Question

I have a serial port class, and I would like to control send/receive via my GUI, and have the GUI update based on receipt of data from the serial port (or other events). So the two relevant classes are the serial class and the main window class.

I have the code below which compiles, but I get an exception when I try to run.

public class MySerThread
{
    public SerialPort serport;
    public event SerialDataReceivedEventHandler newSerData;

    public MySerThread()
    {
        serport = new SerialPort("COM1", 115200);
        serport.Open();
        serport.DataReceived += DataReceivedHandler;
    }

    public void DataReceivedHandler(object s, SerialDataReceivedEventArgs e)
    {
        byte[] data = new byte[serport.BytesToRead];
        serport.Read(data, 0, data.Length);

        // here's where I think I'm going wrong?
        if(newSerData != null)
            newSerData(s,e);
    }
}

And then in my GUI class…

public partial class MainWindow : Window
{
    MySerThread myPort;

    public MainWindow()
    {
        // Exception triggers here
        myPort.newSerData += DisplaySerDataHandler;
    }

    private void DisplaySerDataHandler(object sender, SerialDataReceivedEventArgs e)
    {
        this.ReceivedCallback(e);
    }

    private void ReceivedCallback(SerialDataReceivedEventArgs e)
    {
        if(this.someTextBlock.Dispatcher.CheckAccess())
        {
            this.UpdateTextBlock(e);
        }
        else
        {
            this.someTextBlock.Dispatcher.BeginInvoke(new Action<SerialDataReceivedEventArgs>(this.UpdateTextBlock), e);
        }
    }

    private void UpdateTextBlock(SerialDataReceivedEventArgs e)
    {
        someTextBlock.Text = "got new data";
    }
}

So, what am I doing wrong here? What is the best way to do this?

Answer 1

You can’t access myPort without creating an instance.

MySerThread myPort = new MySerThread();