一个可以用VC的多线程管理的线程池类，类似Java类库的线程池。内有一个Demo程序，帮助初学者理解和使用该封装好的类。-A VC can be multi-threaded managed thread pool class, similar to the Java class library for the thread pool. There is a Demo program to help beginners to understand and use the packaged cla