《.NET框架程序设计》第十一章 多事件示例：一个男人和三个女人的故事

第十一章 多事件示例[[/b]一个男人和三个女人的故事[/b]][/b][/b]
[/b]?
摘要：[/b]
?????? 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[/b]：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