MouseClick event of RadDropDownList.Popup is fired when you click the popup opened through the arrow button. If you have AutoComplete DropDownList popup it is necessary to subscribe additionally to its MouseClick event in order to catch it:
If your case is different, a sample project will be greatly appreciated.
I hope this information helps. Should you have further questions, I would be glad to help.
Regards,
Desislava
Telerik
TRY TELERIK'S NEWEST PRODUCT - EQATEC APPLICATION ANALYTICS for WINFORMS.
Learn what features your users use (or don't use) in your application. Know your audience. Target it better. Develop wisely. Sign up for Free application insights >>