Q: How to owner draw CComboBox's drop button? How can I do owner draw CComboBox's drop button? 
Thanks.

A: You can right click on the Combo Box and check its properties, you will notice there will be a  Owner Draw button. Double click on it to make it visible so that it becomes user-defined and can be changed according to your input.
If you are using strings, you can enable the 'Has Strings' part from the properties menu. Along with that if you need to add user-defined string data to your combo box, you can use 'Insertstring' or 'AddString' string commands to get your combo box working your way.
Hope this helps.
