一个简单的程序，用了 IAsyncResult 去实现异步操作。 MyWork() 内部通过delegate 调用了非托管的com 组件，但是，当这个程序在[STAThread] 状态下运行时，delegate 死活没有执行，程序进入死循环。
public void Test1()
{
MyWork work = new MyWork();
IAsyncResult ar = work.BeginWork(); //begin the async action
while (!ar.IsCompleted) //<--- this loop will run forever in an WinForm app.
{
//show progress
Thread.Sleep(50);
}
if (ar.IsCompleted)
{
work.EndWork(); // get the result.
}
}
搞了半天，高手指点把Thread.Sleep() 换成 Thread.CurrentThread.Join(50) 就可以了！
虽然MSDN 对两个方法的解释是一样的：
|
Thread.Join Blocks the calling thread until a thread terminates or the specified time elapses. |
|
Thread.Sleep |
但是它们有细微而重要的区别，根据这个BLOG :
Thread.Sleep is a little unusual. We can take control of threads that are inside this service. But, following the tradition of Sleep on the underlying Windows operating system, we perform no pumping.
If you need to Sleep on an STA thread, but you want to perform the standard COM and SendMessage pumping, consider Thread.CurrentThread.Join(timeout) as a replacement.
打印 | 张贴于 2004-08-22 14:31:00 | Tag:vs.net
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