从公制刻度中连续读取值并更新文本框

Question

我需要一些帮助来确定如何使用从公制刻度读取的值更新文本框。 这里的问题是，如何更新它在不同线程中的文本框。 我该如何解决这个问题？

从公制秤返回的值（实时称重示例）

以下是我目前正在使用的代码：

    private void button4_Click(object sender, EventArgs e)
    {
        DoSomething();
    } 

    void DoSomething()
    {
        if (InvokeRequired)
        {
            Invoke(new MethodInvoker(updateGUI));
        }
        else
        {
            // Do Something
            updateGUI();
        }
    }

    void updateGUI()
    {
        // update gui here
        Connect();

        //------------------------------------------------
        //Only updates once after clicking the button
        textBox1.Text = this._LastReadValue;
        //------------------------------------------------
    }

    public void Connect()
    {

        try
        {
            // Close the socket if it is still open
            if (m_sock != null && m_sock.Connected)
            {
                m_sock.Shutdown(SocketShutdown.Both);
                System.Threading.Thread.Sleep(10);
                m_sock.Close();
            }

            // Create the socket object
            m_sock = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);

            // Define the Server address and port
            IPEndPoint epServer = new IPEndPoint(IPAddress.Parse(textBox2.Text), 4001);

            // Connect to the server blocking method and setup callback for recieved data
            // m_sock.Connect( epServer );
            // SetupRecieveCallback( m_sock );

            // Connect to server non-Blocking method
            m_sock.Blocking = false;
            AsyncCallback onconnect = new AsyncCallback(OnConnect);

            m_sock.BeginConnect(epServer, onconnect, m_sock);
        }
        catch (Exception ex)
        {
            throw new Exception(ex.Message);
        }
    }

    private void OnConnect(IAsyncResult ar)
    {
        // O socket foi passado no objecto
        Socket sock = (Socket)ar.AsyncState;

        // Verificar se conexao foi efectuada com sucesso
        try
        {
            // sock.EndConnect( ar );
            if (sock.Connected)
            {
                //m_lbRecievedData.Items.Add("Connected");
                SetupRecieveCallback(sock);
            }
            else
            {
                // reset ao socket
                m_sock = null;

                // reiniciar socket
                Connect();
                //throw new Exception("Incapaz de conectar à máquina remota. Conexao falhou!");
            }
        }
        catch (Exception ex)
        {
            throw new Exception("Error in Proxy.NetComm.OnConnect(): " + ex.Message);

        }
    }

    /// <summary>
    /// Setup o callback para receber dados ou perda de ligacao
    /// </summary>
    private void SetupRecieveCallback(Socket sock)
    {
        try
        {
            AsyncCallback recieveData = new AsyncCallback(OnRecievedData);
            //sock.BeginReceive( m_byBuff, 0, m_byBuff.Length, SocketFlags.None, recieveData, sock );
            sock.BeginReceive(m_byBuff, 0, m_byBuff.Length, SocketFlags.None, recieveData, sock);
        }
        catch (Exception ex)
        {
            throw new Exception(ex.Message);
        }
    }

    private void OnRecievedData(IAsyncResult ar)
    {
        // O Socket foi passado no objecto
        Socket sock = (Socket)ar.AsyncState;

        if (m_sock.Connected == false)
            return;

        // verificar se há dados
        try
        {
            int nBytesRec = sock.EndReceive(ar);

            if (nBytesRec > 0)
            {
                // converter em string
                string sRecieved = Encoding.ASCII.GetString(m_byBuff, 0, nBytesRec);

                //this._Mensagem = this._Mensagem + sRecieved;
                this._Mensagem = sRecieved;

                // verificar se fim dos dados recebidos (carriage return)
                if (sRecieved.IndexOf("\n") != -1)
                {
                    // despoletar evento
                    if (ReceivedData != null)
                        ReceivedData(this._Mensagem);

                    this._LastReadValue = this._Mensagem;

                    //------------------------------------------------
                    //Error here
                    textBox1.Text = this._LastReadValue;
                    //------------------------------------------------

                    this._Mensagem = "";
                }

                // WARNING : The following line is NOT thread safe. Invoke is
                // m_lbRecievedData.Items.Add( sRecieved );
                //Invoke( m_AddMessage, new string [] { sRecieved } );

                // If the connection is still usable restablish the callback
                SetupRecieveCallback(sock);
            }
            else
            {
                // If no data was recieved then the connection is probably dead
                sock.Shutdown(SocketShutdown.Both);
                sock.Close();

                throw new Exception("Client {0}, disconnected" + sock.RemoteEndPoint);

            }
        }
        catch (Exception ex)
        {
            sock.Close();
            //throw new Exception(ex.Message);
        }
    }

谢谢

Answer 1

你真的很可能想要这样的东西，并避免所有这些跳来跳去。

private async void button4_Click(object sender, EventArgs e)
{
    using (var m_sock = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp))
    {
        IPEndPoint epServer = new IPEndPoint(IPAddress.Parse(textBox2.Text), 4001);
        await m_sock.ConnectAsync(epServer);
        if (m_sock.Connected)
        {
            int nBytesRec = await m_sock.ReceiveAsync(new ArraySegment<byte>(m_byBuff, 0, m_byBuff.Length), SocketFlags.None);
            if (nBytesRec > 0)
            {
                string sRecieved = Encoding.ASCII.GetString(m_byBuff, 0, nBytesRec);
                string mensagem = sRecieved;
                if (sRecieved.IndexOf("\n") != -1)
                {
                    ReceivedData?.Invoke(mensagem);
                    this._LastReadValue = mensagem;
                    textBox1.Text = mensagem;
                }
            }
            else
            {
                m_sock.Shutdown(SocketShutdown.Both);
                m_sock.Close();
            }
        }
    }
}

async / await是你的朋友。