VSTO Outlook加载项 - 处理程序发送邮件不总是工作

Question

我有一个Outlook插件，处理某些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

我有一个功能区，带有一个按钮，用于为发送的电子邮件设置一个标志（userproperty）所以插件知道哪些邮件必须保存：

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 

在插件启动时，我有（摘录）：

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 

和我itemadd常规：

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 

正如您可以在电子邮件中包含此“SALVARAPIGES”用户属性时所看到的那样，它必须保存到目录树中的MSG中。但有一半的用户表示这不起作用（表格不是弹出窗口），但每当我测试它时，它都可以正常工作。我对VSTO及其背后的所有概念都很陌生......任何人都可以指出我的方向吗？

我已经尝试使用NameSpace.SendAndReceive方法，但他们不断抱怨。

在此先感谢！

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卡：

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