Question

I have a modal dialog with a cancel button only which pops up when the user clicks on a button. Aftre the modal dialog pops up, I would like to start a long process which monitors external event. If the event happens, then the dialog will be closed automatically. The user can cancel the monitoring process by clicking the cancel button.

I assigned the process start to the Shown event

private void ProceedForm_Shown(object sender, System.EventArgs e)
{
    controller.StartSwiping();
}

The process itself is a loop

public void StartSwiping()
{           
    Status status;
    do
    {
        status = CallForFeedback();
    } while (status == Status.Pending);           

    form.DialogResult = DialogResult.OK;
    form.Close();
}

The process starts fine, but the dialog does not pop up, so the user can non cancel the process. I also tried to assign the start to the Load event, but nothing changed.
Is there any way to Show the dialog and after that start the process?

Thanks

Answer 1

Your problem is that you are doing everything in the UI thread. You need to put you status monitoring loop in a separate thread so that the UI thread can remain responsive.

There are several ways you can do this, but one easy place to start is with the BackgroundWorker class