一个结合了mfc/winsock/多线程等技术实现的聊天程序，只有聊天功能，但是用于广泛，主要适用了tcp链接，udp打洞技术.-A combination of mfc/winsock/multi-threading technology to achieve a chat program, and only chat, but for a wide range, mainly applicable to the tcp link, udp holes technology.