C#中编写多线程

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.NET将关于多线程的功能定义在System.Threading名字空间中。因此，要使用多线程，必须先声明引用此名字空间（using System.Threading;）。
       即使你没有编写多线程应用程序的经验，也可能听说过“启动线程”“杀死线程”这些词，其实除了这两个外，涉及多线程方面的还有诸如“暂停线程”“优先级”“挂起线程”“恢复线程”等等。下面将一个一个的解释。
    a.启动线程
    顾名思义，“启动线程”就是新建并启动一个线程的意思，如下代码可实现：
    Thread thread1 = new Thread(new ThreadStart( Count));
    其中的 Count 是将要被新线程执行的函数。
    b.杀死线程
    “杀死线程”就是将一线程斩草除根，为了不白费力气，在杀死一个线程前最好先判断它是否还活着（通过 IsAlive 属性），然后就可以调用 Abort 方法来杀死此线程。
    c.暂停线程
    它的意思就是让一个正在运行的线程休眠一段时间。如 thread.Sleep(1000); 就是让线程休眠1秒钟。
    d.优先级
    这个用不着解释了。Thread类中有一个ThreadPriority属性，它用来设置优先级，但不能保证操作系统会接受该优先级。一个线程的优先级可 分为5种：Normal, AboveNormal, BelowNormal, Highest, Lowest。具体实现例子如下:
    thread.Priority = ThreadPriority.Highest;
    e.挂起线程
    Thread类的Suspend方法用来挂起线程，知道调用Resume，此线程才可以继续执行。如果线程已经挂起，那就不会起作用。
    if (thread.ThreadState = ThreadState.Running)
    {
         thread.Suspend();
    }
    f.恢复线程
    用来恢复已经挂起的线程，以让它继续执行，如果线程没挂起，也不会起作用。
    if (thread.ThreadState = ThreadState.Suspended)
    {
         thread.Resume();
    }
    下面将列出一个例子，以说明简单的线程处理功能。此例子来自于帮助文档。
using System;
    using System.Threading;

   
       此代码产生的输出类似如下内容：

    Main thread: Start a second thread.
    Main thread: Do some work.
    ThreadProc: 0
    Main thread: Do some work.
    ThreadProc: 1
    Main thread: Do some work.
    ThreadProc: 2
    Main thread: Do some work.
    ThreadProc: 3
    Main thread: Call Join(), to wait until ThreadProc ends.
    ThreadProc: 4
    ThreadProc: 5
    ThreadProc: 6
    ThreadProc: 7
    ThreadProc: 8
    ThreadProc: 9
    Main thread: ThreadProc.Join has returned.  Press Enter to end program.

    // Simple threading scenario:  Start a static method running
    // on a second thread.
    public class ThreadExample {
        // The ThreadProc method is called when the thread starts.
        // It loops ten times, writing to the console and yielding
        // the rest of its time slice each time, and then ends.
        public static void ThreadProc() {
            for (int i = 0; i < 10; i++) {
                Console.WriteLine("ThreadProc: {0}", i);
                // Yield the rest of the time slice.
                Thread.Sleep(0);
            }
        }
   
        public static void Main() {
            Console.WriteLine("Main thread: Start a second thread.");
            // The constructor for the Thread class requires a ThreadStart
            // delegate that represents the method to be executed on the
            // thread.  C# simplifies the creation of this delegate.
            Thread t = new Thread(new ThreadStart(ThreadProc));
            // Start ThreadProc.  On a uniprocessor, the thread does not get
            // any processor time until the main thread yields.  Uncomment
            // the Thread.Sleep that follows t.Start() to see the difference.
            t.Start();
            //Thread.Sleep(0);
   
            for (int i = 0; i < 4; i++) {
                Console.WriteLine("Main thread: Do some work.");
                Thread.Sleep(0);
            }
   
            Console.WriteLine("Main thread: Call Join(), to wait until ThreadProc ends.");
            t.Join();
            Console.WriteLine("Main thread: ThreadProc.Join has returned.  Press Enter to end program.");
            Console.ReadLine();
        }
    }