获取当前文件路径或当前打开的文件路径Server.MapPath

//DataBackups文件夹，指在WEB页面根目录
System.Web.HttpContext.Current.Server.MapPath("DataBackups");

//../../DataBackups，指在web页面根目录往上两级的DataBackups文件夹

System.Web.HttpContext.Current.Server.MapPath("../../DataBackups");