一个男人和三个女人的故事[《.net框架程序设计》_第十一章 多事件示例]

第十一章 多事件示例[一个男人和三个女人的故事]

摘要：

       应用FCL中的System.ComponentModel.EventHandlerList示例一个类型中发布多事件的应用

 

场景：一个男生有三个女朋友，各自有不同的爱好，女朋友A爱好音乐，女朋友B爱好美食，女朋友C爱好XXX，为满足各个女朋友，此男生必须进行唱歌、烹饪食物、xxx。

以此制作程序演示单类型多事件的应用，并假设此男同时只能干一件事情（即排除一边xxx一边唱歌或一边xxx一边烹饪的可能J）

如下为源代码：

using System;

using System.ComponentModel;

 

//男朋友的源代码

public class BoyFriend

{

       protected EventHandlerList eventList

                     = new EventHandlerList();

 

       //

       //满足女朋友A定义音乐喜好

       //使用自定义的音乐事件及回调函数

       protected static readonly object musicEventKey = new object();

       public class MusicEventArgs : EventArgs

       {

              private string strMusicName;

             

              public string MusicName

              {

                     get{

                            return strMusicName;

                     }    

              }

             

              public MusicEventArgs(string strMusicName)

              {

                     this.strMusicName = strMusicName;

              }

       }

      

       public delegate void MusicEventHandler(object sender, MusicEventArgs args);

      

       public event MusicEventHandler MusicMsg

       {

              add

              {

                     eventList.AddHandler(musicEventKey, value);

              }    

              remove

              {

                     eventList.RemoveHandler(musicEventKey, value);

              }

       }

      

       protected virtual void OnMusic(MusicEventArgs e)

       {

              Delegate d = eventList[musicEventKey];

              if(d != null)

              {

                     d.DynamicInvoke(new Object[]{this, e});   

              }

       }

      

       public void SimulateMusic(string strName)

       {

              Console.WriteLine("男朋友：好的，我给你唱支{0}吧！", strName);

              OnMusic(new MusicEventArgs(strName));

      }

     

      //

      //满足女朋友B的美食欲望

      //

      protected static readonly object cateEventKey = new object();

      public class CateEventArgs : EventArgs

      {

             private string strCateName;

             public string CateName

             {

                    get

                    {

                           return strCateName;

                    }    

             }

            

             public CateEventArgs(string strCateName)

             {

                    this.strCateName = strCateName; 

             }

      }

      public delegate void CateEventHandler(Object sender, CateEventArgs args);

      public event CateEventHandler CateMsg

      {

             add

             {

                    eventList.AddHandler(cateEventKey, value);

             }    

            

             remove

             {

                    eventList.RemoveHandler(cateEventKey, value); 

             }

      }

       protected void OnCate(CateEventArgs e)

       {

              Delegate d = eventList[cateEventKey]; 

              if(d != null)

              {

                     d.DynamicInvoke(new Object[]{this, e});   

              }

       }

       public void SimulateCate(string strCateName)

       {

              Console.WriteLine("男朋友：请吃一点我做的{0}", strCateName);

              OnCate(new CateEventArgs(strCateName));

       }

      

       //

       //满足女朋友C的xxx欲望

       //使用EventArgs.Empty事件及System.EventHandler回调函数

       protected static readonly object xxxEventKey = new object();

       public event EventHandler XXXMsg

       {

              add

              {

                     eventList.AddHandler(xxxEventKey, value);

              }    

              remove

              {

                     eventList.RemoveHandler(xxxEventKey, value);  

              }

       }

       protected virtual void OnXXX()

       {

              Delegate d = eventList[xxxEventKey];

              if(d != null)

              {

                     d.DynamicInvoke(new Object[]{this, EventArgs.Empty});

              }

       }

       public void SimulateXXX()

       {

              Console.WriteLine("男朋友：你今天真漂亮呵!");     

              OnXXX();

       }

      

       public static void Main()

       {

              BoyFriend bf = new BoyFriend();

             

              //

              Console.WriteLine("上午 女朋友A来玩：");

              GF_A gfa = new GF_A(bf);

              bf.SimulateMusic("恋曲");

              gfa.Unregister(bf);

             

              //

              Console.WriteLine();

              Console.WriteLine("下午 女朋友B来玩");

