Calling OneNote GetHierarchy() from Silverlight Application

I have a Silverlight 4 out-of-browser, elevated trust application. I would like to use the OneNote 2010 object model to communicate with OneNote using the AutomationFactory and I'm not able to get the GetHierarchy() method of the Application to work. I know I have data in OneNote, because I can开发者_开发百科 call the method from a .NET application and get data back from it. The GetHierarchy() method returns null. Any suggestions?

class OneNoteAutomation
{
    dynamic oneNote;

    enum HierarchyScope
    {
        hsSelf = 0,
        hsChildren = 1,
        hsNotebooks = 2,
        hsSections = 3,
        hsPages = 4
    }

    public void GetHierarchy()
    {
        if (AutomationFactory.IsAvailable)
        {
            this.oneNote = AutomationFactory.CreateObject("OneNote.Application");

            var result = this.oneNote.GetHierarchy(
                string.Empty, 
                (int)HierarchyScope.hsNotebooks, 1);            
        }
    }
}

This is a known bug that calls with methods that have 'out' cannot be used in AutomationFactory - please see SL4 - AutomationFactory - Call method with 'out' parameters raise exception: 'Could not convert an argument for the call to...'

BTW, I'm not sure what you are trying to do with the 1 in your GetHierarchy call - that is the pointer to the string that will be filled with the XML of the chosen HierarchyScope enum. It should be a string out variable, instead of an integer - but regardless, it still won't work in SL4 due to the bug.