未能映射路径“/”。

带颜色的是出错语句
public partial class Controller_Setting_Menu_Edit : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            new EController().ChkMenuPower(Server.MapPath("."), Server.MapPath("/"));        }
    }
}下面是定义处代码
/// <summary>
    /// 判断用户是否有改页面权限
    /// </summary>
    /// <param name="FPath1">页面路径</param>
    /// <param name="FPath2">根目录路径</param>
    /// <returns></returns>
    public void ChkMenuPower(string FPath1,string FPath2)
    {
        //路径
        string FPath = FPath1.Replace(FPath2, "").Replace("\\", "/");        if (FPath.IndexOf("/") > -1)
        {
            FPath = FPath.Substring(FPath.IndexOf("/"));
        }        bool HavePower = false;        SH.Open();        SqlDataReader Dr;        int PowerId = 0;
        string SQL1 = "SELECT id FROM Setting_Menu WHERE Flag=0 AND FPath=@FPath";
        SqlParameter Parm1 = new SqlParameter("@FPath", SqlDbType.NVarChar);
        Parm1.Value = FPath;
        Dr = SH.ExecuteReader(SQL1, Parm1);
        if (Dr.Read())
        {
            PowerId = Dr.IsDBNull(0) ? 0 : Dr.GetInt32(0);
        }
        Dr.Close();
        Dr.Dispose();        if (PowerId > 0)
        {
            XParameter xParameter = new XParameter();
            string SQL2 = "SELECT 1 FROM Controller WHERE Flag=0 AND Account=@Account AND Pword=@Pword AND (FType=0 OR " + xParameter.IdInIds(PowerId, "Power") + ")";
            SqlParameter[] Parms2 = { 
                                    new SqlParameter("@Account",SqlDbType.NVarChar)
                                    ,new SqlParameter("@Pword",SqlDbType.NVarChar)
                                    };
            Parms2[0].Value = xeAccount.GetAccount("Controller", "Account");
            Parms2[1].Value = xeAccount.GetAccount("Controller", "Pword");            Dr = SH.ExecuteReader(SQL2, Parms2);            HavePower = Dr.HasRows;         //权限给定            Dr.Close();
            Dr.Dispose();
        }        SH.Close();        if (!HavePower)
        {
            //如果无菜单权限，则跳转到管理中心首页
            HttpContext.Current.Response.Redirect("/Controller");
            HttpContext.Current.Response.End();
        }
    }
请问要怎么改？