The HDF_VG_GETNEXT function returns the reference number of the next object inside a VGroup in a Hierarchical Data Format file. If Id is -1, the first item in the VGroup is returned, otherwise Id should be set to a reference number previously returned by HDF_VG_GETNEXT. HDF_VG_GETNEXT returns -1 if there was an error or there are no more objects after the one specified by Id .

Calling Sequence

Result = HDF_VG_GETNEXT( VGroup, Id )



The VGroup handle returned by a previous call to HDF_VG_ATTACH.


A VGroup or VData reference number obtained by a previous call to HDF_VG_GETNEXT. Alternatively, this value can be set to -1 to return the first item in the VGroup.