fuImage 是FileUpload页面控件

ImageHelper.CompressionImage(fuImage.FileBytes, quality);         /// 
        /// Convert Byte[] to Image        /// 
        ///         /// 
            public static Image BytesToImage(byte[] buffer)        {            MemoryStream ms = new MemoryStream(buffer);            Image image = System.Drawing.Image.FromStream(ms);            return image;        }        /// 
        /// Convert Byte[] to a picture and Store it in file        /// 
        ///         ///         /// 
            public static string CreateImageFromBytes(string fileName, byte[] buffer)        {            string file = fileName;            Image image = BytesToImage(buffer);            ImageFormat format = image.RawFormat;            if (format.Equals(ImageFormat.Jpeg))            {                file += ".jpeg";            }            else if (format.Equals(ImageFormat.Png))            {                file += ".png";            }            else if (format.Equals(ImageFormat.Bmp))            {                file += ".bmp";            }            else if (format.Equals(ImageFormat.Gif))            {                file += ".gif";            }            else if (format.Equals(ImageFormat.Icon))            {                file += ".icon";            }            System.IO.FileInfo info = new System.IO.FileInfo(file);            System.IO.Directory.CreateDirectory(info.Directory.FullName);            File.WriteAllBytes(file, buffer);            return file;        }        /// 
        /// 壓縮圖片 /// 
        /// 圖片流        /// 壓縮質量0-100之間 數值越大質量越高        /// 
            private byte[] CompressionImage(Stream fileStream, long quality)        {            using (System.Drawing.Image img = System.Drawing.Image.FromStream(fileStream))            {                using (Bitmap bitmap = new Bitmap(img))                {                    ImageCodecInfo CodecInfo =  GetEncoder(img.RawFormat);                    System.Drawing.Imaging.Encoder myEncoder = System.Drawing.Imaging.Encoder.Quality;                    EncoderParameters myEncoderParameters = new EncoderParameters(1);                    EncoderParameter myEncoderParameter = new EncoderParameter(myEncoder, quality);                    myEncoderParameters.Param[0] = myEncoderParameter;                    using (MemoryStream ms = new MemoryStream())                    {                        bitmap.Save(ms, CodecInfo, myEncoderParameters);                        myEncoderParameters.Dispose();                        myEncoderParameter.Dispose();                        return ms.ToArray();                    }                }            }        }        private static ImageCodecInfo GetEncoder(ImageFormat format)        {            ImageCodecInfo[] codecs = ImageCodecInfo.GetImageDecoders();            foreach (ImageCodecInfo codec in codecs)            {                if (codec.FormatID == format.Guid)                { return codec; }            }            return null;        }