C#--使用Timer类和Join方法管理线程

时间：2011-05-11 来源：孤独的猫

Timer类允许将"fire-and-forget"线程添加到用户程序。在实例化Timer对象时，需要指定以下4个参数

callback　　提供Timer将调用方法的TimerCallback委托
state　　应该传递给TimerCallback方法的对象。这个参数可为null
dueTime　　Timer首次激发之前延迟的毫秒数
Period　　Timer调用之间的毫秒数。

以下为Timer的一个示例：

 1 /*
 2   Example14_5.cs illustrates the use of the Timer class
 3  */
 4 
 5  using System;
 6  using System.Threading;
 7 
 8 class Example14_5 
 9 {
10 
11     // the CheckTime method is called by the Timer
12     public static void CheckTime(Object state) 
13     {
14         Console.WriteLine(DateTime.Now);
15     }
16 
17     public static void Main() 
18     {
19 
20         // create the delegate that the Timer will call
21         TimerCallback tc = new TimerCallback(CheckTime);
22 
23         // create a Timer that runs twice a second, starting in one second
24         Timer t = new Timer(tc, null, 1000, 500);
25 
26         // Wait for user input
27         Console.WriteLine("Press Enter to exit");
28         int i = Console.Read();
29 
30         // clean up the resources
31         t.Dispose();
32         t = null;
33 
34     }
35 
36 }

Thread.Join方法允许“持有” 某个线程，直至另一个线程完成其工作。如：

 1 /*
 2   Example14_6.cs shows the Thread.Join method in action
 3 */
 4 
 5 using System;
 6 using System.Threading;
 7 
 8 class Example14_6 
 9 {
10 
11     // the Countdown method counts down from 1000 to 1
12     public static void Countdown() 
13     {
14         for (int counter = 1000; counter > 0; counter--) 
15         {
16             Console.Write(counter.ToString() + " ");
17         }
18     }
19 
20     public static void Main() 
21     {
22 
23         // create a second thread
24         Thread t2 = new Thread(new ThreadStart(Countdown));
25 
26         // launch the second thread
27         t2.Start();
28 
29         // block the first thread until the second is done
30         t2.Join();
31 
32         // and  call the Countdown method from the first thread
33         Countdown();
34 
35     }
36 
37 }