              GF_B gfb = new GF_B(bf);

              bf.SimulateCate("祖传小甜点");

              gfb.Unregister(bf);

             

              //

              Console.WriteLine();

              Console.WriteLine("晚上 女朋友C来玩");

              GF_C gfc = new GF_C(bf);

              bf.SimulateXXX();

              gfc.Unregister(bf);

       }

}

 

//女朋友A的源代码

public class GF_A

{

       public GF_A(BoyFriend bf)

       {

              bf.MusicMsg += new BoyFriend.MusicEventHandler(MusicMsg);

              Console.WriteLine("女朋友A：老公!我要听歌");

       }

             

       private void MusicMsg(Object sender, BoyFriend.MusicEventArgs args)

       {

              switch(args.MusicName)

              {

                     case "恋曲":

                     case "清歌":                        

                            Console.WriteLine("女朋友A：哇,是{0}耶，好喜欢啊!", args.MusicName);

                            break;

                     default:

                            Console.WriteLine("女朋友A：这首歌没听过耶,好好听奥!");

                            break;

              }

       }

      

       public void Unregister(BoyFriend bf)

       {

              BoyFriend.MusicEventHandler bfe = new BoyFriend.MusicEventHandler(MusicMsg);

              bf.MusicMsg -= bfe;

              Console.WriteLine("女朋友A: 休息了，别吵！");

       }

}

//女朋友B的源代码

public class GF_B

{

       public GF_B(BoyFriend bf)

       {

              bf.CateMsg += new BoyFriend.CateEventHandler(CateMsg);

              Console.WriteLine("女朋友B: 老公!我饿了！");      

       }

       private void CateMsg(Object sender, BoyFriend.CateEventArgs args)

       {

              switch(args.CateName)

              {

                     case "祖传小甜点":

                            Console.WriteLine("女朋友B: 哇！老公你真能干，{0}好好吃耶！", args.CateName);

                            break;

                     case "饼干":

                     case "方便面":

                            Console.WriteLine("女朋友B: 刚认识你时，给人家做小点心，现在让人家吃方便食品了，555555");

                            break;

                     default:

                            Console.WriteLine("女朋友B: 这是什么东东，没吃过耶");

                            break;

              }    

       }

       public void Unregister(BoyFriend bf)

       {

              BoyFriend.CateEventHandler e = new BoyFriend.CateEventHandler(CateMsg);

              bf.CateMsg -= e;

              Console.WriteLine("女朋友B: 吃饱了，谢谢你噢!");

       }

}

//女朋友C的源代码

public class GF_C

{

       public GF_C(BoyFriend bf)

       {

              bf.XXXMsg += new EventHandler(XXXMsg);

              Console.WriteLine("女朋友C: 老公！你今天真帅哦！");

       }

      

       private void XXXMsg(Object sender, EventArgs args)

       {

              Console.WriteLine("女朋友C: R...O...O...M...");

       }

      

       public void Unregister(BoyFriend bf)

       {

              EventHandler e = new EventHandler(XXXMsg);

              bf.XXXMsg -= e;

              Console.WriteLine("女朋友C：累了，想休息了!");  

       }

}

/*运行结果：

 上午 女朋友A来玩：
女朋友A：老公!我要听歌
男朋友：好的，我给你唱支恋曲吧！
女朋友A：哇,是恋曲耶，好喜欢啊!
女朋友A: 休息了，别吵！

下午 女朋友B来玩
女朋友B: 老公!我饿了！
男朋友：请吃一点我做的祖传小甜点
女朋友B: 哇！老公你真能干，祖传小甜点好好吃耶！
女朋友B: 吃饱了，谢谢你噢!

晚上 女朋友C来玩
女朋友C: 老公！你今天真帅哦！
男朋友：你今天真漂亮呵!
女朋友C: R...O...O...M...
女朋友C：累了，想休息了!

*/

注：1、因上例使用FCL中的System.ComponentModel.EventHandlerList，因此不具备线程安全性。

       2、上述代码中xxx部分未定义事件参数而是使用System.EventArgs.Emtpy，也没有定义回调函数而是使用System.EventHandler;其他两个事件都是自定义的。可以修改其他两个事件

       3、关于发布事件、自定义事件、多事件定义的详细信息，请参考《.net框架程序设计》读书笔记_第十一章 事件