[Qt-interest] undefined reference to QVTKWidget::QVTKWidget

[Yifei Li]

Hi all,
I'm trying to compile an example of Qt4 and VTK integration - 
SimpleView.  Although I included all the libraries (I use qmake):
LIBS += -L/usr/lib \
          -lQVTK \
       -lvtkHybrid \
       -lvtkVolumeRendering \
       -lvtkIO \
       -lvtkRendering \
       -lvtkGenericFiltering \
       -lvtkGraphics \
       -lvtkImaging \
       -lvtkFiltering \
       -lvtkCommon \
       -lvtkftgl \
       -lvtkDICOMParser \
       -lvtksys

compilation still failed with the error message:
In function `Ui_MainWindow::setupUi(QMainWindow*)': undefined reference 
to `QVTKWidget::QVTKWidget(QWidget*, QFlags<Qt::WindowType>)'

The undefined reference error occurred in ui_uiSimpleView4.h (qvtkwidget 
= new QVTKWidget(someParentWidget)), which is automatically generated by 
qt/eclipse integration.
The other function call qvtkwidget->GetRenderWindow() does not cause any 
linking error.

If I remove -lQVTK from 'LIBS', I'll get another linking error:
undefined reference to 'QVTKWidget::GetRenderWindow()'

So I think the dynamic library libQVTK.so must have been linked, at 
least partially.

HOWEVER, using cmake DOES NOT cause any linking errors.

Could anyone tell me where I am wrong?  Thank you very much

Yifei