Compute method

Hello, i have a problem with the compute method. It is dealing with WireFrame display. I made a simple object CBloc3D which has to change wire color here is my code:

I create a wireaspect with my constructor with

CBloc3D::CBloc3D() :Cobjet3D() { ... myDrawer->SetWireAspect(new Prs3d_LineAspect(Quantity_NOC_BLACK,Aspect_TOL_SOLID,4)); ... }

And when i display it i use

void CBloc3D::Compute(const Handle(PrsMgr_PresentationManager3d)& aPresentationManager,const Handle(Prs3d_Presentation)& aPresentation, const Standard_Integer aMode ) { switch (aMode) {

case 0: myDrawer->WireAspect()->SetColor (Quantity_NOC_BLACK); myDrawer->WireAspect()->SetWidth(4); StdPrs_WFShape::Add(aPresentation,m_tpdsShape, myDrawer );

break;

} }

MY GREAT PROBLEM IS THAT MY OBJECT IS ALWAYS STILL DISPLAYED IN YELLOW WITH A WIDTH OF 1 :) in the wire mode although i insist on creating the same aspect and computing the same aspect as the creation. I know that i have to load the line presentation before displaying the first time. But why in shading aspect is it working well and not as well in wire aspect? It would be a great help if someone could explain how it is really working in wire mode. Thx anyway.