C# .net core 图片缩放压缩

       public static string Save(this IFormFile file)
        {

            var NewFileName = $"{Guid.NewGuid()}{Path.GetExtension(file.FileName)}";

            var path = Path.Combine($"{Directory.GetCurrentDirectory()}\\wwwroot", "upload");

            if (!Directory.Exists(path))
                Directory.CreateDirectory(path);

            //Resiser 调用缩放
            //Save 压缩保存
            Image.FromStream(file.OpenReadStream()).Resizer(1080).Save($"{path}\\{NewFileName}", 80);

            return  $"upload/{npath}/{NewFileName}";

        }


        /// <summary>
        /// 按宽度缩放
        /// </summary>
        /// <param name="bmp"></param>
        /// <param name="width"></param>
        /// <returns></returns>
        private static Image Resizer(this Image bmp, int width)
        {
            if (bmp.Width < width || width == 0) return bmp;

            Bitmap ob = new Bitmap(width, bmp.Height * width / bmp.Width);

            using (var g = Graphics.FromImage(ob))
            {
                g.Clear(Color.WhiteSmoke);
                g.DrawImage(bmp, new Rectangle(0, 0, ob.Width, ob.Height), 0, 0, bmp.Width, bmp.Height, GraphicsUnit.Pixel);
            }
            return ob;
        }
        /// <summary>
        /// path:路径；quality：质量；
        /// </summary>
        /// <param name="bmp"></param>
        /// <param name="path">路径</param>
        /// <param name="quality">质量</param>
        public static void Save(this Image bmp,string path,int quality) {

            EncoderParameters eps = new EncoderParameters();

            eps.Param[0] = new EncoderParameter(Encoder.Quality, quality);

            bmp.Save(path, ImageCodecInfo.GetImageEncoders().FirstOrDefault(x => x.FormatID == ImageFormat.Jpeg.Guid), eps);

        }