Problem beom Bewegen der Image. man sieht Streifen

[Blup]

Repaint scheint zu funktionieren, zusätzlich muss danach noch ValidateRect aufgerufen werden, damit der störende Effekt verschwindet.

Delphi-Quellcode:

procedure TFTest.ImageMouseMove(Sender: TObject; Shift: TShiftState; X,
  Y: Integer);
var
  Diff: Integer;
  ControlPos: TPoint;
  ControlRect: TRect;
begin
  if (ssLeft in Shift) and (Sender = Selected.Control) then
  begin
    ControlPos.X := Selected.Control.Left + X - Selected.Pos.X;
    ControlPos.Y := Selected.Control.Top  + Y - Selected.Pos.Y;
    {Element im Clientbereich einsperren}
    with Selected.Control.Parent.ClientRect do
    begin
      Diff := Right - (ControlPos.X + Selected.Control.Width);
      if Diff < 0 then
        ControlPos.X := ControlPos.X + Diff;

      Diff := Left - ControlPos.X;
      if Diff > 0 then
        ControlPos.X := ControlPos.X + Diff;

      Diff := Bottom - (ControlPos.Y + Selected.Control.Height);
      if Diff < 0 then
        ControlPos.Y := ControlPos.Y + Diff;

      Diff := Top - ControlPos.Y;
      if Diff > 0 then
        ControlPos.Y := ControlPos.Y + Diff;
    end;

    with Selected.Control do
    begin
      if (Left <> ControlPos.X) or (Top <> ControlPos.Y) then
      begin
        SetBounds(ControlPos.X, ControlPos.Y, Width, Height);
        Repaint;
        ControlRect := BoundsRect;
        ValidateRect(Parent.Handle, @ControlRect);
      end;
    end;
  end;
end;