How to detect if items are added to a ListBox (or CheckedListBox) control

Question

This seems like a fundamentally simple question. I have a WinForms dialog box with a listbox. This control is not populated via data-binding but is filled with call

Answer 1

Unfortunately, there's no easy way to do this using inheritance or events. You should be able to override the Add method of the Items class, but you can't get to it! You may be able to intercept the message loop to figure out when this is happening, but that's beyond my experience.

One thing I noticed from your question is that you mention items are being added asynchronously. Don't do that. Your problem may be solved if you synchronize on the form's thread (if your problem is that the control isn't updating).