Leave event does not fire on Combo box all the time.
When I move from the combobox on my form I have a leave evernt coded. My problem is that it does not always fire. What is the best event to use so I can test the contents of the combobox once a selection has been made there it be automatcially or by a person clicking the drop down.
SelectedIndexChanged will fire each time a new selection is made by the user or from code.
SelectionChangeCommitted will fire when the user has made a new selection, but not from code.
Both will fire while the focus is still on the control.
If you need to check it once, you may try the Validated event, but if the Leave event is not firing, then the Validated event may not fire either.