Retrieves the image list for the current split button control.
Use this method only with controls whose button style is BS_SPLITBUTTON or BS_DEFSPLITBUTTON.
This method initializes the mask member of a BUTTON_SPLITINFO structure with the BCSIF_IMAGE flag, and then sends that structure in the BCM_GETSPLITINFO message that is described in the Windows SDK. When the message function returns, this method retrieves the image list from the himlGlyph member of the structure.
This method is supported in Windows Vista and later.
Additional requirements for this method are described in Build Requirements for Windows Vista Common Controls.