C#中Font转stdole.IFontDisp问题

public static stdole.IFontDisp GetIFontDisp(int size, string fontname, FontStyle fontStyle)
{
     string fontFamilyName = fontname;
     Font font = new Font(fontFamilyName, size, fontStyle);
     return ESRI.ArcGIS.ADF.COMSupport.OLE.GetIFontDispFromFont(font) as stdole.IFontDisp;
}