unit Unit1;interfaceuses  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,  Dialogs, StdCtrls;type  TForm1 = class(TForm)    Button1: TButton;    Button2: TButton;    Button3: TButton;    Button4: TButton;    Button5: TButton;    procedure Draw;    procedure FormCreate(Sender: TObject);    procedure Button1Click(Sender: TObject);    procedure Button2Click(Sender: TObject);    procedure Button3Click(Sender: TObject);    procedure Button4Click(Sender: TObject);    procedure Button5Click(Sender: TObject);  end;var  Form1: TForm1;implementation{$R *.dfm}var  R: TRect;procedure TForm1.Draw;begin  Refresh;  Canvas.FillRect(R);end;procedure TForm1.FormCreate(Sender: TObject);begin  Button1.Caption := '绘制矩形';  Button2.Caption := '上移';  Button3.Caption := '下移';  Button4.Caption := '左移';  Button5.Caption := '右移';end;procedure TForm1.Button1Click(Sender: TObject);begin  R := Bounds(80, 60, 60, 60);  Randomize;  Canvas.Brush.Color := Random($FFFFFF);  Draw;end;procedure TForm1.Button2Click(Sender: TObject);begin  OffsetRect(R, 0, -10);  Draw;end;procedure TForm1.Button3Click(Sender: TObject);begin  OffsetRect(R, 0, 10);  Draw;end;procedure TForm1.Button4Click(Sender: TObject);begin  OffsetRect(R, -10, 0);  Draw;end;procedure TForm1.Button5Click(Sender: TObject);begin  OffsetRect(R, 10, 0);  Draw;end;end.