将多语言设置为一个小型网站

Question

我正在将set multilang设置为一个小型网站，但我在母版页面有问题，母版页有多个下拉列表..

我的条件是：

1. 如果我在每个cs页面设置下拉提醒的语言
2. 在cs页面中，如果我更改语言，lang应该更改，在我的代码page_load函数中有提示下拉列表。

但我的实际问题是：
如果我使用lang选择登录，则会打开一个带有下拉列表提醒的cs页面。如果我在该页面中更改lang，则lang现在不会更改，再次选择相同的lang

这是我的代码，请帮助

country_master.cs

protected void Page_Load(object sender, EventArgs e)
{            
    DropDownList _navigationmenu1 = (DropDownList)Master.FindControl("DrpLangSelector1");
    Session["Lang"] = _navigationmenu1.SelectedValue;
    Response.Cache.SetCacheability(HttpCacheability.NoCache);

    //checked sessionexists or not
    if (Session["UserName"] == null || Session["AccessLevel"] == null)
    {
        Response.Redirect("CEFA_Login.aspx?sessionExpired=true", true);
    }

    // Set Menu Options
    Menu _navigationmenu = (Menu)Master.FindControl("NavigationMenu");
    Label lblUserNameRole = (Label)Master.FindControl("lblUserNameRole");
    objCommonFunctions.SetMenu(_navigationmenu, lblUserNameRole, Session["UserName"].ToString(), Session["AccessLevel"].ToString(), (bool)Session["isCEFALaunched"], (bool)Session["IsPartTypeAdmin"]);
    //gvCountry.HeaderRow.FindControl("Label1").

    if (!IsPostBack)
    {
        //DropDownList _navigationmenu1 = (DropDownList)Master.FindControl("DrpLangSelector1");
        //Session["Lang"] = _navigationmenu1.SelectedValue;
        _navigationmenu.Visible = true;

        this.GetCountryData();
    }

    ScriptManager scriptmngr = (ScriptManager)Master.FindControl("ScriptManger1");
    scriptmngr.RegisterPostBackControl(btnSubmitCountry);
    scriptmngr.RegisterPostBackControl(btnUpdate);
    Page.Form.Attributes.Add("enctype", "multipart/form-data");

    try
    {
        Thread.CurrentThread.CurrentCulture = new CultureInfo(Session["Lang"].ToString());
        res_man = new ResourceManager("CEFA.App_GlobalResources.CEFA", Assembly.GetExecutingAssembly());
        cul = Thread.CurrentThread.CurrentCulture;
        contryinfobig1.Text = res_man.GetString("CountryInformation", cul);
        countryinfobig.Text = res_man.GetString("CountryInformation", cul);
        lblCountry.Text = res_man.GetString("Country", cul);
        lblCurrencyCode.Text = res_man.GetString("CurrencyCode", cul);
        lblIsCEFALaunched.Text = res_man.GetString("IsCEFALaunched", cul);
        btnSubmitCountry.Text = res_man.GetString("Submit", cul);
        btnClearCountry.Text = res_man.GetString("Clear", cul);
        lblcountrylist.Text = res_man.GetString("CountryList", cul);
        lblMandatory.Text = res_man.GetString("IndicatesMandatoryInputValue", cul);
        //Label4.Text = res_man.GetString("IndicatesMandatoryInputValue", cul);

        gvCountry.HeaderRow.Cells[1].Text = res_man.GetString("Country1", cul);
        gvCountry.HeaderRow.Cells[2].Text = res_man.GetString("CurrencyCode1", cul);
        gvCountry.HeaderRow.Cells[3].Text = res_man.GetString("IsCEFALaunched1", cul);
        gvCountry.PagerSettings.FirstPageText = res_man.GetString("First", cul);
        gvCountry.PagerSettings.LastPageText = res_man.GetString("Last", cul);
        gvCountry.PagerSettings.NextPageText = res_man.GetString("Next", cul);
        gvCountry.PagerSettings.PreviousPageText = res_man.GetString("Prev", cul);

        // gvCountry.Columns[4].Text=res_man.GetString("IsCEFALaunched", cul);
        //((Label)gvCountry.Columns[4].Text = res_man.GetString("IsCEFALaunched", cul);
    }
    catch (Exception s)
    {
        Console.WriteLine(s);
    }

}

的Site.Master：

    protected void Page_Load(object sender, EventArgs e)
    {
         DrpLangSelector1.SelectedValue=Session["Lang"].ToString();
        // NavigationMenu.me

        //string x = NavigationMenu.SelectedValue.ToString();

        if (ConfigurationManager.AppSettings["RunEnvironment"] != "Production")
        {
            lblHeader.Text = "COMPONENT EVALUATION FAILURE ANALYSIS - " + ConfigurationManager.AppSettings["RunEnvironment"];
            lblHeader.ForeColor = System.Drawing.Color.MediumVioletRed;
        }
        int id1 = Session["AccessLevelId"].ToInt32();
         }
    }
    protected void Page_Init(object sender, EventArgs e)
    {

    }
    protected void NavigationMenu_MenuItemClick(object sender, MenuEventArgs e)
    {
        if (NavigationMenu.SelectedValue.ToString() == res_man.GetString("Logout", cul))
        {
            //Session["UserName"] = "";
            //Session["AccessLevel"] = "";
            Response.Redirect("CEFA_Login.aspx", false);
        }

        // MODIFICATION STARTS: To change all Master screen names in Menu, screen title and every where else to "Information"  | Modified By: Mithun Chikhalikar | Date: June 10, 2014
        //if (NavigationMenu.SelectedValue.ToString() == "Masters")
        if (NavigationMenu.SelectedValue.ToString() == res_man.GetString("Information", cul))
        // MODIFICATION ENDS: To change all Master screen names in Menu, screen title and every where else to "Information"  | Modified By: Mithun Chikhalikar | Date: June 10, 2014
        {
            DrpLangSelector1.SelectedValue = Session["Lang"].ToString();
            Response.Redirect("blank.aspx", false);
        }
        if (NavigationMenu.SelectedValue.ToString() == res_man.GetString("Reports", cul))
        {
            Response.Redirect("blank.aspx", false);
        }         
    }

    protected void upOnload(object sender, EventArgs e)
    {            
        Page.Header.Controls.Add(new LiteralControl("<script type='text/javascript' src='" + Page.ResolveUrl("Scripts/imagepanner.js") + "'></script>"));           
    }

    protected void DrpLangSelector1_SelectedIndexChanged(object sender, EventArgs e)
    {
        Session["Lang"] = DrpLangSelector1.SelectedValue;
        Session["Langindex"] = DrpLangSelector1.SelectedIndex;
        // string x = NavigationMenu.SelectedValue.ToString();
        int id1 = Session["AccessLevelId"].ToInt32();
        if (Session["Lang"] != null)
        {
            Thread.CurrentThread.CurrentCulture = new CultureInfo(Session["Lang"].ToString());
            res_man = new ResourceManager("CEFA.App_GlobalResources.CEFA", Assembly.GetExecutingAssembly());
            cul = Thread.CurrentThread.CurrentCulture;
            lblHeader.Text = res_man.GetString("COMPONENTEVALUATIONFAILUREANALYSISDevelopment", cul);
            int id = Session["Accessid2"].ToInt32();
       }
     } 
  }
}