在MS Excel+VBA中检测WorkbookAddinInstall事件失败

我似乎无法使用Excel 2013检测WorkbookAddinInstall事件

我创建了一个Excel加载项，其中包含一个名为CexElevents的类模块，该类模块具有许多事件的简单子例程处理程序，如下所示

Private WithEvents XLApp As Application

Private Sub Class_Initialize()
    Set XLApp = Application
End Sub

Private Sub XLApp_NewWorkbook(ByVal Wb As Workbook)
    MsgBox "NewWorkbook" & Wb.Name
End Sub

Private Sub XLApp_WorkbookAddinInstall(ByVal Wb As Workbook)
    MsgBox "AddinInstall"
End Sub


Private Sub XLApp_WorkbookAddinUninstall(ByVal Wb As Workbook)
    MsgBox "AddinUnInstall"
End Sub

Private Sub XLApp_WorkbookOpen(ByVal Wb As Workbook)
    MsgBox "OpenWorkbook" & Wb.Name
End Sub

然后在我的加载项工作簿的ThisWorkbook模块中

Private ExcelEvents As CExcelEvents

Private Sub Workbook_Open()
    Set ExcelEvents = New CExcelEvents
End Sub

除了XLApp_WorkbookAddinInstall之外，所有这些处理程序都可以工作

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有人能看到我可能做错了什么吗？

似乎检测到了在安装我的加载项之后安装的任何加载项，但没有通知初始安装，这当然是我想要的

但是，在加载项的ThisWorkbook模块中放置以下子项确实提供了我需要的行为：

Private Sub Workbook_AddinInstall()
    MsgBox "An addin is being installed"
End Sub

Private Sub Workbook_AddinUninstall()
    MsgBox "An addin is being removed"
End Sub