Question

I’m working in a thread to check the GPRS connection in CompactFramework.

The idea of the thread is simple: If the program isn’t connected then I run the code to connect (this code is giving me errors), but if the connection is OK then I recheck again in 60 seconds and so on.

Now, focusing in connection code. The following code check if it’s connected or not, if it isn’t then I subscribe to DataReceive event.

void initFormText()
{
    if (isThereConnect()) //true if it is connected
    {
       //enable timer to recheck if it's connected
    }
    else //it isn't connected
    {  

        serialPort1.DataReceived += new System.IO.Ports.SerialDataReceivedEventHandler(serialPort1_DataReceived);
        if (serialPort1.IsOpen)
        {
            serialPort1.Close();
        }
        serialPort1.Open();   

        timerStep.Enabled = true;
    }    
}  

Now comes the issue, in the serialPort1_DataReceived I check the data and set a variable which is tested by the timerStep and it make some steps.

The problem occurs in the DataReceived event, the thing is that when I run the following code outside of a thread it works fine, it does all the job and make the connection, but in the thread it doesn’t work. I test this adding some MessageBoxand I realize that the ones inside the DataReceive never appear.

void serialPort1_DataReceived(object sender, System.IO.Ports.SerialDataReceivedEventArgs e)
{
    byte[] data = new byte[1024];
    int n = serialPort1.Read(data, 0, data.Length);
    string rec = Encoding.GetEncoding("windows-1252").GetString(data, 0, n);

    if (string.IsNullOrEmpty(rec))
    {
        return;
    }

    if (rec.Contains("AT+CIMI") && rec.Contains("OK"))
    {
        MessageBox.Show("serialPort 1");
        currState = 1;
    }
    else if (rec.Contains("READY"))
    {
        MessageBox.Show("serialPort 11");
        currState = 1;
    }
    else if (rec.Contains("0,1") || rec.Contains("0,5"))
    {
        MessageBox.Show("serialPort 2");
        currState = 2;
    }
}

So by some reason the serialPort isn’t receiving anything and I can’t figure it out why. The fact that it works outside the thread but not in the thread is frustrating me.

I appreciate any help. Thanks in advanced!

Answer 1

Yes, but I think that your thread finishes before event is fired. You should create your Form in a following manner, please note that this is code for desktop but simulates what is available in CompactFramework since I don’t have it installed here. First Form1 is main form and it starts thread in which is the Form2. The Form2 has a button and Click EventHandler that is working, but you need to show your Form2 with Application.Run(). Here is the sample code:

 public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
    }

    private void button1_Click(object sender, EventArgs e)
    {
        Thread thread = new Thread(new ThreadStart(ThreadMethod));
        thread.SetApartmentState(ApartmentState.STA);
        thread.Start();
    }
    void ThreadMethod()
    {
            Form2 f = new Form2();
            Application.Run(f);
    }
}  

public partial class Form2 : Form
{
    public Form2()
    {
        InitializeComponent();
    }

    private void button1_Click(object sender, EventArgs e)
    {
        MessageBox.Show("Something");
    }
}

Hope it will work this way.