[quote user="Frode Tørresdal"]I write DgnRasterCollection:: the GetRasters Method is not shown[/quote]
Do you mean that Viz Studio IntelliSense doesn't show the methods of that class?
Presumably you've #included <RasterCollection.h> or<RasterCoreAPI.h> (which #includes <RasterCollection.h>)? GetRasters() is a static public method of DgnRasterCollection.