“Error Creating Window Handle”

Question

We\'re working on a very large .NET WinForms composite application - not CAB, but a similar home grown framework. We\'re running in a Citrix and RDP environment running on

Answer 1

I ran into the same .Net runtime error but my solution was different.

My Scenario: From a popup Dialog that returned a DialogResult, the user would click a button to send an email message. I added a thread so the UI didn't lock up while generating the report in the background. This scenario ended up getting that unusual error message.

The code that resulted in problem: The problem with this code is that the thread immediately starts and returns which results in the DialogResult being returned which disposes the dialog before the thread can properly grab the values from the fields.

private void Dialog_SendEmailSummary_Button_Click(object sender, EventArgs e)
{
    SendSummaryEmail();
    DialogResult = DialogResult.OK;
}

private void SendSummaryEmail()
{
    var t = new Thread(() => SendSummaryThread(Textbox_Subject.Text, Textbox_Body.Text, Checkbox_IncludeDetails.Checked));
    t.Start();
}

private void SendSummaryThread(string subject, string comment, bool includeTestNames)
{
    // ... Create and send the email.
}

The fix for this scenario: The fix is to grab and store the values before passing them into the method which creates the thread.

private void Dialog_SendEmailSummary_Button_Click(object sender, EventArgs e)
{
    SendSummaryEmail(Textbox_Subject.Text, Textbox_Body.Text, Checkbox_IncludeDetails.Checked);
    DialogResult = DialogResult.OK;
}

private void SendSummaryEmail(string subject, string comment, bool includeTestNames)
{
    var t = new Thread(() => SendSummaryThread(subject, comment, includeTestNames));
    t.Start();
}

private void SendSummaryThread(string subject, string comment, bool includeTestNames)
{
    // ... Create and send the email.
}