ComboBox DropDown

[Shaun Becker]

I need to create a combo box control with a custom drop down. Now, before I try to create this from scratch, is there a way to disable the drop down? Thanks for your help

[Not Active]

Disable the dropdown? You mean like a listbox?

[Shaun Becker]

No, I need to disable the drop down box for the combobox control. I need to do this so that I can have a custom drop down appear.

[Heath Stewart]

You could try extending ComboBox, then override WndProc. For the CBN_DROPDOWN notification message (msg id 7), return instead of calling the base.WndProc:

protected override void WndProc(ref Message m)
{
if (m.Msg == 7) return;
base.WndProc(ref m);
}

That may stop it, but the documentation for that notification message doesn't mention how to stop it. By not passing the notification message to the ComboBox, though, it shouldn't display the popup window that represents the drop-down. It's worth a shot. Also, you should consider making your own from scratch. If the above doesn't work, it's often easier making your own controls that trying to change existing ones. Remember that almost every control in System.Windows.Forms is just a wrapper class for their Windows Common Controls equivalent, so the true behavior of the control itself is defined by native code. If you must make your own, I suggest you download something like .NET Reflector[^] to peer inside how the System.Windows.Forms.ComboBox works for things that aren't apparent in the documentation.

-----BEGIN GEEK CODE BLOCK----- Version: 3.21 GCS/G/MU d- s: a- C++++ UL@ P++(+++) L+(--) E--- W+++ N++ o+ K? w++++ O- M(+) V? PS-- PE Y++ PGP++ t++@ 5 X+++ R+@ tv+ b(-)>b++ DI++++ D+ G e++>+++ h---* r+++ y+++ -----END GEEK CODE BLOCK-----