如何在 Visual Studio Outlook 加载项中访问某些邮件项 properties/methods？

Question

我正在使用 Visual Studio 2013（目标 .NET 4）开发 Outlook (2010) 加载项。

某些 Outlook properties/methods 似乎不可用。

以下代码适用于 Outlook VBA。

Public Sub OutlookTest()

    'Dim oApp As New Outlook.Application  (NOT NEEDED FOR OUTLOOK VBA)
    Dim oExp As Outlook.Explorer
    Dim oSel As Outlook.Selection   ' You need a selection object for getting the selection.
    Dim oItem As Object             ' You don't know the type yet.    
        
    Set oExp = Application.ActiveExplorer 'Get the ActiveExplorer.
    Set oSel = oExp.Selection           ' Get the selection.

    For i = 1 To oSel.Count         ' Loop through all the currently .selected items
        Set oItem = oSel.Item(i)        ' Get a selected item.
        Call DisplayInfo(oItem)          ' Display information about it.
    Next i

End Sub

Private Sub DisplayInfo(oItem As Object)

    Dim strMessageClass As String
    Dim oMailItem As Outlook.MailItem

    ' You need the message class to determine the type.
    strMessageClass = oItem.MessageClass

    If (strMessageClass = "IPM.Note") Then          ' Mail Entry.
        Set oMailItem = oItem
        MsgBox oMailItem.Subject
        MsgBox oMailItem.EntryID
        MsgBox oMailItem.HTMLBody
        oMailItem.SaveAs "C:\Users\u001tb7\Desktop\New folder\testOL.msg", olMSG
    Else
            MsgBox "Pick something else"
        End If

    End Sub

当我在加载项中尝试与 Visual Studio 几乎相同的代码时：

Private Sub butSettings_Click(sender As Object, e As RibbonControlEventArgs) Handles butSettings.Click

    Dim oApp As New Outlook.Application
    Dim oExp As Outlook.Explorer
    Dim oSel As Outlook.Selection   ' You need a selection object for getting the selection.
    Dim oItem As Object             ' You don't know the type yet.

    oExp = oApp.ActiveExplorer      ' Get the ActiveExplorer.
    oSel = oExp.Selection           ' Get the selection.

    For i = 1 To oSel.Count         ' Loop through all the currently .selected items
        oItem = oSel.Item(i)        ' Get a selected item.
        DisplayInfo(oItem)          ' Display information about it.
    Next i

End Sub

Sub DisplayInfo(oItem As Object)

    Dim strMessageClass As String
    Dim oMailItem As Outlook.MailItem

    ' You need the message class to determine the type.
    strMessageClass = oItem.MessageClass

    If (strMessageClass = "IPM.Note") Then          ' Mail Entry.
        oMailItem = oItem
        MsgBox(oMailItem.Subject)
        MsgBox(oMailItem.EntryID)
        MsgBox(oMailItem.HTMLBody)      '<---FAILS
        oMailItem.SaveAs("C:\Users\u001tb7\Desktop\New folder\testVS.msg", Outlook.OlSaveAsType.olMSG)  '<---ALSO FAILS
    Else
        MsgBox("Pick something else")
    End If

End Sub

我在 MailItem.HTMLBody 和 MailItem.SaveAs 上收到错误，但在 MailItem.Subject 或 .EntryID 上没有收到错误。

这让我怀疑这与安全有关，因为我认为像 .HTMLBody 这样的属性是 'protected'，但 .EntryID 和 .Subject 不是。

错误是通用 COM 异常，没有提供任何详细信息：

An exception of type 'System.Runtime.InteropServices.COMException' occurred in MsgSave.dll but was not handled in user code

Additional information: Operation aborted (Exception from HRESULT: 0x80004004 (E_ABORT))

有什么方法可以让 Outlook 'trust' 我的 VS 代码（用于最终分发）？还是有什么不妥？

编辑：感谢以下两位！

而不是：

Dim oApp As New Outlook.Application

使用：

Dim oApp as Outlook.Application = Globals.ThisAddIn.Application

Answer 1

不要在 Outlook 加载项中使用 New Outlook.Application - 当您的加载项启动时，您会免费获得 Outlook.Application 对象。

Answer 2

certain outlook properties/methods seem to be unavailable

你说的是什么属性？能具体点吗？

正如 Dmitry 所建议的，您需要使用 VSTO 提供的应用程序属性。在这种情况下，您将避免出现安全提示或异常。通常，当您尝试从独立应用程序自动化 Outlook 时，您会遇到此类问题。 VSTO 提供的应用程序对象是受信任的，不会为安全属性或方法（例如，MailItem.Send）生成异常。您可以在 Outlook "Object Model Guard" Security Issues for Developers 文章中阅读更多相关信息。

如何在 Visual Studio Outlook 加载项中访问某些邮件项 properties/methods？

How to access certain mailitem properties/methods in a Visual Studio Outlook Add-In?

outlook

vba

outlook-addin

visual-studio-2013