Отрисовка на Image линии средствами GDI+

class TMyClass
{
    public:
        TMyClass(HDC hdc);
        ~TMyClass();
        void DrawLine1();
        void DrawLine2();
 
    private:
        HDC hdc;
        Gdiplus::Graphics graphics;
        Gdiplus::GdiplusStartupInput gdiplusStartupInput;
        ULONG_PTR gdiplusToken;
};
 
TMyClass::TMyClass(HDC hdc) : graphics(hdc)
{
    Gdiplus::GdiplusStartup(&gdiplusToken, &gdiplusStartupInput, NULL);
    DrawLine1();
}
TMyClass::~TMyClass()
{
    Gdiplus::GdiplusShutdown(gdiplusToken);
}
void TMyClass::DrawLine1()
{
    Gdiplus::Pen pen(Gdiplus::Color(255, 0, 0, 255),1);
    graphics.DrawLine(&pen,0,0,50,50);
}
void TMyClass::DrawLine2()
{
    Gdiplus::Pen pen(Gdiplus::Color(255, 0, 0, 255),1);
    graphics.DrawLine(&pen,50,0,0,50);
}

// файл *.h
class TForm1 : public TForm
{
__published:    // IDE-managed Components
    TImage *Image1;
    TButton *Button1;
    void __fastcall Button1Click(TObject *Sender);
    void __fastcall FormDestroy(TObject *Sender);
private:    // User declarations
    TMyClass *MyClass;
public:     // User declarations
    __fastcall TForm1(TComponent* Owner);
};
 
 
// файл *.cpp
__fastcall TForm1::TForm1(TComponent* Owner)
    : TForm(Owner)
{
    MyClass = new TMyClass(Image1->Canvas->Handle);
    MyClass->DrawLine1();
}
void __fastcall TForm1::Button1Click(TObject *Sender)
{
    MyClass->DrawLine2();
}
void __fastcall TForm1::FormDestroy(TObject *Sender)
{
    delete MyClass;
}