public MainForm() { InitializeComponent(); try { foreach (IPAddress ip in Dns.GetHostEntry(Dns.GetHostName()).AddressList) { if (ip.AddressFamily == System.Net.Sockets.AddressFamily.InterNetwork) { localIP = ip; break; } } udpListen = new UDPListen(new IPEndPoint(localIP, localPort)); System.Threading.ThreadStart threadStartListen; threadStartListen = new System.Threading.ThreadStart(udpListen.open); udpListen.msgReceiptEvent += new msgReceiptHandler(listen_msgReceiptEvent); threadListen = new System.Threading.Thread(threadStartListen); threadListen.Start(); } catch (Exception ex) { MessageBox.Show(ex.Message); } }