An application sends a CB_SHOWDROPDOWN message to show or hide the list box of a combo box that has the CBS_DROPDOWN or CBS_DROPDOWNLIST style.
CB_SHOWDROPDOWN
wParam = (WPARAM) (BOOL) fShow; // the show/hide flag
lParam = 0; // not used; must be zero
Parameters
fShow
Value of wParam. Specifies whether the drop-down list box is to be shown or hidden. A value of TRUE shows the list box; a value of FALSE hides it.
Return Values
The return value is always TRUE.
Remarks
This message has no effect on a combo box created with the CBS_SIMPLE style.
See Also