尝试这个.

       app.DisplayAlerts = false;
        wb.SaveAs(@"C:\1\myExcel.xls", Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Excel.XlSaveAsAccessMode.xlNoChange, Type.Missing, Type.Missing, Type.Missing,
                    Type.Missing, Type.Missing);
        workbook.Close();
        app.Quit();