Create Rectangle to WebBroser C#

Problem for paint a graphic to WebBrowseron C# I create a custom WebBrowser and i want to create a rectangle on Custom WebBrowser but this never happend. i need help please

public class PenWebview : WebBrowser { protected override void WndProc(ref Message m) { //base.WndProc(ref m);

        switch (m.Msg)
        {
            case WmPaint:
                using (var graphics = Graphics.FromHwnd(Handle))
                {
                    // Create pen.
                    Pen blackPen = new Pen(Color.Black, 3);

                    // Create rectangle.
                    Rectangle rect = new Rectangle(0, 0, 200, 200);

                    // Draw rectangle to screen.
                    graphics.DrawRectangle(blackPen, rect);


                    SolidBrush blueBrush = new SolidBrush(Color.Blue);

                    // Create rectangle.
                    Rectangle rect2 = new Rectangle(Width / 2, Height / 2, 400, 400);

                    // Fill rectangle to screen.
                    graphics.FillRectangle(blueBrush, rect2);

                    //appActive = (((int)m.WParam != 0));





                }
                return;
            default:
                base.WndProc(ref m);
                break;
                // case WM_ACTIVATEAPP:

                //    // The WParam value identifies what is occurring.
                //    appActive = (((int)m.WParam != 0));

                //    // Invalidate to get new text painted.
                //    this.Invalidate();

                //    break;
        }

    }

}