我正在嘗試使用下面的代碼在Word文檔中添加頁腳。該文件正在生成，但是當我嘗試打開該文件時，它顯示該文檔不可讀的消息。我不知道我在這里做錯了什么。   WordprocessingDocument doc;    Body docBody;    public void Insert()    {        doc = WordprocessingDocument.Create(@"d:\report1.docx", WordprocessingDocumentType.Document);        docBody = new Body();        MainDocumentPart mainPart = doc.AddMainDocumentPart();        mainPart.Document = new Document();        mainPart.Document.Body = docBody;        ApplyFooter();        doc.Save();    }    public void ApplyFooter()    {        // Get the main document part.        MainDocumentPart mainDocPart = doc.MainDocumentPart;        FooterPart footerPart1 = mainDocPart.AddNewPart<FooterPart>("r98");        Footer footer1 = new Footer();        Paragraph paragraph1 = new Paragraph() { };        Run run1 = new Run();        Text text1 = new Text();        text1.Text = "Footer stuff";        run1.Append(text1);        paragraph1.Append(run1);        footer1.Append(paragraph1);        footerPart1.Footer = footer1;        SectionProperties sectionProperties1 = mainDocPart.Document.Body.Descendants<SectionProperties>().FirstOrDefault();        if (sectionProperties1 == null)        {            sectionProperties1 = new SectionProperties() { };            mainDocPart.Document.Body.Append(sectionProperties1);        }        FooterReference footerReference1 = new FooterReference() { Type = DocumentFormat.OpenXml.Wordprocessing.HeaderFooterValues.Default, Id = "r98" };        sectionProperties1.InsertAt(footerReference1, 0);    }