演示 Rect、Bounds 生成 TRect 的区别

本例效果图:

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    Button1: TButton;
    RadioGroup1: TRadioGroup;
    procedure RadioGroup1Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

var
  R: TRect;

procedure TForm1.FormCreate(Sender: TObject);
begin
  RadioGroup1.Items.CommaText := 'Undo,Rect,Bounds';
  R := Button1.BoundsRect;
end;

procedure TForm1.RadioGroup1Click(Sender: TObject);
begin
  case RadioGroup1.ItemIndex of
    0: Button1.BoundsRect := R;
    1: Button1.BoundsRect := Rect(50,50,100,80);  {参数3、4 是一个点}
    2: Button1.BoundsRect := Bounds(50,50,100,80);{参数3、4 分别是宽度与高度}
  end;
end;

end.