[C#]将数据写入已存在的excel文件

测试如下（xls/xlsx）：

 　　     //将数据写入已存在Excel
         public static void writeExcel(string result, string filepath)
         {
             //1.创建Applicaton对象
             Microsoft.Office.Interop.Excel.Application xApp = new 

             Microsoft.Office.Interop.Excel.Application();

             //2.得到workbook对象，打开已有的文件
             Microsoft.Office.Interop.Excel.Workbook xBook = xApp.Workbooks.Open(filepath,
                                   Missing.Value, Missing.Value, Missing.Value, Missing.Value,
                                   Missing.Value, Missing.Value, Missing.Value, Missing.Value,
                                   Missing.Value, Missing.Value, Missing.Value, Missing.Value);

             //3.指定要操作的Sheet
             Microsoft.Office.Interop.Excel.Worksheet xSheet = (Microsoft.Office.Interop.Excel.Worksheet)xBook.Sheets[];

             //在第一列的左边插入一列  1:第一列
             //xlShiftToRight:向右移动单元格   xlShiftDown:向下移动单元格
             //Range Columns = (Range)xSheet.Columns[, System.Type.Missing];
             //Columns.Insert(XlInsertShiftDirection.xlShiftToRight, Type.Missing);

             //4.向相应对位置写入相应的数据
             xSheet.Cells[Column(列)][Row(行)] = result;

             //5.保存保存WorkBook
             xBook.Save();
             //6.从内存中关闭Excel对象

             xSheet = null;
             xBook.Close();
             xBook = null;
             //关闭EXCEL的提示框
             xApp.DisplayAlerts = false;
             //Excel从内存中退出
             xApp.Quit();
             xApp = null;
         }