To retrieve type of a HGDIOBJ object call GetObjectType.
E.g.
GetObjectType( hGdiObj );
Possible return values taken from MSDN…
[sourcecode language=’cpp’]OBJ_BITMAP
OBJ_BRUSH
OBJ_COLORSPACE
OBJ_DC
OBJ_ENHMETADC
OBJ_ENHMETAFILE
OBJ_EXTPEN
OBJ_FONT
OBJ_MEMDC
OBJ_METAFILE
OBJ_METADC
OBJ_PAL
OBJ_PEN
OBJ_REGION[/sourcecode]