Tif文件转换成GIF列表

 /// <summary>
        /// 将TIF文件转换为GIF文件列表
        /// </summary>
        /// <param name="fileName">要转换的TIF文件</param>        
        /// <returns>转换后生成的GIF文件路径</returns>
        public static IList<string> ConvertTifToGif(string fileName)
        {
            IList<string> list = new List<string>();

            string dic = AppDomain.CurrentDomain.BaseDirectory + "\\tempgif\\";

            if (!Directory.Exists(dic))
            {
                Directory.CreateDirectory(dic);
            }

            if (string.IsNullOrEmpty(fileName))
            {
                throw new ArgumentException("转换的TIF文件路径不能为空");
            }

            FileInfo file = new FileInfo(fileName);

            if (!file.Exists)
            {
                throw new FileNotFoundException("待转换的TIF文件不存在");
            }

            Image imgObj = Image.FromFile(file.FullName);


            //Image imgObj = imgObj2.GetThumbnailImage(imgObj2.Width / 3 * 2, imgObj2.Height / 3 * 2, null, IntPtr.Zero); //Image.FromFile(file.FullName);

            Guid objGuid = (Guid)imgObj.FrameDimensionsList.GetValue(0);

            FrameDimension objDimension = new FrameDimension(objGuid);
            

            int totalImage = imgObj.GetFrameCount(objDimension);

            for (int index = 0; index < totalImage; index++)
            {
                string gifPath = dic + file.Name.Substring(0, file.Name.LastIndexOf('.')) + "_" + index + ".gif";

                if (File.Exists(gifPath))
                {
                    File.Delete(gifPath);
                }

               //EncoderParameter en = new EncoderParameter();

                imgObj.SelectActiveFrame(objDimension, index);
                imgObj.Save(gifPath, ImageFormat.Gif);
                FileInfo item = new FileInfo(gifPath);
                list.Add("tempgif\\" + item.Name);
            }

            return list;
        }