线程退出时，其拥有的窗口资源也会被释放掉。

http://msdn.microsoft.com/en-us/library/ms686724(v=vs.85).aspx

 

 

Terminating a thread has the following results:

Any resources owned by the thread, such as windows and hooks, are freed.The thread exit code is set.The thread object is signaled.If the thread is the only active thread in the process, the process is terminated. For more information, see Terminating a Process.