Yes, of course, but I need to draw something like a mini screenshot which is different nearly every time it is drawn and depends on the position of
every window.

So how can you redraw the paintbox complete in OnPaint?

Benito

Benito van der Zander wrote

So how can you redraw the paintbox complete in OnPaint?

This is a hack, so I hope another may show you how to do it properly.

Add a boolean flag to your form class thus:

type
  TForm1 = class( TForm )
    ...
    private
    FOnPaintCalled: boolean;
    ...
end;

and a Formcreate event handler to initialise FOnPaintCalled:

PROCEDURE Tform1 .Formcreate ( Sender : Tobject ) ;
BEGIN
  inherited;
  FOnPaintCalled := false;
End;

and write the OnPaint handler as follows:

PROCEDURE Tform1 .Paintbox1paint ( Sender : Tobject ) ;
BEGIN
  PaintBox1.Canvas.brush.Color:=rgb( random(255), random(255), random(255) );
  PaintBox1.Canvas.Rectangle(0, 0, 100, 100);
  if not FOnPaintCalled then Paintbox1.Invalidate;
  FOnPaintCalled := not FOnPaintCalled;
End;

Regards

Howard