Aborting a Thread.

[Ronni Marker]

Hi I have the following code that is updating an dropdown box with information Active Directory information - this below will show Domain Controllers btw. But I am trying unsuccessfully to cancel an existing running thread if one exist already. this is mainly because sometimes a thread can be running indefinitely and need to abort that, or if another thread is called that need to update the same dropdownbox. Anyway are there any out here who could explain how I could abort an running thread?

    private void ThreadDC()
    {

        Thread TRDomainC = new Thread(ThreadingDC);
        if (TRDomainC.IsAlive)
        {
            TRDomainC.Abort();
        }
        TRDomainC.SetApartmentState(ApartmentState.STA);
        TRDomainC.Start();
    }

    private void ThreadingDC()
    {
        comboBox1.Items.Clear();
        try
        {
            if (comboBoxDomains.SelectedIndex >= 0 && comboBoxDomains.SelectedIndex != -1)
            {
                foreach (string dc in domainInfoComponent\[comboBoxDomains.SelectedItem.ToString()\])
                {
                    comboBox1.Items.Add(dc);
                }
                lastIndex = comboBoxDomains.SelectedIndex;
                comboBox1.SelectedIndex = 0;
            }
        }
        catch
        {
            lastIndex = 0;
            comboBox1.SelectedIndex = -1;
        }
    }

[Nicholas Butler]

Don't use Thread.Abort - it's evil! If you want to end a thread, do it cooperatively - make the thread return from it's main method and it will be cleared up properly. Also, you cannot touch UI controls from any thread other than your main UI thread. Control.Invoke is helpful here. Here is a good introduction to threading: http://www.albahari.com/threading/[^] Nick

---------------------------------- Be excellent to each other :)

[Luc Pattyn]

As Nick said; this[^] may help also. :)

Luc Pattyn [Forum Guidelines] [Why QA sucks] [My Articles]

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Merry Christmas and a Happy New Year to all.

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[Ronni Marker]

Not really an option waiting. So need to kill the thread one way or another. I know about Control.Invoke, but well, dosn't really help me on ending the thread before it is completed. Ronni

[Ronni Marker]

Nope, not really. Well I could move to backgroundworker... But there should(right?) be a way to abort the thread without getting into the deep end.

[Luc Pattyn]

As Nick and Albahari say, you should not even want to abort a thread, aborting it will leave a lot of objects in an unknown state, putting the app at the risk of a deadlock; how about things that may be locked and never will be unlocked again? You really need the cooperative approach for thread control. And a healthy way to access GUI Controls, hence the reference to my article. :)

Luc Pattyn [Forum Guidelines] [Why QA sucks] [My Articles]

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Merry Christmas and a Happy New Year to all.

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