[vtkusers] subclassing vtkInteractorStyle

[Konrad Sickel]

Hello,

i try to write my own interactor. Therefore i want to subclass the 
vtkInteractorStyleTrackballCamera style. I looked in the code of the 
other styles and tryed:

class VTK_RENDERING_EXPORT vtkMyInteractorStyleUser : public 
vtkInteractorStyleTrackballCamera{
public:
    static vtkMyInteractorStyleUser *New();
 
};

When i include this class no error happens, but if i want use it:

vtkMyInteractorStyleUser *style = vtkMyInteractorStyleUser::New();
 iren->SetInteractorStyle( style );

i geht an linking error with not resolved symbols:

Cone error LNK2019: Nicht aufgelöstes externes Symbol '"public: static 
class vtkMyInteractorStyleUser * __cdecl 
vtkMyInteractorStyleUser::New(void)" 
(?New at vtkMyInteractorStyleUser@@SAPAV1 at XZ)', verwiesen in Funktion '_main'

The programm works without problems if a vtk style is used.
vtk 5.0, win xp, visual studio 2003 (7), projekt constructed with cmake 2.2

Thanks for any help and ideas!
Konrad