.net图片压缩

1.png很难进行压缩，一般压缩时间较长。

2.jpg图片压缩方法：

 #region  图片压缩【之压缩jpg】
        public static void JpgImgZip(Image img,string filePath)
        {
             //以下代码为保存图片时，设置压缩质量
            EncoderParameters ep = new EncoderParameters();
            long[] qy = new long[1];
            qy[0] =60;//设置压缩的比例1-100
            EncoderParameter eParam = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, qy);
            ep.Param[0] = eParam;
            try
            {
                ImageCodecInfo jpegICIinfo = GetEncoderInfo("JPG");
                if (jpegICIinfo != null)
                {
                    img.Save(filePath, jpegICIinfo, ep);//dFile是压缩后的新路径
                }
                else
                {
                    img.Save(filePath, System.Drawing.Imaging.ImageFormat.Jpeg);
                }
            }
            catch(Exception)
            {
                img.Save(filePath, System.Drawing.Imaging.ImageFormat.Jpeg);
            }
        }
        public static ImageCodecInfo GetEncoderInfo(String fileExtenUper)
        {
            int j;
            ImageCodecInfo[] encoders;
            encoders = ImageCodecInfo.GetImageEncoders();
            for (j = 0; j < encoders.Length; ++j)
            {
                if (encoders[j].FilenameExtension.Contains(fileExtenUper))
                {
                    return encoders[j];
                }
            }
            return null;
        }
        #endregion