说明：  本代码是一个C#开发的即时通讯聊天IM软件，有群，好友列表，上下线通知，P2P语音视频通讯，文件发送功能。但没有做皮肤。代码可以COPY到使用。使用PRTX开发包开发。
(This code is a C# development of instant messaging chat IM software, group, friends list, the offline notification, P2P voice and video communications, file sending capabilities. But did not make the skin. COPY code to use.)