Question

I have a TreeView populated with TreeNodes having icons and checkboxes.

I’ve been tryig to disable the checkig/unchecking ability of some of them discarding the event in the BerforeCheck method. This works fine, until I double click on the checkbox: the image of the checkbox is the opposite of its real state (it shows a check mark if the status is Checked=false). I’ve tried to fix that changing the StateImageIndex manually in the NodeDoubleClick and BeforeClick method with no success.

Even worse: I added a third image in the StateImageList (yes I want the checkboxes to be tri-state too) but I’m not using it yet (it’s never set in my code), and the third image is set as the current state of the box after some double-click (at this point I can’t determine a clear behavior).

How can I do to at best make it work as exepected, at worst disable the double-click on the checkbox?
Thanks.

PS: The question has already been asked, but had no answer…

Answer 1

Try this.. 🙂 worked for me

public class NewTreeView : TreeView
    {
        protected override void WndProc(ref Message m)
        {
            if (m.Msg == 0x203)
                m.Result = IntPtr.Zero;
            else
                base.WndProc(ref m);
        }
    }