c# 应用NPOI 获取Excel中的图片，保存至本地的算法

        private string exclePath = @"C:\users\lenovo\Desktop\testPic.xls";
        private void button2_Click(object sender, EventArgs e)
        {
            List<string> listpath = new List<string>{};
            string savePath = Path.Combine("E:\\","pic"); 
            if(!Directory.Exists(savePath))//判断是否存在保存文件夹，没有则新建
                Directory.CreateDirectory(savePath);

            bool result = ExcelToImage(exclePath, savePath, ref listpath);
            if(result)
               MessageBox.Show("导出成功");
            else
                MessageBox.Show("导出失败");
        }

        /// <summary>
        /// 从excel获取图片
        /// </summary>
        /// <param name="filepath">文件路径</param>
        /// <param name="savepath">图片保存路径</param>
        /// <param name="listPath">返回保存的图表地址list</param>
        /// <returns>保存图片是否成功</returns>
        private bool ExcelToImage(string filepath,string savepath,ref List<string> listPath)
        {
            try
            {
                using (FileStream fsReader = File.OpenRead(filepath))
                {
                    HSSFWorkbook wk = new HSSFWorkbook(fsReader);
                    IList pictures = wk.GetAllPictures();
                    int i = 0;
                    foreach (HSSFPictureData pic in pictures)
                    {
                        //if (pic.Data.Length == 19504) //跳过不需要保存的图片，其中pic.data有图片长度
                        //    continue;
                        string ext = pic.SuggestFileExtension();//获取扩展名
                        string path = string.Empty;
                        if (ext.Equals("jpg"))
                        {
                            Image jpg = Image.FromStream(new MemoryStream(pic.Data));//从pic.Data数据流创建图片
                            path = Path.Combine(savepath, string.Format("pic{0}.jpg", i++));
                            jpg.Save(path);//保存
                        }
                        else if (ext.Equals("png"))
                        {
                            Image png = Image.FromStream(new MemoryStream(pic.Data));
                            path = Path.Combine(savepath, string.Format("pic{0}.png", i++));
                            png.Save(path);
                        }
                        if (!string.IsNullOrEmpty(path))
                            listPath.Add(path);
                    }
                }
            }
            catch (Exception ex)
            {
                return false;
 
            }
                return true;
        }