if (pictureBox1.Image != null)
            {
                System.Drawing.Bitmap map = new Bitmap(pictureBox1.Image);
                Graphics g = Graphics.FromImage(map);
                Pen pen = new Pen(Color.Red, 10);
                int width = pictureBox1.Width;
                int height = pictureBox1.Height;
                Rectangle WeiXingRe = new Rectangle((int)(width * 0.28), (int)(height * 0.27), (int)(width * 0.35), (int)(height * 0.05));
                g.DrawRectangle(pen, WeiXingRe);
            }
            else
            {
                MessageBox.Show("请选择图片");
            }