通过3个关于线程的编程，由易到难，可以了解线程是如何被创建，挂起，执行，以及如何去添加一个功能函数来实现线程的特定功能-Through 3 on the thread of programming, from easy to difficult, to understand how the thread is created, hang, execution, and how to add a feature function to achieve specific functions thre