VSTO Outlook 加载项 - 发送项目的处理程序并不总是有效

Question

我有一个 Outlook 插件，可以处理某种类型的已发送电子邮件。对于某些类型的电子邮件，用户必须填写一些信息的表格，然后应用程序将电子邮件作为 MSG 导出到文件系统中的目录树

我有一个带有按钮的功能区，该按钮为已发送的电子邮件设置标志（用户属性），以便插件知道必须保存哪封电子邮件：

Private Sub Button1_Click(sender As Object, e As RibbonControlEventArgs) Handles Button1.Click
    Dim oProperties As Outlook.UserProperties
    Dim oProperty As Outlook.UserProperty


    oMail = Globals.ThisAddIn.Application.ActiveInspector.CurrentItem


    If Not oMail Is Nothing Then

        oProperties = oMail.UserProperties
        oProperty = oProperties.Add("SALVARAPIGES", Microsoft.Office.Interop.Outlook.OlUserPropertyType.olYesNo)
        oProperty.Value = True
        oMail.Save()
        oMail.Send()
    Else
        MsgBox("Err")
        Exit Sub
    End If
End Sub

在插件启动中，我有（sn-p）：

Private Sub ThisAddIn_Startup() Handles Me.Startup
    Dim sentItems As Outlook.Items
    Dim sentFolder As Outlook.Folder
    Dim paisapiges As String
    Dim aux As String()
    Dim ns As Microsoft.Office.Interop.Outlook.NameSpace

    apigesIsLoaded = True

    'adiciono um trigger para que sempre que for enviado um email e for do tipo SALVARAPIGES, ele fará o tratamento de salvar o email.
    sentFolder = Application.Session.GetDefaultFolder(Outlook.OlDefaultFolders.olFolderSentMail)
    sentItems = sentFolder.Items
    AddHandler sentItems.ItemAdd, AddressOf itemadd

还有我的 itemadd 例程：

Sub itemadd(ByVal NewEmailItem As Object)
    Dim oProperties As Outlook.UserProperties
    Dim salvaApiges As Boolean
    Dim sentMessageItem As Outlook.MailItem = CType(NewEmailItem, Outlook.MailItem)
    Dim mainForm As New formSalvarApiges()

    salvaApiges = False
    If Not sentMessageItem Is Nothing Then
        oProperties = sentMessageItem.UserProperties
        For Each pr As Outlook.UserProperty In oProperties
            If pr.Name = "SALVARAPIGES" Then
                salvaApiges = True
                Exit For
            End If
        Next

        If salvaApiges Then
            mainForm.txtAssunto.Text = sentMessageItem.Subject
            mainForm.sAction = "Acao01"
            mainForm.sEntryId = sentMessageItem.EntryID
            mainForm.ShowDialog()
            mainForm.Close()
        End If
    End If
End Sub

您可以看到，只要电子邮件具有此“SALVARAPIGES”用户属性，就必须将其保存到目录树中的 MSG 中。但是一半的用户说这不起作用（表格没有弹出），但是每当我测试它时，它就起作用了。我对 VSTO 及其背后的所有概念都很陌生……谁能指出我的方向？

我尝试过使用 NameSpace.SendAndReceive 方法，但他们一直在抱怨。

提前致谢！

Answer 1

引发事件的对象 (sentItems) 被声明为局部变量。一旦 GC 启动，它就会被释放并且不会引发更多事件。在类级别声明变量以确保它保持活动状态。

Answer 2

你需要在类级别声明源对象，以防止它被垃圾收集器刷掉：

Dim sentItems As Outlook.Items

Private Sub ThisAddIn_Startup() Handles Me.Startup
 Dim sentFolder As Outlook.Folder
 Dim paisapiges As String
 Dim aux As String()
 Dim ns As Microsoft.Office.Interop.Outlook.NameSpace

 apigesIsLoaded = True

 'adiciono um trigger para que sempre que for enviado um email e for do tipo SALVARAPIGES, ele fará o tratamento de salvar o email.
 sentFolder = Application.Session.GetDefaultFolder(Outlook.OlDefaultFolders.olFolderSentMail)
 sentItems = sentFolder.Items
 AddHandler sentItems.ItemAdd, AddressOf itemadd