deilphi中用什么控件画弧？该怎么处理

unit Unit1;

interface

uses
 Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, ExtCtrls;



type
  TForm1 = class(TForm)
    Button1: TButton;
    Button2: TButton;
    Button3: TButton;
    Button4: TButton;
    Button5: TButton;
    Button6: TButton;
    Button7: TButton;
    Image1: TImage;
    procedure FormCreate(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
    procedure Button4Click(Sender: TObject);
    procedure Button5Click(Sender: TObject);
    procedure Button1Click(Sender: TObject);
    procedure Button6Click(Sender: TObject);
    procedure Button7Click(Sender: TObject);
    procedure Image1MouseDown(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

var
  btn: TButton;
const
  y1 = 10;
  y2 = 80;


{先设置画笔画刷}
procedure TForm1.FormCreate(Sender: TObject);
begin
  Canvas.Pen.Width := 2;
  Canvas.Pen.Color := clRed;
  Canvas.Brush.Color := clWhite;
end;




procedure TForm1.Image1MouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin

end;

{绘制椭圆; 椭圆的参数和矩形是一样的}
procedure TForm1.Button1Click(Sender: TObject);
begin
  btn := TButton(Sender);
  Canvas.Ellipse(btn.Left, y1, btn.Left+btn.Width, y2);
end;


{根据矩形结构绘制椭圆}
procedure TForm1.Button2Click(Sender: TObject);

var
  R: TRect; {定义一个矩形结构}
begin
  btn := TButton(Sender);
  R := Rect(btn.Left, y1, btn.Left+btn.Width, y2);
  Canvas.Ellipse(R);
end;


{绘制扇形}

procedure TForm1.Button3Click(Sender: TObject);
begin
  btn := TButton(Sender);
  Canvas.Pie(
    btn.Left, y1,                             {矩形区域左上角}
    btn.Left + btn.Width, y2,                 {矩形区域右下角}
    btn.Left + btn.Width, y1 + (y2-y1) div 2, {扇形起点}
    btn.Left + btn.Width div 2, y1);            {扇形终点}
end;


{绘制弦, 参数同上}
procedure TForm1.Button4Click(Sender: TObject);
begin
    btn := TButton(Sender);
  Canvas.Chord(
    btn.Left, y1,
    btn.Left + btn.Width, y2,
    btn.Left + btn.Width, y1 + (y2-y1) div 2,
    btn.Left + btn.Width div 2, y1 );
end;





{绘制弧线, 参数同上}
procedure TForm1.Button5Click(Sender: TObject);
begin
  btn := TButton(Sender);
  Canvas.Arc(
    btn.Left, y1,
    btn.Left + btn.Width, y2,
    btn.Left + btn.Width, y1 + (y2-y1) div 2,
    btn.Left + btn.Width div 2, y1
  );
end;
procedure TForm1.Button6Click(Sender: TObject);
begin
 canvas.MoveTo(100,100); //将画笔移动到(100，100)处
 canvas.LineTo(200,200); //从(100，100)画一条直线到(200，200)
end;

procedure draw_cen(cen_point,Length:integer);//绘制中心线
begin

end;

procedure TForm1.Button7Click(Sender: TObject);
var
 w_cen,h_cen:Integer;

begin
 with Image1 do
 begin
  Canvas.Pen.Color   :=   clRed; //设置颜色
  w_cen:=Image1.Width div 2;    //x中心点
  h_cen:=Image1.Height div 2;   //y中心点


  Canvas.Rectangle(w_cen-10,h_cen-10,w_cen+10,h_cen+10); //绘制矩形


  canvas.MoveTo(w_cen,h_cen); //将画笔移动到中心处
  canvas.LineTo(w_cen,h_cen+50); //向上绘制50

  canvas.MoveTo(w_cen,h_cen); //将画笔移动到中心处
  canvas.LineTo(w_cen,h_cen-50); //向上绘制50

  canvas.MoveTo(w_cen,h_cen); //将画笔移动到中心处
  canvas.LineTo(w_cen+50,h_cen); //向上绘制50

  canvas.MoveTo(w_cen,h_cen); //将画笔移动到中心处
  canvas.LineTo(w_cen-50,h_cen); //向上绘制50
  Update;
 end;

end;

end.

------解决方案--------------------
 窗体上放 button1~button7 7个按钮可以测试 ,我以前写的片段，图上不来

------解决方案--------------------
http://topic.csdn.net/t/20021027/17/1129260.html
这是Delphi的例子，建议遇到不懂的，自己先 google下。