1         public class Publish
 2         {
 3             public delegate void PublishEventHandler(object sender,PublishEventArgs e);
 4             private event PublishEventHandler publish;
 5             private Delegate[] del;
 6             public class PublishEventArgs :EventArgs
 7             {
 
 8                 public string BookName { get; private set; }
 9                 public PublishEventArgs(string bookName)
10                 {
11                     this.BookName = bookName;
12                 }
13             }
14 
15             public void RegisterPublish(PublishEventHandler publish)
 
16             {
17                 this.publish += publish;
18             }
19             public void UnRegisterPublish(PublishEventHandler publish)
20             {
21                 this.publish -= publish;
22             }
23 
24             public void OnPublish(PublishEventArgs e)
25             {
 
26                 Console.WriteLine("OnDoPublish");
27                 if(publish != null)
28                     publish(this,e);
29             }
30 
31             public void OnPublishAsyn(PublishEventArgs e)
32             {
33                 Console.WriteLine("OnDoPublish");
34                 if(publish != null) {
35                     del = publish.GetInvocationList();
36                     foreach(Delegate item in del) {
37                         PublishEventHandler Method = (PublishEventHandler)item;
38                         Method.BeginInvoke(null,e,null,null);
39                     }
40                 }
41             }
42         }

 1       public class SubScriber
 2         {
 3             private string OrderName;
 4             public SubScriber(string orderName)
 5             {
 6                 this.OrderName = orderName;
 7             }
 8 
 9             public void publish(object sender,Test.Program.Publish.PublishEventArgs e)
10             {
11                 Console.WriteLine(OrderName + " Buy " + e.BookName
12                     + " " + Thread.CurrentThread.ManagedThreadId);
13                  Thread.Sleep(2000);
14             }
15         }

 1         static void Main(string[] args)
 2         {
 3             Publish pub = new Publish();
 4             SubScriber sub1 = new SubScriber("xiao zeng");
 5             SubScriber sub2 = new SubScriber("xiao Li");
 6             SubScriber sub3 = new SubScriber("xiao Wang");
 7             SubScriber sub4 = new SubScriber("xiao zhao");
 8             pub.RegisterPublish(sub1.publish);
 9             pub.RegisterPublish(sub2.publish);
10             pub.RegisterPublish(sub3.publish);
11             pub.RegisterPublish(sub4.publish);
12             pub.OnPublish(new Publish.PublishEventArgs("Tom And Jerry"));
13             pub.OnPublishAsyn(new Publish.PublishEventArgs("Tom And Jerry"));
14             Console.ReadLine();
15         }

C# 委托事件的異步調用