private void label1_Paint(object sender, PaintEventArgs e)
        {
            Draw(e.ClipRectangle, e.Graphics, 16);
            base.OnPaint(e);
        }
private void Draw(Rectangle rectangle, Graphics g, int _radius)
        {
            Pen shadowPen = new Pen(Color.Blue);
            g.DrawPath(shadowPen, DrawRoundRect(rectangle.X, rectangle.Y, rectangle.Width - 2, rectangle.Height - 1, _radius));
        }
public static GraphicsPath DrawRoundRect(int x, int y, int width, int height, int radius)
        {
            GraphicsPath gp = new GraphicsPath();
            gp.AddArc(x, y, radius, radius, 180, 90);
            gp.AddArc(width - radius, y, radius, radius, 270, 90);
            gp.AddArc(width - radius, height - radius, radius, radius, 0, 90);
            gp.AddArc(x, height - radius, radius, radius, 90, 90);
            gp.CloseAllFigures();
            return gp;
        }