//是这样的吗
procedure TForm1.Button1Click(Sender: TObject);
begin
Image1.Canvas.MoveTo(1, 1);
Image1.Canvas.LineTo(100, 100);
end;
procedure TForm1.Button1Click(Sender: TObject);
begin
Image1.Canvas.MoveTo(1, 1);
Image1.Canvas.LineTo(100, 100);
end;
!!!!!!that is a esay way for you : use ABC components TABCLine (download from www.obsof.com)