程序代码：

    private: System::Void button1_Click(System::Object^  sender, System::EventArgs^  e) 
             {
                 int _x = int::Parse(textBox1->Text);
                 int _y = int::Parse(textBox2->Text);
                 int _r = int::Parse(textBox3->Text);
                 
                 Image^ MyImage = gcnew Bitmap(pictureBox1->Width, pictureBox1->Height);
                 Graphics^ g = Graphics::FromImage(MyImage);
                 Pen^ mypen = gcnew Pen(Color::Black, 1);
                 Rectangle rect = Rectangle(_x-_r, _y-_r, 2*_r, 2*_r);
                 
                 g->DrawEllipse( mypen, rect );
                 g->DrawRectangle(mypen,rect);

                 rect = Rectangle(_x-_r*1.414, _y-_r*1.414, 2*(_r*1.414), 2*(_r*1.414));
                 g->DrawEllipse( mypen, rect );

                 this->pictureBox1->Image = nullptr;
                 this->pictureBox1->Image =  (Image^)MyImage->Clone();

                 delete g;
                 delete MyImage;
                 delete mypen;
             }