模仿QQ的界面，介绍界面构建的方法和效果，简单易用，便于参考 -just like QQ client, it is easy to use.

CocoaAsyncSocket是一个功能强大、简单易用的异步 socket 通讯（asynchronous socket）类库。支持TCP和UDP两种网络协议。- CocoaAsyncSocket is a powerful, easy to use asynchronous socket communication (asynchronous socket) library. Supports two network protocols TCP and UDP.