Usage of OnDrawLinkPoint

VCL TMS Diagram Studio
1

I'm trying to draw my own linkpoints by using OnDrawLinkPoint, but it seems that the TCanvas parameter doesn't draw anything. An example of code:


void __fastcall TMainForm::DiagramDrawLinkPoint(TObject *Sender, TCanvas *ACanvas, TLinkPoint *ALinkPoint, TPoint &APoint, bool &DrawingDone)
{
DrawingDone = true;

ACanvas->Brush->Color = clBlack;
ACanvas->Pen->Color = clBlack;

ACanvas->Rectangle(APoint.X - 2, APoint.Y - 2, APoint.X + 2, APoint.Y + 2);
}

I noticed that every drawing method uses DgrDrawer.Canvas (the graphic lib is Direct2D), and this event uses Drawer.Canvas. Isn't this related?
2

OnDrawLinkPoint event was created when Diagram Studio only had GDI drawing option. So that's why it only works in that mode, unfortunately. For GDI+ or Direct2D, you have to use one of the predefined link points.