修改 VSTO Outlook 加载项的 MailItem.Body

我们一直试图编辑电子邮件的 html 正文以进行回复和转发。我们有一个自定义表单，我们希望将标题附加到 html 电子邮件正文，具体取决于它是新的电子邮件回复还是转发。您如何让新正文覆盖回复和转发的电子邮件正文。主题工作得很好。

namespace OutlookAddIn
{
    public partial class ThisAddIn
    {
        private Outlook.Inspectors inspectors;
        private void ThisAddIn_Startup(object sender, System.EventArgs e)
        {
            inspectors = this.Application.Inspectors;
            inspectors.NewInspector += new Microsoft.Office.Interop.Outlook.InspectorsEvents_NewInspectorEventHandler(Inspectors_NewInspector);
        }
        private void ThisAddIn_Shutdown(object sender, System.EventArgs e)
        {
            // Note: Outlook no longer raises this event. If you have code that 
            //    must run when Outlook shuts down, see http://go.microsoft.com/fwlink/?LinkId=506785
        }
        void Inspectors_NewInspector(Microsoft.Office.Interop.Outlook.Inspector Inspector)
        {
            Outlook.MailItem mailItem = Inspector.CurrentItem as Outlook.MailItem;
            if (mailItem != null)
            {
                if (mailItem.EntryID == null)
                {
                    ClassificationForm formMain = new ClassificationForm();
                    formMain.ShowDialog();
                    mailItem.HTMLBody = formMain.GetHTMLBody();
                    mailItem.Subject = formMain.GetSubject();
                }
            }
        }
        #region VSTO generated code
        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InternalStartup()
        {
            this.Startup += new System.EventHandler(ThisAddIn_Startup);
            this.Shutdown += new System.EventHandler(ThisAddIn_Shutdown);
        }
        #endregion
    }
}

也尝试了这个，它确实替换了正文的html电子邮件，但它确实打开了两个版本的电子邮件，并且ForwardingMessage.Display（true）不能完全显示电子邮件的编辑版本。

Outlook.MailItem ForwardingMessage = (Outlook.MailItem)this.Application.CreateItem(Outlook.OlItemType.olMailItem);
Outlook.MailItem SelectedMessage = (Outlook.MailItem)this.Application.ActiveExplorer().Selection[1];
if (SelectedMessage != null)
{
    if (ForwardingMessage != null)
    {
        ClassificationForm formMain = new ClassificationForm();
        formMain.ShowDialog();
        SelectedMessage.HTMLBody = formMain.GetHTMLBody();
        SelectedMessage.Subject = formMain.GetSubject();
     }
}