An application sends an STM_GETIMAGE message to retrieve the handle of the image associated with a static control.
STM_GETIMAGE wParam = (WPARAM) fImageType; // image-type flag lParam = 0; // not used; must be zero
IMAGE_BITMAP
IMAGE_CURSOR
IMAGE_ENHMETAFILE
IMAGE_ICON
The return value is the handle of the image, if any; otherwise, it is NULL.