Fillrect hat falschen Hintergrund

[Der schöne Günther]

Delphi-Quellcode:

uses System.UITypes;

{$R *.dfm}

type
   TCanvasHelper = class helper for Vcl.Graphics.TCanvas
      procedure setBrushBackgroundColor(const color: TColor);
   end;

procedure TForm2.PaintBoxPaint(Sender: TObject);
var
   c: TCanvas;
begin
   c := (Sender as TPaintBox).Canvas;

   c.Brush.Style := TBrushStyle.bsDiagCross;
   c.Brush.Color := TColors.Aqua;
   c.setBrushBackgroundColor(TColors.Red);

   c.FillRect( TRect.Create(10, 10, 100, 100) );
end;

procedure TCanvasHelper.setBrushBackgroundColor(const color: TColor);
begin
   Win32Check( SetBkColor(Handle, color) <> 0 );
end;