#region 根据richtextbox创建GDI+

         private void DrawGDI(RichTextBox rich,Panel panl,PictureBox p2)

         {

             rich.Update();

             Bitmap bmp = new Bitmap(rich.Width, rich.Height);

             using (Graphics gr = Graphics.FromImage(bmp))

             {

                 gr.CopyFromScreen(rich.PointToScreen(Point.Empty), Point.Empty, rich.Size);

             }

             p2.Image = bmp;

             panl.Controls.Remove(rich);

             panl.Controls.Add(p2);

             panl.Update();

         }

         #endregion