C#缩略图生成并返回byte[]

/// <summary>
        /// 生成缩略图返回byte[]
        /// </summary>
        /// <param name="fileName"></param>
        /// <returns></returns>
        private byte[] GetByteByPic(string fileName) 
        {
            MemoryStream ms = new MemoryStream();

            Bitmap bitmap = new Bitmap(fileName);
           
            //获取原图片的宽和高
            int width = bitmap.Width;   
            int height = bitmap.Height;
            Rectangle newPic = new Rectangle(0, 0, width, height);
            
             //创建原图片的副本
            System.Drawing.Image newImg = bitmap.Clone(newPic, 
System.Drawing.Imaging.PixelFormat.DontCare);     
            System.Drawing.Image.GetThumbnailImageAbort myCallback = new Image.GetThumbnailImageAbort(CallBack);

              //设置生成后的缩略图,其中200,200表示你需要得到的宽和高 
            System.Drawing.Image myThumbnail = bitmap.GetThumbnailImage(200, 200, CallBack, IntPtr.Zero);   
            
            //保存到内存里
            myThumbnail.Save(ms, System.Drawing.Imaging.ImageFormat.Bmp);
            
            myThumbnail.Dispose();  //释放图片资源
            newImg.Dispose();
            bitmap.Dispose();

            return ms.ToArray(); //内在里解出来返回byte[]
        }

        private static bool CallBack()  //这个委托方法需要是static的
        {
            return false;
        }