public static byte[] BitmapTObyte(Bitmap 图)
       {
           MemoryStream ms = new MemoryStream();
           图.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
           byte[] bt = ms.GetBuffer();
           ms.Close();
           return bt;
       }
       public static Bitmap BitmapTObyte(byte[] content)
       {
           MemoryStream ms = new MemoryStream();
           ms.Write(content, 0, content.Length);
           Bitmap myBitmap = new Bitmap(ms);
           ms.Close();
           return myBitmap;
       }