The framework calls this member function for the owner of an owner-draw button control, combo-box control, list-box control, or menu when a visual aspect of the control or menu has changed.
The itemAction member of the DRAWITEMSTRUCT structure defines the drawing operation that is to be performed. The data in this member allows the owner of the control to determine what drawing action is required.
Before returning from processing this message, an application should ensure that the device context identified by the hDC member of the DRAWITEMSTRUCT structure is restored to the default state.
If the hwndItem member belongs to a CButton, CMenu, CListBox, or CComboBox object, then the DrawItem virtual function of the appropriate class is called. Override the DrawItem member function of the appropriate control's class to draw the item.
This member function is called by the framework to allow your application to handle a Windows message. The parameters passed to your function reflect the parameters received by the framework when the message was received. If you call the base-class implementation of this function, that implementation will use the parameters originally passed with the message and not the parameters you supply to the function.