WM_DRAWITEM
lpdis = (LPDRAWITEMSTRUCT) lParam; /* item-drawing information */
The WM_DRAWITEM message is sent to the owner window of an owner-draw button, combo-box, list-box, or menu when a visual aspect of the button, combo box, list box, or menu has changed.
lpdis
Value of lParam. Points to a DRAWITEMSTRUCT structure that contains information about the item to be drawn and the type of drawing required.
The DRAWITEMSTRUCT structure has the following form:
typedef struct tagDRAWITEMSTRUCT { /* dis */
UINT CtlType;
UINT CtlID;
UINT itemID;
UINT itemAction;
UINT itemState;
HWND hwndItem;
HDC hDC;
RECT rcItem;
DWORD itemData;
} DRAWITEMSTRUCT;
An application should return TRUE if it processes this message.
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.
DRAWITEMSTRUCT