DataReceived EventHandler仅工作一次

Question

I am new to stackoverflow. I am having a problem with VC# Serial Communication. I need t receive data conyinuously from serial port but my code works only once. That is if I send "This is a Serial Comm Project". The data is received as expected but if I send the data again it doesn't work. Please provide a solution.

private void button1_Click(object sender, EventArgs e)
{

        mySerialPort.PortName = cbxCOMPort.Text;
        mySerialPort.BaudRate = int.Parse(cbxBaudrate.Text);
        mySerialPort.Parity = Parity.None;
        mySerialPort.StopBits = StopBits.One;
        mySerialPort.DataBits = 8;
        mySerialPort.Handshake = Handshake.RequestToSend;
        mySerialPort.ReadTimeout = int.Parse(cbxTimeout.Text);
        mySerialPort.WriteTimeout = 2000;
        mySerialPort.DtrEnable = true;
        mySerialPort.RtsEnable = true;
        mySerialPort.Encoding = Encoding.ASCII;
        mySerialPort.NewLine = "\r\n";
        mySerialPort.ReadBufferSize = 512;

        mySerialPort.DataReceived += port_DataReceived;

        mySerialPort.Open();

        button1.Enabled = false;
        button2.Enabled = true;
        gbxMsgDel.Enabled = true;

}

private void port_DataReceived(object sender, SerialDataReceivedEventArgs e)
{// Event for receiving data

        // Read the buffer to text box.

        this.Invoke(new EventHandler(DoUpdate));

}

private void DoUpdate(object s, EventArgs e)
{
        receivedMessage += mySerialPort.ReadExisting();

}

receivedMessage is a private string type. It is private to the class.

Answer 1

I had a similar problem before...

From MSDN

"The DataReceived event is not guaranteed to be raised for every byte received"

One option is to use a timer to check available data instead of the event, something like this:

private void checkPortDataTimer_Tick(object sender, EventArgs e)
{
    //You may want to check available bytes instead of this.
    string recievedData = comPort.ReadExisting();
    if (!string.IsNullOrEmpty(recievedData))
        someTextBox.Text += recievedData;
}

Cheers