unit Main;interfaceuses  SysUtils, Types, Classes, Variants, QGraphics, QControls, QForms, QDialogs,  QStdCtrls, QExtCtrls;type  TFrmMain = class(TForm)    PaintBox: TPaintBox;    BtnDrawShape: TButton;    BtnPoint: TButton;    BtnLine: TButton;    BtnRect: TButton;    procedure BtnDrawShapeClick(Sender: TObject);    procedure BtnPointClick(Sender: TObject);    procedure BtnLineClick(Sender: TObject);  private    { Private declarations }  public    { Public declarations }  end;var  FrmMain: TFrmMain;implementationuses Shapes;{$R *.xfm}procedure TFrmMain.BtnDrawShapeClick(Sender: TObject);var  Shape: TGeoShape;begin  PaintBox.Canvas.Pen.Width := 3;  Shape := TGeoShape.Create();  Shape.Draw( PaintBox.Canvas );  FreeAndNil( Shape );end;procedure TFrmMain.BtnPointClick(Sender: TObject);var  Point: TGeoPoint;begin  PaintBox.Canvas.Pen.Width := 3;  Point := TGeoPoint.Create( 20, 20 );  Point.Draw( PaintBox.Canvas );  FreeAndNil( Point );end;procedure TFrmMain.BtnLineClick(Sender: TObject);var  Line: TGeoLine;begin  PaintBox.Canvas.Pen.Width := 3;  Line := TGeoLine.Create( 10, 50, 300, 50 );  Line.Draw( PaintBox.Canvas );// Draw a point!//  TGeoPoint(Line).Draw( PaintBox.Canvas );  Line.MoveTo( PaintBox.Canvas, 30, 30 );  Line.LineTo( PaintBox.Canvas, 200, 200 );  FreeAndNil( Line );end;end.