[vtkusers] Manually creat a polydata set with cells??

[qin zeng]

Hi, all,
 I am new user of VTK.

I just wonder how to create a polydata set with cells
I used to use vtkdelaunay2d, but the result is that no cell.

Why?
I ask the question is because only polydata with cell can use vtkCountourFilter. Is that right?

Thanks

qin