_stateWindowLevel = true;
wxVTKRenderWindowInteractor *wxVTKiren;
wxVTKiren = _vtkInteractorStyleBaseView->GetWxVtk2DBaseView()->GetWxVTKRenderWindowInteractor();
wxVTKiren->GetEventPosition( _backPx , _backPy );
_stateWindowLevel = true;
wxVTKRenderWindowInteractor *wxVTKiren;
wxVTKiren = _vtkInteractorStyleBaseView->GetWxVtk2DBaseView()->GetWxVTKRenderWindowInteractor();
wxVTKiren->GetEventPosition( _backPx , _backPy );