C#--理解线程

时间：2011-05-10 来源：孤独的猫

一个进程可以有一个或多个线程，这些线程共享资源。CPU按照它自己的进度表，在各线程间切换。

线程并不提高计算机在给定时间内可以完成的工作量，但可以使计算机相应更加灵活。在.Net中，用Thread类来创建线程。如：

 1 /*
 2   Example14_1.cs illustrates the creation of threads
 3  */
 4 
 5 using System;
 6 using System.Threading;
 7 
 8 class Example14_1 {
 9 
10    // the Countdown method counts down from 1000 to 1
11    public static void Countdown() {
12     for (int counter = 1000; counter > 0; counter--) {
13       Console.Write(counter.ToString() + " ");
14     }
15   }
16 
17   public static void Main() {
18 
19     // create a second thread
20     Thread t2 = new Thread(new ThreadStart(Countdown));
21 
22       // launch the second thread
23     t2.Start();
24 
25     // and meanwhile call the Countdown method from the first thread
26     Countdown();
27 
28   }
29 
30 }

设置优先级

Thread对象可以定义5个优先级：

Lowest
BelowNormal
Normal
AboveNormal
Highest

用属性Priority类设置：

 1 /*
 2   Example14_2.cs illustrates the use of thread priorities
 3 */
 4 
 5 using System;
 6 using System.Threading;
 7 
 8 class Example14_2 
 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         // set the new thread to highest priority
27         t2.Priority=ThreadPriority.Highest;
28 
29         // Locate the current thread and set it to the lowest priority
30         Thread.CurrentThread.Priority=ThreadPriority.Lowest;
31 
32         // launch the second thread
33         t2.Start();
34 
35         // and meanwhile call the Countdown method from the first thread
36         Countdown();
37 
38     }
39 
40 }