检查文件是否图片格式

  public static bool ValidateImage(string fileName)

        {

            bool isImage = false;

            Image img = Image.FromFile(fileName);

            if (img.RawFormat.Equals(ImageFormat.Jpeg)

                || img.RawFormat.Equals(ImageFormat.Png)

                || img.RawFormat.Equals(ImageFormat.Gif)

                || img.RawFormat.Equals(ImageFormat.Icon))

            {

                isImage = true;

            }

            return isImage;

        }