用VisualC＃实现UDP协议，最为常用，也是最为关键的类就是UdpClient，UdpClient位于命名空间System.Net.Sockets中，VisualC＃发送、接收UDP数据包都是通过UdpClient类的(The realization of UDP protocol with VisualC, the most commonly used, but also the key is UdpClient, UdpClient is located in the namespace