMachine Welder
48         {
49             set { this.welder = value; }
50         }
51 
52         public PaintingMachine Painter
53         {
54             set { this.painter = value; }
55         }
56 
57     }
58 }
Controller.cs
 1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Text;
 5 
 6 namespace DelegateDemo
 7 {
 8     class FoldingMachine
 9     {
10         public void StopFolding()
11         {
12             Console.WriteLine("stop FoldingMachine");
13         }
14 
15         public void FinishFolding()
16         {
17             StopFolding();
18         }
19     }
20 }
FoldingMachine
 1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Text;
 5 
 6 namespace DelegateDemo
 7 {
 8     class PaintingMachine
 9     {
10         public void PaintOff()
11         {
12             Console.WriteLine("stop PaintingMachine");
13         }
14     }
15 }
PaintingMachine
 1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Text;
 5 
 6 namespace DelegateDemo
 7 {
 8     class WeldingMachine
 9     {
10         public void FinishWelding()
11         {
12             Console.WriteLine("stop WeldingMachine.");
13         }
14     }
15 }
WeldingMachine.cs

注意委托（其实就是指针，指向函数的指针，也就是函数指针）的参数要与所指向的函数的参数相同，体现到代码中就是FoldingMachine.cs中的修改。另外一个类中的字段即使是public也不能在另一个类中直接使用，所以代码中使用了方法（controller.StopManchinery();）来使用另一个类中的委托。

lamada表达式：

事件：

 

事件的调用只能在定义事件的类的内部调用，无论是用public还是private修饰事件。委托违反了封装的原则，事件封装委托，保证了封装。

参考：http://blog.csdn.net/jamestaosh/article/details/4372172

要创建一个事件驱动的程序需要下面的步骤：

1.         声明关于事件的委托；

2.         声明事件；

3.         编写触发事件的函数；

4.         创建事件处理程序；

5.         注册事件处理程序；

6.         在适当的条件下触发事件。 

现在我们来编写一个自定义事件的程序。主人养了一条忠实的看门狗，晚上主人睡觉的时候，狗负责看守房子。一旦有小偷进来，狗就发出一个Alarm事件，主人接到Alarm事件后就会采取相应的行动。假设小偷于2009年元旦午夜时分到达。

//事件发送者

class Dog
{
    //1.声明关于事件的委托；
    public delegate void AlarmEventHandler(object sender, EventArgs e);

    //2.声明事件；   
    public event AlarmEventHandler Alarm;

    //3.编写引发事件的函数；
    public void OnAlarm()
    {
        if (this.Alarm != null)
        {
            Console.WriteLine("/n狗报警: 有小偷进来了,汪汪~~~~~~~");
            this.Alarm(this, new EventArgs());   //发出警报
         }
    }
}

//事件接收者
class Host
{
    //４.编写事件处理程序
    void HostHandleAlarm(object sender, EventArgs e)
    {
        Console.WriteLine("主  人: 抓住了小偷！");
    }

    //５.注册事件处理程序
    public Host(Dog dog)
    {
        dog.Alarm += new Dog.AlarmEventHandler(HostHandleAlarm);
    }
}

//６.现在来触发事件
class Program
{
    static void Main(string[] args)
    {
        Dog dog = new Dog();
        Host host = new Host(dog);

        //当前时间，从2008年12月31日23:59:50开始计时
        DateTime now = new DateTime(2008, 12, 31, 23, 59, 50);
        DateTime midnight = new DateTime(2009, 1, 1, 0, 0, 0);

        //等待午夜的到来
        Console.WriteLine("时间一秒一秒地流逝... ");
        while (now < midnight)
        {
            Console.WriteLine("当前时间: " + now);
            System.Threading.Thread.Sleep(1000);   //程序暂停一秒
            now = now.AddSeconds(1);                //时间增加一秒
         }

