展望2007+鑄造Application.ActiveExplorer.Selection.Item到Outlook.mailItem時TypeOf運算項目= Outlook.mailItem

Question

採取以下前景VBA：

Sub FileEmails() 
    Dim myOlExp As Outlook.Explorer 
    Dim myOlSel As Outlook.Selection 

    Set myOlExp = Application.ActiveExplorer 
    Set myOlSel = myOlExp.Selection 

    If myOlSel.Count = 0 Then 
     MsgBox "No objects selected." 
    Else 
     For Each SelectedItem In myOlSel 
      If (TypeOf SelectedItem Is Outlook.mailItem) Then 
       Dim mailItem As Outlook.mailItem 
       Set mailItem = SelectedItem 
       itemMessage = "The item is an e-mail message. The subject is " & mailItem.Subject & "." 
       mailItem.Display (False) 
      ElseIf (TypeOf SelectedItem Is Outlook.contactItem) Then 
       Dim contactItem As Outlook.contactItem 
       Set contactItem = SelectedItem 
       itemMessage = "The item is a contact. The full name is " & contactItem.Subject & "." 
       contactItem.Display (False) 
      ElseIf (TypeOf SelectedItem Is Outlook.AppointmentItem) Then 
       Dim apptItem As Outlook.AppointmentItem 
       Set apptItem = SelectedItem 
       itemMessage = "The item is an appointment." & apptItem.Subject & "." 
      ElseIf (TypeOf SelectedItem Is Outlook.taskItem) Then 
       Dim taskItem As Outlook.taskItem 
       Set taskItem = SelectedItem 
       itemMessage = "The item is a task. The body is " & taskItem.Body & "." 
      ElseIf (TypeOf SelectedItem Is Outlook.meetingItem) Then 
       Dim meetingItem As Outlook.meetingItem 
       Set meetingItem = SelectedItem 
       itemMessage = "The item is a meeting item. The subject is " & meetingItem.Subject & "." 
      End If 
     Next SelectedItem 

     expMessage = expMessage & itemMessage 
     MsgBox (expMessage) 
    End If 

End Sub 

如果我選擇在我的收件箱幾個項目並運行此代碼，它成功地識別出的SelectedItem是Outlook.mailItem，但我得到試圖投的SelectedItem到Outlook.MailItem（即使將typeof參數返回TRUE）時，出現以下錯誤：

Object variable or with block variable not set 

我怎麼能執行此投？我基於以下.NET示例代碼（這使得使用TryCast的）：

http://msdn.microsoft.com/en-us/library/ms268994.aspx

Answer 1

我沒有測試你的代碼，但這裏有幾個點是可能的幫助。

Outlook VBA與VB.NET不一樣。 VB.NET是後代，有很多改進。

其中一項改進是您可以在塊級別聲明變量。對於VBA，變量只能在模塊或例程級別聲明。我不知道如果在循環中重新聲明變量會發生什麼情況，所以將所有Dim語句移到頂部。

VB.NET不使用SET。 VBA需要對象的SET，所以試試Set mailItem = SelectedItem。