QQ程序，使用MVC架构实现客户端与服务器端，具有的功能：聊天，添加好友，删除好友，显示好友列表，文件传输，给好友留言，查看聊天记录-QQ program, using the MVC architecture to achieve client and server side, with features: chat, add friends, delete friends, show your friends list, file transfer, to a Friend messages