使用VSTO向Word文档中添加数学公式(2)

                Word.OMathFunction wdFunction = wdApplication.Selection 
                    .OMaths[1].Functions.Add(wdApplication.Selection.Range, 
                    Word.WdOMathFunctionType.wdOMathFunctionNary);                     
                Word.OMathNary wdNary = wdFunction.Nary; 
                wdNary.Char = 8721; 
                wdNary.Grow = false; 
                wdNary.SubSupLim = false; 
                wdNary.HideSub = false; 
                wdNary.HideSup = false; 
                //以下代码将数值填写入公式 
                Word.Selection wdSelection = wdApplication.Selection; 
                object unit = Word.WdUnits.wdCharacter; 
                object lu = Word.WdUnits.wdLine; 
                object count = 1; 
                object tcount = 3; 
                wdSelection.MoveLeft(ref unit, ref count); 
                wdSelection.TypeText("11"); 
                wdSelection.MoveLeft(ref unit, ref tcount); 
                wdSelection.TypeText("12"); 
                wdSelection.MoveDown(ref lu, ref count); 
                wdSelection.TypeText("13");