简介：

　　Udp广播消息用在局域网的消息传递很方便。本文使用UdpClient类在WPF下实现Udp广播收发

发送：

1         void MainWindow_Loaded(object sender, RoutedEventArgs e) 2         { 3             Loaded -= MainWindow_Loaded; 4             UdpClient client = new UdpClient(new IPEndPoint(IPAddress.Any, 0)); 5             IPEndPoint endpoint = new IPEndPoint(IPAddress.Parse("255.255.255.255"), 7788);//默认向全世界所有主机发送即可，路由器自动给你过滤，只发给局域网主机 6             String ip = "host:" + Dns.GetHostEntry(Dns.GetHostName()).AddressList.Last().ToString();//对外广播本机的ip地址 7             byte[] ipByte = Encoding.UTF8.GetBytes(ip); 8             DispatcherTimer dt = new DispatcherTimer() { Interval = TimeSpan.FromSeconds(1) };//每隔1秒对外发送一次广播 9             dt.Tick += delegate10             {11                 client.Send(ipByte, ipByte.Length, endpoint);12             };13             dt.Start();14         }

接收：

1         void MainWindow_Loaded(object sender, RoutedEventArgs e) 2         { 3             Loaded -= MainWindow_Loaded; 4             UdpClient client = new UdpClient(new IPEndPoint(IPAddress.Any, 7788));//端口要与发送端相同 5             Thread thread = new Thread(receiveUdpMsg);//用线程接收，避免UI卡住 6             thread.IsBackground = true; 7             thread.Start(client); 8         } 9         void receiveUdpMsg(object obj)10         {11             UdpClient client = obj as UdpClient;12             IPEndPoint endpoint = new IPEndPoint(IPAddress.Any, 0);13             while (true)14             {15                 client.BeginReceive(delegate(IAsyncResult result) {16                     Console.WriteLine(result.AsyncState.ToString());//委托接收消息17                 }, Encoding.UTF8.GetString(client.Receive(ref endpoint)));18             }19         }

效果：