The WM_DRAWITEM message is sent to the owner window of an owner-drawn button, combo box, list box, or menu when a visual aspect of the button, combo box, list box, or menu has changed.
WM_DRAWITEM
idCtl = (UINT) wParam; // control identifier
lpdis = (LPDRAWITEMSTRUCT) lParam; // item-drawing information
Parameters
idCtl
Value of wParam. Specifies the identifier of the control that sent the WM_DRAWITEM message. If the message was sent by a menu, this parameter is zero.
lpdis
Value of lParam. Points to a DRAWITEMSTRUCT structure containing information about the item to be drawn and the type of drawing required.
Return Values
If an application processes this message, it should return TRUE.
Default Action
The DefWindowProc function draws the focus rectangle for an owner-drawn list box item.
Remarks
The itemAction member of the DRAWITEMSTRUCT structure specifies the drawing operation that an application should perform.
Before returning from processing this message, an application should ensure that the device context identified by the hDC member of the DRAWITEMSTRUCT structure is in the default state.
See Also