图片压缩

        /// <summary>
        /// 将图片按百分比压缩
        /// </summary>
        public static bool ImageCompress(Image source, string savePath, byte percent)
        {
            var parameters = new EncoderParameters();
            parameters.Param[0] = new EncoderParameter(Encoder.Quality, new long[] { percent });
            try
            {
                ImageCodecInfo[] arrayICI = ImageCodecInfo.GetImageDecoders();
                ImageCodecInfo jpegICIinfo = arrayICI.SingleOrDefault(a => a.FormatDescription.Equals("JPEG", StringComparison.OrdinalIgnoreCase));
                if (jpegICIinfo != null)
                    source.Save(savePath, jpegICIinfo, parameters);
                else
                    source.Save(savePath, source.RawFormat);
                return true;
            }
            catch (Exception ex)
            {
                return false;
            }
            finally
            {
                source.Dispose();
            }
        }
        public static Bitmap PercentImage(Image srcImage)
        {
            int newW = srcImage.Width < 1130 ? srcImage.Width : 1130;
            int newH = int.Parse(Math.Round(srcImage.Height * (double)newW / srcImage.Width).ToString());
            try
            {
                Bitmap b = new Bitmap(newW, newH);
                Graphics g = Graphics.FromImage(b);
                g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.Default;
                g.DrawImage(srcImage, new Rectangle(0, 0, newW, newH), new Rectangle(0, 0, srcImage.Width, srcImage.Height), GraphicsUnit.Pixel);
                g.Dispose();
                return b;
            }
            catch (Exception)
            {
                return null;
            }
        }