WinAPI: OffsetRect - 移动矩形

本例效果图:

---

unit Unit1;



interface



uses

  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.