Question about wrapper PagedGeometry

hi,i am a newer with paged geometry. i wrapped pagedgeometry1.1.1 with c++/cli. But with the compiled dll i can not see the trees which loaded. So ,i think i was wrong somewhere in wrapping. The "PagedGeometry::addDetail<>" function troubled me most. Here is my way to create it:
public ref class PagedGeometry: System::IDisposable
{
protected:
Forests::PagedGeometry *pagedGeometry;
public:
void addDetailLevelBatchPage(float maxRange, float transitionLength)
{
pagedGeometry->addDetailLevel<Forests::BatchPage>((Ogre::Real)maxRange,(Ogre::Real)transitionLength);
};

void addDetailLevelImpostorPage(float maxRange, float transitionLength)
{
pagedGeometry->addDetailLevel<Forests::ImpostorPage>((Ogre::Real)maxRange,(Ogre::Real)transitionLength);
};
}
Would you tell me if this is true or not? If not true,please tell me the right way. Thanks ..