Outlook VSTO(C#)中mailItem.GetInspector.WordEditor返回错误邮件正文问题

我正在编写Outlook VSTO(C#)脚本，用于导出邮件附件及将邮件导出为PDF，要求PDF包含发件人、收件人、主题、附件等信息，与直接打印PDF内容一致。

由于Outlook VSTO无直接导出PDF的方法，因此采用先将邮件保存为Word文档再自行补充信息的方案。代码逻辑为遍历选中的每个MailItem，传入CustomMailItem类处理导出。初期运行正常，但在处理某些加载耗时较长的邮件时，inspector.WordEditor返回的始终是选中的第一封邮件的正文，而CustomMailItem中的mailItem对象是正确的（邮件头及.msg导出正常）。尝试使用Thread.Sleep、inspector.Display()及Activate()均无法解决加载问题。

核心代码 #

主函数代码（已移除无关部分） #

private void exportAllSelected_Click(object sender, EventArgs e)
{
CustomMailItem thisCustomMailItem = null;
Word.Application wordApp = null;
int maxItems = 0;
int currentIndex = 0;
try
{
#region Initialise
GetExportOptions();

        if (exportOptions.word || exportOptions.pdf)
        {
            wordApp = new Word.Application();
            wordApp.Visible = true; //Debug only
        }
    
        #endregion
    
        // Run with background worker and progress bar
        ProgressHelper.RunWithProgress((worker, progressTracker) =>
        {
            #region Explorer
            progressTracker.UpdateStatus($"Getting mail items");
            Application outlookApp = Globals.ThisAddIn.Application;
            Explorer explorer = outlookApp.ActiveExplorer();
            maxItems = explorer.Selection.Count;
            #endregion
    
            foreach (object item in explorer.Selection)
            {
                MailItem mailItem = null;
                try
                {
                    //Checks to skip non MailItems
    
                    #region Export
                    thisCustomMailItem = new CustomMailItem(mailItem, exportOptions, wordApp);
                    thisCustomMailItem.ExportAll();
                    #endregion
    
                }
                catch (Exception ex)
                {
                    // Log Error if required
                }
                finally
                {
                    if (mailItem != null) { Marshal.ReleaseComObject(mailItem); }
                    if (thisCustomMailItem != null) { thisCustomMailItem.ReleaseItems(); }
                }
            }
        });
    
    }
    catch (Exception ex)
    {
        // Log Error if required
    }
    finally
    {
        if (thisCustomMailItem != null) { thisCustomMailItem.ReleaseItems(); }
        if (wordApp != null)
        {
            wordApp.Quit();
            Marshal.FinalReleaseComObject(wordApp);
            wordApp = null;
        }
    }

}

CustomMailItem类相关代码 #

Word.Document tempDoc;
Inspector inspector;
private void GetWordDoc()
{
#region Save word document from mailItem
inspector = mailItem.GetInspector;
System.Threading.Thread.Sleep(100);

    if (!(inspector.IsWordMail() && inspector.EditorType == OlEditorType.olEditorWord))
    {
        throw new Exception("Selected item is not word mail");
    }
    
    Word.Document oDoc = inspector.WordEditor;
    bool isODocNull = oDoc == null;
    oDoc.SaveAs2(paths.word);
    System.Threading.Thread.Sleep(100);
    
    #region Discard
    Marshal.FinalReleaseComObject(oDoc);
    oDoc = null;
    inspector.Close(OlInspectorClose.olDiscard);
    Marshal.FinalReleaseComObject(inspector);
    inspector = null;
    #endregion
    
    #endregion
    
    #region Format Word Doc
    RetryForBusy(() => { tempDoc = wordApp.Documents.Open(paths.word); }); // Manual inspection shows the contents of this document defaults to the first email in selection at some point.
    
    // Do other operations with Word Doc Here (e.g. add sender, subject, export as PDF)
    #endregion

}

内容的提问来源于stack exchange，提问作者ZQ G