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以前在使用vb来实现多线程的时候，发现有一定的难度。虽然也有这样那样的方法，但都不尽人意，但在c#中，要编写多线程应用程序却相当的简单。这篇文章将作简要的介绍，以起到抛砖引玉的作用！
.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类中幸桓鯰hreadpriority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;
// 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();
}
}
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.
