.Net操作Excel公式实现

//传入Excel公式，获取公式计算结果
private string GetValue(string formula)
        {
            string result = "";
            try
            {
                Object missing = System.Reflection.Missing.Value;
                Excel.Application excelApp = new Excel.Application();
                Excel.Workbooks wbooks = (Excel.Workbooks)excelApp.Workbooks;
                string path1 = AppDomain.CurrentDomain.BaseDirectory + ("UpFiles\") + "635236681202245225.xls";

                Excel.Workbook wbook = wbooks.Open(path1, missing, missing, missing, missing, missing, missing, missing, missing, missing, missing, missing, missing, missing, missing);
                excelApp.Visible = false;
                excelApp.DisplayAlerts = false;
                //s写入sheet1
                Excel.Worksheet wsheet = (Excel.Worksheet)wbook.Worksheets.get_Item(1);

                Excel.Range range = (Excel.Range)wsheet.Cells[1, 1];
                range.Formula = formula;
                //range = (Excel.Range)wsheet.Cells[1, 2];
                //range.Value2 = 5;
                //range = (Excel.Range)wsheet.Cells[1, 3];
                //range.Value2 = 123;
                wbook.Save();
                range = (Excel.Range)wsheet.Cells[1, 1];
                result = range.Value2.ToString();

                wbook.Close();
                wbooks.Close();
            }
            catch
            { }
            finally
            {
                Process[] myProcesses = Process.GetProcessesByName("Excel");
                foreach (Process myProcess in myProcesses)
                { myProcess.Kill(); }
            }
            return result;
        }