从Word加载项调用Excel加载项

Question

我有一个Excel加载项wirtten由我。现在我想要一个Word加载项，它从一个接口公开的Excel加载项中调用一些函数：

在Excel中公开的类：

  [ComVisible(true)]
public interface IWordInterface
{
     string WordTest();
}
[ComVisible(true)]
[ClassInterface(ClassInterfaceType.None)]
public class WordInterface : IWordInterface
{
    public string WordTest()
    {
        return "Hello from ExcelToMath";
    }
}

在主要的Excel插件类中：

 protected override object RequestComAddInAutomationService()
    {
        if (Word == null)
            Word = new Excel_Integration.WordInterface();
        return Word;
    }

现在我尝试在Word加载项中调用它：

Excel.Workbook Wb=(Excel.Workbook)Marshal.BindToMoniker("E:\\Test.xlsx");
        Office.COMAddIns AddIns = Wb.Application.COMAddIns;
        object addInName = "ExcelToMath";
        Office.COMAddIn addIn = Wb.Application.COMAddIns.Item(ref addInName);
        IWordInterface utilities = (IWordInterface)addIn.Object;

最后一行：

        IWordInterface utilities = (IWordInterface)addIn.Object;

抛出异常

  

HRESULT：0x80004002（E_NOINTERFACE）

从excel中调用加载了类似代码时，它没有问题：

 Office.COMAddIns AddIns = Globals.ThisAddIn.Application.COMAddIns;
        object addInName = "ExcelToMath";
        Office.COMAddIn addIn = Globals.ThisAddIn.Application.COMAddIns.Item(ref addInName);

        Excel_Integration.IWordInterface utilities = (Excel_Integration.IWordInterface)addIn.Object;
        string s=utilities.WordTest();

BindToMoniker调用是成功的，因为我可以使用VSTO从Word更改Excel Workbook中的数据。

我会很感激任何建议。