环境：net framework 4.5.2

    1. using System;
    2. using System.Collections.Generic;
    3. using System.Drawing;
    4. using System.Drawing.Imaging;
    5. using System.IO;
    6. using System.Linq;
    7. using System.Text;
    8. using System.Threading.Tasks;
    11. public static string Base64ToImg(string base64Code) {
    12.     //先剪切
    13.       string[] Image_Array = base64Code.Split(',');
    14.         byte[] Arr = Convert.FromBase64String(Image_Array[1]);
    15.         try {
    16.         using (MemoryStream stream = new MemoryStream(Arr)) {
    17.             var Source = new Bitmap(stream);
    18.             //转成jpg
    19.             var Eps = new EncoderParameters(1);
    20.             var Ep = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, 85L);
    21.             Eps.Param[0] = Ep;
    23.             ImageCodecInfo jpsEncodeer = null;
    24.             if (Image_Array[0].ToLower() == "data:image/jpeg;base64") {
    25.                 jpsEncodeer = GetEncoder(ImageFormat.Jpeg);
    26.             } else if (Image_Array[0].ToLower() == "data:image/png;base64") {
    27.                 jpsEncodeer = GetEncoder(ImageFormat.Png);
    28.             } else {
    29.                 throw new Exception("");
    30.             }
    31.             //创建路径
    32.             string FilePath = AppDomain.CurrentDomain.BaseDirectory + "/File/Images/";
    33.             if (!System.IO.Directory.Exists(FilePath)) System.IO.Directory.CreateDirectory(FilePath);
    34.             //声明文件类型
    35.             string FileName = string.Format("{0}.jpg", Guid.NewGuid().ToString());
    36.             //保存图片
    37.             Source.Save(string.Format("{0}{1}", FilePath, FileName), jpsEncodeer, Eps);
    38.             //释放资源
    39.             Source.Dispose();
    40.             Ep.Dispose();
    41.             Eps.Dispose();
    42.             return string.Format("/File/Images/{0}", FileName);
    43.         };
    44.     } catch (Exception) {
    45.         return null;
    46.     }
    47. }
    49. /// <summary>
    50. /// 获取文件对象
    51. /// </summary>
    52. /// <param name="format"></param>
    53. /// <returns></returns>
    54. public static ImageCodecInfo GetEncoder(ImageFormat format) {
    55.     ImageCodecInfo[] codecs = ImageCodecInfo.GetImageDecoders();
    56.     foreach (ImageCodecInfo codec in codecs) {
    57.         if (codec.FormatID == format.Guid)
    58.             return codec;
    59.     }
    60.     return null;
    61. }