测试如下（xls/xlsx）：

 

1 　　     //将数据写入已存在Excel 2         public static void writeExcel(string result, string filepath) 3         { 4             //1.创建Applicaton对象 5             Microsoft.Office.Interop.Excel.Application xApp = new  6  7             Microsoft.Office.Interop.Excel.Application(); 8  9             //2.得到workbook对象，打开已有的文件10             Microsoft.Office.Interop.Excel.Workbook xBook = xApp.Workbooks.Open(filepath,11                                   Missing.Value, Missing.Value, Missing.Value, Missing.Value,12                                   Missing.Value, Missing.Value, Missing.Value, Missing.Value,13                                   Missing.Value, Missing.Value, Missing.Value, Missing.Value);14 15             //3.指定要操作的Sheet16             Microsoft.Office.Interop.Excel.Worksheet xSheet = (Microsoft.Office.Interop.Excel.Worksheet)xBook.Sheets[1];17 18             //在第一列的左边插入一列  1:第一列19             //xlShiftToRight:向右移动单元格   xlShiftDown:向下移动单元格20             //Range Columns = (Range)xSheet.Columns[1, System.Type.Missing];21             //Columns.Insert(XlInsertShiftDirection.xlShiftToRight, Type.Missing);22 23             //4.向相应对位置写入相应的数据24             xSheet.Cells[Column(列)][Row(行)] = result;25 26             //5.保存保存WorkBook27             xBook.Save();28             //6.从内存中关闭Excel对象29 30             xSheet = null;31             xBook.Close();32             xBook = null;33             //关闭EXCEL的提示框34             xApp.DisplayAlerts = false;          35             //Excel从内存中退出36             xApp.Quit();37             xApp = null;38         }