清除画布上的图画???

Question

if  Button= mbLeft then
begin
ha:=GetDeskTopWindow();
a:=GetWindowDC(ha);
canv := TCanvas.Create;
canv.Handle:=a;
canv.Draw(1,1,DBpicture.Picture.Graphic);
end;
if  Button= mbRight then  //按右键想清除canv上的图像
begin
;  //??怎么写
end;

Answer 1

cav.Brush.Color:=clblack;//或需要的颜色
  cav.FillRect(rect(0,0,100,100));

Answer 2

Image1.Canvas.FillRect(Image1.Canvas.ClipRect);

Answer 3

Image1.Canvas.FillRect(Image1.Canvas.ClipRect);

Answer 4

Image1.width:=0;
Image1.hight:=0;