VC++6.0实现QQ聊天功能，本程序采用了异步选择机制在同一个线程中实现了接收端和发送端的功能，避免了采用阻塞套接字由于接收阻塞而导致线程暂停运行的问题。-VC++6.0 achieve QQ chat features, the program uses an asynchronous thread selection mechanism is implemented in the same receiver and transmitter function, avoiding the us