[C#]實作UDP Broadcast的傳送與接收

	private static void BroadcastMessage(byte[] message, int port)
	{
		using (var sock = new Socket(AddressFamily.InterNetwork, SocketType.Dgram,
		 ProtocolType.Udp))
		{
			sock.EnableBroadcast = true;
			sock.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.Broadcast, true);

			var iep = new IPEndPoint(IPAddress.Broadcast, port);

			sock.SendTo(message, iep);
		}
	}</pre></div>

	private void ReceiveBroadcastMessage(Action<EndPoint, byte[]> receivedAction, int port)
	{
		using (var sock = new Socket(AddressFamily.InterNetwork,

SocketType.Dgram, ProtocolType.Udp)) { var ep = new IPEndPoint(IPAddress.Any, port) as EndPoint; sock.Bind(ep);

			while (true)
			{
				var buffer = new byte[1024];
				var recv = sock.ReceiveFrom(buffer, ref ep);

				var data = new byte[recv];

				Array.Copy(buffer, 0, data, 0, recv);

				receivedAction(ep, data);

				Thread.Sleep(500);
				Application.DoEvents();
			}
		}
	}</pre></div>

namespace WindowsFormsApplication8 { public partial class Form1 : Form { public Form1() { InitializeComponent(); }

	private void button1_Click(object sender, EventArgs e)
	{
		BroadcastMessage("This is a test message", 9051);
	}

	private void Form1_Load(object sender, EventArgs e)
	{
		backgroundWorker1.RunWorkerAsync();
	}

	private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
	{
		ReceiveBroadcastMessage((EndPoint ep, string data) =>
		{
			this.Invoke((MethodInvoker)delegate()
			{
				listBox1.Items.Add(string.Format("received: {0} from: {1}",
						   data, ep.ToString()));
			});
		}, 9051);
	}

	private static void BroadcastMessage(string message, int port)
	{
		BroadcastMessage(Encoding.ASCII.GetBytes(message), port);
	}

	private static void BroadcastMessage(byte[] message, int port)
	{
		using (var sock = new Socket(AddressFamily.InterNetwork, SocketType.Dgram,
		 ProtocolType.Udp))
		{
			sock.EnableBroadcast = true;
			sock.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.Broadcast, true);

			var iep = new IPEndPoint(IPAddress.Broadcast, port);

			sock.SendTo(message, iep);
		}
	}

	private void ReceiveBroadcastMessage(Action<EndPoint, string> receivedAction, int port)
	{
		ReceiveBroadcastMessage((ep, data) =>
		{
			var stringData = Encoding.ASCII.GetString(data);
			receivedAction(ep, stringData);
		}, port);
	}

	private void ReceiveBroadcastMessage(Action<EndPoint, byte[]> receivedAction, int port)
	{
		using (var sock = new Socket(AddressFamily.InterNetwork,

SocketType.Dgram, ProtocolType.Udp)) { var ep = new IPEndPoint(IPAddress.Any, port) as EndPoint; sock.Bind(ep);

			while (true)
			{
				var buffer = new byte[1024];
				var recv = sock.ReceiveFrom(buffer, ref ep);

				var data = new byte[recv];

				Array.Copy(buffer, 0, data, 0, recv);

				receivedAction(ep, data);

				Thread.Sleep(500);
				Application.DoEvents();
			}
		}
	}
}

}

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