说明：  使用Udp协议编写的Socket通讯Demo，程序为命令行界面，可以同时启动多个互相发送/接收数据（注意每个实例的本地端口号避免重复，远程端口号写其他实例的本地端口号）。涉及到数据发送接收、多线程、监视器等操作。
(Socket Udp protocol using written communication Demo, procedures for the command-line interface, you can start multiple simultaneous transmit/receive data (note the local port number for each instance to avoid duplication, remote port number to write local port number other instances). Relates to a data transmission and reception, multi-threading, the monitor operation.)