C#中Udp广播的发送与接收(UdpClient)

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 += delegate
10             {
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：