我通过使用Socket.ConnectAsync方法而不是Socket.Connect方法解决了该问题。调用Socket.ConnectAsync（SocketAsyncEventArgs）后，启动计时器（timer_connection），如果时间到了，请检查套接字连接是否已连接（if（m_clientSocket.Connected）），如果没有，则弹出超时错误。

private void connect(string ipAdd,string port)
    {
        try
        {
            SocketAsyncEventArgs e=new SocketAsyncEventArgs();


            m_clientSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);

            IPAddress ip = IPAddress.Parse(serverIp);
            int iPortNo = System.Convert.ToInt16(serverPort);
            IPEndPoint ipEnd = new IPEndPoint(ip, iPortNo);

            //m_clientSocket.
            e.RemoteEndPoint = ipEnd;
            e.UserToken = m_clientSocket;
            e.Completed+=new EventHandler<SocketAsyncEventArgs>(e_Completed);                
            m_clientSocket.ConnectAsync(e);

            if (timer_connection != null)
            {
                timer_connection.Dispose();
            }
            else
            {
                timer_connection = new Timer();
            }
            timer_connection.Interval = 2000;
            timer_connection.Tick+=new EventHandler(timer_connection_Tick);
            timer_connection.Start();
        }
        catch (SocketException se)
        {
            lb_connectStatus.Text = "Connection Failed";
            MessageBox.Show(se.Message);
        }
    }
private void e_Completed(object sender,SocketAsyncEventArgs e)
    {
        lb_connectStatus.Text = "Connection Established";
        WaitForServerData();
    }
    private void timer_connection_Tick(object sender, EventArgs e)
    {
        if (!m_clientSocket.Connected)
        {
            MessageBox.Show("Connection Timeout");
            //m_clientSocket = null;

            timer_connection.Stop();
        }
    }