说明：  MFC网络编程，多线程开发实例，使用多线程事务模式，搭建多人聊天室，实现消息的及时响应，多个用户可以随时加入聊天。
(MFC network programming, multi-threaded development examples, the use of multi-threaded transaction mode, build a multi-user chat room, timely response to messages, multiple users can join chat at any time.)