procedure TForm1.FormCreate(Sender: TObject);
begin
  Rectangle1.Width := 100;
  Rectangle1.Height := 100;
  Rectangle1.Fill.Color := claYellow;
  Rectangle1.Stroke.Color := claRed;
  {居中; 喜欢这种带枚举名的赋值方式}
  Rectangle1.Align := TAlignLayout.alCenter;
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  {旋转中心点: [0.5,0.5] 是默认值, 表示控件的中心点; [0,0] 和 [1,1] 分别表示控件的左上角和右下角}
  Rectangle1.RotationCenter.X := 0.5;
  Rectangle1.RotationCenter.Y := 0.5; //
  {旋转角度}
  Rectangle1.RotationAngle := 45;
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
  {透明度: 0.0 - 1.0}
  Rectangle1.Opacity := 0.5;
end;