主页上有个登陆 但是不知道怎么保存!有些页面要登陆后才能访问!
using System;
using System.Data;
using System.Data.Sql;
using System.Data.SqlClient;

using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;


/// <summary>
/// CUserInfo 的摘要说明
/// </summary>
public class CUserInfo
{

    /// <summary>
    /// 用户ID，对应是在数据库里的Y_ID字段的值
    /// </summary>
    public static int UserID
    {
        get { return GetUserID() ; }
        set { System.Web.HttpContext.Current.Session["UserID"]= value;}
    }

   

    /// <summary>
    /// 用户名称,对应在数据库里的Y_Name字段的值
    /// </summary>
    public static string UserName
    {
        get { return (string)System.Web.HttpContext.Current.Session["UserName"]; }
        set { System.Web.HttpContext.Current.Session["UserName"] = value; }
    }

    /// <summary>
    /// 用户编号:对应在数据库里的Y_PassWord,也就是登陆的密码
    /// </summary>
    public static string UserPassWord
    {
        get { return (string)System.Web.HttpContext.Current.Session["UserPassWord"]; }
        set { System.Web.HttpContext.Current.Session["UserPassWord"] = value; }
    }
    /// <summary>
    /// 用户权限:对应在数据库里的Y_QuanXian
    /// </summary>
    public static string UserQuanXian
    {
        get { return (string)System.Web.HttpContext.Current.Session["UserQuanXian"]; }
        set { System.Web.HttpContext.Current.Session["UserQuanXian"] = value; }
    }
    /// <summary>
    /// 用户性别:对应在数据库里的Y_XingBie
    /// </summary>
    public static string UserSex
    {
        get { return (string)System.Web.HttpContext.Current.Session["UserSex"]; }
        set { System.Web.HttpContext.Current.Session["UserSex"] = value; }
    }
   
   
    public CUserInfo()
    {
        //
        // TODO: 在此处添加构造函数逻辑
        //
    }

    private static int GetUserID()
    {
        if (System.Web.HttpContext.Current.Session["UserID"] == null)
            return 0;
        else
            return (int)System.Web.HttpContext.Current.Session["UserID"];
    }

    /// <summary>
    /// 清空登陆的所有信息
    /// </summary>
    public static void ClearUserInfo()
    {
        UserID = 0;
        UserName = "";
        UserPassWord = "";
        UserQuanXian = "";
        UserSex = "";
    }

    /// <summary>
    /// 检测当前是否登陆成功了
    /// </summary>
    /// <returns>true,表示已经成功登陆了,false,表示没有登陆</returns>
    public static bool CheckLogin()
    {
        if (UserID == 0)
            return false;
        else
            return true;
    }

   
   
}

这个类不能写在 DAL 里面