UDP通信小例子

服务端

private void FormChat_Load(object sender, EventArgs e)
    {
        //创建接收线程
        Thread RecivceThread = new Thread(RecivceMsg);
        RecivceThread.IsBackground = true;
        RecivceThread.Start();
        sendText.Focus();
    }

    private void RecivceMsg()
    {
        IPEndPoint local = new IPEndPoint(ip,portRecv);
        RecviceClient = new UdpClient(local);

        IPEndPoint remote = new IPEndPoint(IPAddress.Any, portSend);
        while (true)
        {
            try
            {
                byte[] recivcedata =  RecviceClient.Receive(ref remote);
                string strMsg = Encoding.ASCII.GetString(recivcedata, 0, recivcedata.Length);
                AddItem(listBoxRecv, string.Format("来自{0}：{1}", remote, strMsg));
            }
            catch
            {
                break;
            }
        }
    }

客户端

private void btnSend_Click(object sender, EventArgs e)
    {
        Thread t = new Thread(SendMsg);
        t.IsBackground = true;
        t.Start(sendText.Text);
       
    }

    private void SendMsg( object obj )
    {
        string message = (string)obj;
        SendClient = new UdpClient(0);
        byte[] bytes = System.Text.Encoding.UTF8.GetBytes(message);
        remoteIp = IPAddress.Parse(remoteIPBox.Text);
        IPEndPoint iep = new IPEndPoint(remoteIp,portSend);
        try
        {
            SendClient.Send(bytes, bytes.Length, iep);
            AddItem(listBoxstatus, string.Format("向{0}发送：{1}", iep, message));  //异步委托显示数据
            clearTextBox();
        }
        catch(Exception ex)
        {
            AddItem(listBoxstatus,"发送出错"+ex.Message);
        }
    }