        //午夜零点小偷到达,看门狗引发Alarm事件
        Console.WriteLine("/n月黑风高的午夜: " + now);
        Console.WriteLine("小偷悄悄地摸进了主人的屋内... ");
        dog.OnAlarm();
    }
} 

http://blog.csdn.net/Wiiix/article/details/51463977

下面再看一个例子:

在我们创建一个事件之前，我们需要一个委托，而一般标准的委托声明如下:

    public delegate void EventHandler(object sender, System.EventArgs e);

第一个形参object sender定义了对象来源，第二个形参放的是继承自System.EventArgs的类，一般上这个类包含了事件的详细信息。

例子:

    class ButtonEventArgs:EventArgs

    {

        public string time;

}

在这里我们不需要传递什么事件信息，所以我们用基类EventArgs就好。

 1  public delegate void EventHandler(object sender, System.EventArgs e);
 2 
 3     class Publisher
 4     {
 5         public event EventHandler Added; //定义发生事件
 6 
 7 
 8         protected virtual void OnAdded(System.EventArgs e) //当事件发生中触发方法
 9         {
10             if(Added!=null)
11             {
12                 Added(this, e);
13             }
14         }
15         public void Add(object value) //触发事件的方法
16         {
17    
18             OnAdded(System.EventArgs.Empty);
19         }
20 }
21 
22 
23 
24     class Subscriber
25     {
26         void AddedEventHandler(object sender,System.EventArgs e)
27         {
28             System.Console.WriteLine("AddEvent occured");
29         }
30         
31         static void Main()
32         {
33             Subscriber s = new Subscriber();
34             Publisher p = new Publisher();
35             p.Added += s.AddedEventHandler;
36 p.Add(10);
37         }
38 }
View Code

事件的使用步骤如下:

存放事件的类

1.定义事件

2.触发事件的方法(protected)

3.间接触发事件的方法(public)

触发事件的类

1.定义方法

2.注册方法

3.触发方法

 
http://www.cnblogs.com/yinqixin/p/5067033.html 


 1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Text;
 5 
 6 namespace 自定义事件一
 7 {
 8     class Program
 9     {
10         static void Main(string[] args)
11         {
12             Dog dog = new Dog();
13             Host host = new Host(dog );
14             DateTime now = new DateTime(2011, 12, 31, 23, 59, 55);
15             DateTime midnight = new DateTime(2012, 1, 1, 0, 0, 0);
16             while (now < midnight)
17             {
18                 Console.WriteLine("当前时间" + now);
19                 System.Threading.Thread.Sleep(1000);
20                 now = now.AddSeconds(1);
21             }
22             Console.WriteLine("
月黑风高的午夜：" + now);
23             Console.WriteLine("小偷进了主人的屋内...........");
24             dog.OnAlarm();
25             Console.ReadKey();
26         }
27     }
28     class Dog
29     {
30         //第一：声明关于事件的委托
31         public delegate void AlarmEventHandler(object sender, EventArgs e);
32         //第二：声明事件
33         public event AlarmEventHandler Alarm;//前面的public没用，这个Alarm事件仍然是private的，可以在类外绑定方法，不能运行这个事件
34         //第三：编写引发shijian的函数
35         public void OnAlarm()
36         {
37             if (this.Alarm != null)
38             {
39                 Console.WriteLine("
狗报警，有小偷进来了，汪汪汪~~~");
40                 this.Alarm(this, new EventArgs());//运行这个事件；this 当前对象，this.Alarm是当前对象多引用的事件
41             }
42         }
43     }
44     class Host
45     {
46         //第四：编写事件的处理程序
47         void HostHandeAlarm(object sender, EventArgs e)
48         {
49             Console.WriteLine("主人：抓住了小偷！~");
50         }
51         //第五：注册事件的处理程序
52         public Host(Dog dog)
53         {
54             dog.Alarm  += new Dog.AlarmEventHandler(HostHandeAlarm);
55         }
56     }
57 
58 }



 





        

	      

	    

	  

	  

	    
      
        【推广】
        免费学中医，健康全家人
      
	  

    

    

          原文地址：https://www.cnblogs.com/zhubinglong/p/8167972.html