var client = new TcpClient();var result = client.BeginConnect("remotehost", this.Port, null, null);var success = result.AsyncWaitHandle.WaitOne(TimeSpan.FromSeconds(1));if (!success){ throw new Exception("Failed to connect.");}// we have connectedclient.EndConnect(result);

.Net 4.5的简便写法

var client = new TcpClient();if (!client.ConnectAsync("remotehost", remotePort).Wait(1000)){ // connection failure}

代码出处： https://stackoverflow.com/questions/17118632/how-to-set-the-timeout-for-a-tcpclient