vtkTextWidget

Hi masters,
I want to realize these effects below:
1. set border line color and style for vtkTextWidget;
2. set background color for vtkTextWidget;
for No.2 item,i’ve tried calling vtkActorText*->GetTextProperty()->SetBackgroundColor(xx,xx,xx),but it
doesn’t take effect. Since i’m new for vtk, could you teach me with patience. Much thanks~