//这是我看到的一个程序
procedure TForm1.Button1Click(Sender: TObject);
begin
with Form1.Canvas do
begin
Pen.Width:=2;//坐标轴粗一些
Pen.Color:=clblue;
Pen.Style:=psSolid;
MoveTo(40,20); //原点(40,270)
LineTo(40,270); //纵轴
LineTo(280,270);//横轴
{以下代码画箭头}
MoveTo(35,25);
LineTo(40,20);
LineTo(45,25);
MoveTo(275,265);
LineTo(280,270);
LineTo(275,275);
end;
end;