An application sends the CB_GETDROPPEDWIDTH message to retrieve the minimum allowable width, in pixels, of the list box of a combo box with the CBS_DROPDOWN or CBS_DROPDOWNLIST style.
CB_GETDROPPEDWIDTH
wParam = 0; // not used, must be zero
lParam = 0; // not used, must be zero
This message has no parameters.
If the message succeeds, the return value is the width, in pixels.
If the message fails, the return value is CB_ERR.
By default, the minimum allowable width of the drop-down list box is 0. The width of the list box is either the minimum allowable width or the combo box width, whichever is larger.
Windows NT: Requires version 4.0 or later.
Windows: Requires Windows 95 or later.
Windows CE: Requires version 1.0 or later.
Header: Declared in winuser.h.
Combo Boxes Overview, Combo Box Messages, CB_SETDROPPEDWIDTH