一个完整的文字聊天，视频/语音传输，电子白板，共享文件的使用RTC技术编写的程序。（使用前请下载RTC CLIENT SDK API，现在最新版是1。3，大家可以在微软的网站上下载）-a complete text chat, video / voice transmission, electronic whiteboards, shared use of the RTC technical preparation process. (Download the use of the former