首先，在我的Page1控件中聲明的變量：private PPt.Presentation oPPPresentation = null;    private PPt.Application oPPApplication = null;    private PPt.SlideShowWindow oPPslideShow;    private PPt.Slide oPPSlide;    private Object oDocument;我目前有一個webBrowser控件（稱為powerPointBrowser1），該控件顯示通過字符串傳遞的PowerPoint：public Page1()    {        InitializeComponent();        powerPointBrowser1.Navigate(strFileName);        powerPointBrowser1.LoadCompleted += powerPointBrowser1_LoadCompleted;    }這是我的powerPoint1Browser_LoadCompleted方法：private void powerPointBrowser1_LoadCompleted(object sender, NavigationEventArgs e)    {        oDocument = powerPointBrowser1.Document;        oPPPresentation = (PPt.Presentation)oDocument;        oPPApplication = oPPPresentation.Application;    }現(xiàn)在我的問題是：如何在Page1ViewModel中獲取LoadCompleted方法，以便可以訪問VM中的oDocument？