读取嵌入到word的Excel对象

Word.Document doc = this._wordApplication.Documents.Add(@"C:\Users\linmeicheng\Desktop\新建文件夹 (3)\Doc1.docx");
                        foreach (Word.ContentControl item in doc.ContentControls)
                        {
                            string title = item.Title;
                           // item.Appearance = WdContentControlAppearance.wdContentControlHidden;

                            System.Diagnostics.Debug.WriteLine("标题："+ title);
                            System.Xml.XmlDocument xmldoc = new System.Xml.XmlDocument();
                            xmldoc.LoadXml(item.Range.WordOpenXML);

                            System.Xml.XmlNamespaceManager manager = new System.Xml.XmlNamespaceManager(xmldoc.NameTable);
                            manager.AddNamespace("pkg", "http://schemas.microsoft.com/office/2006/xmlPackage");

                           var aa=  xmldoc.SelectSingleNode("//pkg:package/pkg:part[@pkg:contentType='application/vnd.openxmlformats-officedocument.spreadsheetml.sheet']/pkg:binaryData", manager);
                            if (aa == null)
                                continue;

                            //NetOffice.ExcelApi.Application excel = new NetOffice.ExcelApi.Application();

                            Stream stream = new MemoryStream(Convert.FromBase64String(aa.InnerText));

                            ExcelUntity excel = new ExcelUntity();
                            SpreadsheetDocument spreadsheetDocument = excel.Open(stream, false);

                            SheetData sheetData = spreadsheetDocument.GetFirstSheetData();
                            SharedStringTablePart sharedStringTablePart = spreadsheetDocument.GetSharedStringTable().FirstOrDefault();

                            foreach(Row row in sheetData)
                            {
                                if (row.RowIndex == )
                                    continue;

                                string bb = row.GetCellValue("B"+row.RowIndex.ToString(), sharedStringTablePart);
                                string cc = row.GetCellValue("C" + row.RowIndex.ToString(), sharedStringTablePart);

                                System.Diagnostics.Debug.WriteLine("第" + row.RowIndex.ToString()+"行,B列："+bb+" C列:"+cc);
                            }
                            spreadsheetDocument.Close();
                        }