等待異步操作的完成，代碼實現
1 class Program
2 {
3 static void Main(string[] args)
4 {
5 Func<int, int> mySum1 = SumNumbers;
6 Func<int, int> mySum2 = SumNumbers;
7 Func<int, int> mySum3 = SumNumbers;
8
9 AsyncCallback callback = c => Console.WriteLine("線程ID:{0},回調函數執行:{1}",Thread.CurrentThread.ManagedThreadId,c.AsyncState);
10
11
12 IAsyncResult result1= mySum1.BeginInvoke(10000, callback, "第一個異步");
13 IAsyncResult result2= mySum2.BeginInvoke(10000, callback, "第二個異步");
14 IAsyncResult result3= mySum3.BeginInvoke(10000, callback, "第三個異步");
15
16
17 //異步等待方式1：使用EndInvoke
18 int asyc1 = mySum1.EndInvoke(result1);
19 Console.WriteLine("第一個異步已經執行完成，結果:{0}",asyc1);
20
21 //異步等待方式2：使用AsyncWaitHandle.WaitOne，參數-1表示一直等待到執行完成
22 if (result2.AsyncWaitHandle.WaitOne(-1))
23 {
24 Console.WriteLine("第二個異步執行完成");
25 }
26
27 //異步等待方式3：使用IsCompleted判斷
28 while (!result3.IsCompleted)
29 {
30 Console.WriteLine("第三個異步還在執行中....");
31 Thread.Sleep(300);
32 }
33 Console.WriteLine("第三個異步執行完成");
34
35 Console.ReadKey();
36 }
37
38 public static int SumNumbers(int count)
39 {
40 int sum = 0;
41 for (int i = 0; i < count; i++)
42 {
43 sum += i;
44 }
45
46 Thread.Sleep(3000);
47 return sum;
48 }
49 }
代碼執行結果：
