说明：  qt界面编程是相关知识，开发出一套网络通讯系统，该系统由服务端和客户端两部分组成，服务端对客户端发送消息进行判断，转发等操作，从而使各个客户端之间能够进行信息的交互，客户端主要负责客户的登录，显示在线客户列表，以及各个客户之间进行信息的交互。
(qt programming interface is relevant knowledge, develop a network communication system, the system consists of server and client in two parts, the server sends messages to the client to make judgments, forwarding and other operations, so that each client can be performed between the information exchange, the client is responsible client' s login, show online customer list, as well as various information exchange between customers.)