1 增加應用      Microsoft.Office.Interop.Excel
        2 引用名稱空間  using Excel = Microsoft.Office.Interop.Excel;
        /// <summary>
        /// If the supplied excel File does not exist then Create it
        /// </summary>
        /// <param name="FileName"></param>
        private void CreateExcelFile(string FileName)
        {
            //create
            object Nothing = System.Reflection.Missing.Value;
            var app = new Excel.Application();
            app.Visible = false;
            Excel.Workbook workBook = app.Workbooks.Add(Nothing);
            Excel.Worksheet worksheet = (Excel.Worksheet)workBook.Sheets[1];
            worksheet.Name = "Work";
            //headline
            worksheet.Cells[1, 1] = "FileName";
            worksheet.Cells[1, 2] = "FindString";
            worksheet.Cells[1, 3] = "ReplaceString";

            worksheet.SaveAs(FileName, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Excel.XlSaveAsAccessMode.xlNoChange, Type.Missing, Type.Missing, Type.Missing);
            workBook.Close(false, Type.Missing, Type.Missing);
            app.Quit();
        }

        /// <summary>
        /// open an excel file,then write the content to file
        /// </summary>
        /// <param name="FileName">file name</param>
        /// <param name="findString">first cloumn</param>
        /// <param name="replaceString">second cloumn</param>
        private void WriteToExcel(string excelName,string filename,string findString,string replaceString)
        {
            //open
            object Nothing = System.Reflection.Missing.Value;
            var app = new Excel.Application();
            app.Visible = false;
            Excel.Workbook mybook = app.Workbooks.Open(excelName, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing);
            Excel.Worksheet mysheet = (Excel.Worksheet)mybook.Worksheets[1];
            mysheet.Activate();     
            //get activate sheet max row count
            int maxrow = mysheet.UsedRange.Rows.Count + 1;
            mysheet.Cells[maxrow, 1] = filename;
            mysheet.Cells[maxrow, 2] = findString;
            mysheet.Cells[maxrow, 3] = replaceString;
            mybook.Save();
            mybook.Close(false, Type.Missing, Type.Missing);
            mybook = null;
            //quit excel app
            app.Quit();
        }