求助C#调用OneNote

调用Orc_Img方法时，这段代码运行会报异常，求大神帮忙解决

[C#] 纯文本查看 复制代码

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml.Linq;
using System.Xml;
using System.IO;
using System.Configuration;
using System.Drawing;
using System.Drawing.Imaging;
using System.Runtime.InteropServices;
using Microsoft.Office.Core;
using Microsoft.Office.Interop.Graph;
using Microsoft.Office.Interop.OneNote;
using System.Diagnostics;
using System.Windows.Forms;

namespace LH_design_of_graduation
{
    public class OrcImage
    {
        int waitTime = 100;
        string tmpPath = AppDomain.CurrentDomain.BaseDirectory + @"newfile";

        private Tuple<string, int, int> GetBase64(string strImgPath)
        {
            return GetBase64(new FileInfo(strImgPath));
        }

        /// <summary>
        /// 获取图片的Base64编码
        /// </summary>
        /// <param name="file"></param>
        /// <returns></returns>
        /// 图片资源应该转换成为 Base64 码
        private Tuple<string, int, int> GetBase64(FileInfo file)
        {
            using (MemoryStream ms = new MemoryStream())
            {
                Bitmap bp = new Bitmap(file.FullName);
                switch (file.Extension.ToLower())
                {
                    case ".jpg":
                        bp.Save(ms, ImageFormat.Jpeg);
                        break;

                    case ".jpeg":
                        bp.Save(ms, ImageFormat.Jpeg);
                        break;

                    case ".gif":
                        bp.Save(ms, ImageFormat.Gif);
                        break;

                    case ".bmp":
                        bp.Save(ms, ImageFormat.Bmp);
                        break;

                    case ".tiff":
                        bp.Save(ms, ImageFormat.Tiff);
                        break;

                    case ".png":
                        bp.Save(ms, ImageFormat.Png);
                        break;

                    case ".emf":
                        bp.Save(ms, ImageFormat.Emf);
                        break;

                    default:
                        return new Tuple<string, int, int>("不支持的图片格式。", 0, 0);
                }
                byte[] buffer = ms.GetBuffer();
                return new Tuple<string, int, int>(Convert.ToBase64String(buffer), bp.Width, bp.Height);
            }
        }

        public string Orc_Img(FileInfo fi)
        {
            // 向Onenote2013中插入图片  新建一个 OneNote 对象
            var onenoteApp = new Microsoft.Office.Interop.OneNote.Application();  //onenote提供的API
                                                                                  ///***************************************************************************************/
                                                                                  ///建立一个 One 文件
            string sectionID;
            
            string tmpPath = AppDomain.CurrentDomain.BaseDirectory + "tmpPath/";
            onenoteApp.OpenHierarchy(tmpPath + "newfile.one", null, out sectionID, CreateFileType.cftSection);
            //创建一个新的页面，所以我们要使用到 CreateNewPage 函数，它的 out 参数则存储了 pageID
            string pageID = "{A975EE72-19C3-4C80-9C0E-EDA576DAB5C6}{1}{B0}";  // 格式 {guid}{tab}{??}
            onenoteApp.CreateNewPage(sectionID, out pageID, NewPageStyle.npsBlankPageNoTitle);
            /********************************************************************************/
            string notebookXml;
            onenoteApp.GetHierarchy(null, HierarchyScope.hsPages, out notebookXml);
            var doc = XDocument.Parse(notebookXml);
            var ns = doc.Root.Name.Namespace;
            var pageNode = doc.Descendants(ns + "Page").FirstOrDefault();
            var existingPageId = pageNode.Attribute("ID").Value = pageID;

            //按照 onenote 的标准利用 XmlDocument 对象将资源进行包装
            if (pageNode != null)
            {
                Tuple<string, int, int> imgInfo = this.GetBase64(fi);
                var page = new XDocument(
                                new XElement(
                                    ns + "Page",
                                    new XElement(
                                       ns + "Outline",
                                       new XElement(
                                           ns + "OEChildren",
                                           new XElement(
                                               ns + "OE",
                                               new XElement(
                                                   ns + "Image",
                                                   new XAttribute("format", fi.Extension.Remove(0, 1)),
                                                   new XAttribute("originalPageNumber", "0"),
                                                   new XElement(
                                                       ns + "Position",
                                                       new XAttribute("x", "0"),
                                                       new XAttribute("y", "0"),
                                                       new XAttribute("z", "0")),
                                                       new XElement(
                                                           ns + "Size",
                                                           new XAttribute("width", imgInfo.Item2),
                                                           new XAttribute("height", imgInfo.Item3)),
                                                           new XElement(ns + "Data", imgInfo.Item1)
                                                            )
                                                         )
                                                      )
                                                   )
                                                )
                                             );

                page.Root.SetAttributeValue("ID", existingPageId);
                //将数据插入到 page 中
                onenoteApp.UpdatePageContent(page.ToString(), DateTime.MinValue);
            //延时0.1秒
            flag1:
                Stopwatch sw = new Stopwatch();// 开始计时
                sw.Start();
               
                int fileSize = Convert.ToInt32(fi.Length / 1024 / 1024); // 文件大小 单位M
                System.Threading.Thread.Sleep(waitTime * (fileSize > 1 ? fileSize : 1));
                
                string pageXml;
                onenoteApp.GetPageContent(existingPageId, out pageXml, PageInfo.piBinaryData);
                /*********************************************************************************/
                //通过 XmlDocument 对象，获取到识别结果
                XmlDocument xmlDoc = new XmlDocument();
                xmlDoc.LoadXml(pageXml);
                XmlNamespaceManager nsmgr = new XmlNamespaceManager(xmlDoc.NameTable);
                nsmgr.AddNamespace("one", ns.ToString());

                XmlNode xmlNode = xmlDoc.SelectSingleNode("//one:Image//one:OCRText", nsmgr);
                if (xmlNode == null)
                {
                    goto flag1;
                }
                string strRet = xmlNode.InnerText;

                sw.Stop();//结束计时
                long times = sw.ElapsedMilliseconds;
                Console.WriteLine("执行查询总共使用了" + times + "毫秒");//显示时间
                                                              ///**********************************************************************/
                onenoteApp.DeleteHierarchy(existingPageId, DateTime.MinValue);  // 摧毁原始页面
                //////////////////////////////////////////////////////////////////////////////
                

                System.Threading.Thread.Sleep(100);
                return strRet;
            }

            return "没有识别";
        }

    }
}

怎么报错

错误原因截图