给每个页面加上session判断

using System; 

using System.Data; 

using System.Configuration; 

using System.Linq; 

using System.Web; 

using System.Web.Security; 

using System.Web.UI; 

using System.Web.UI.HtmlControls; 

using System.Web.UI.WebControls; 

using System.Web.UI.WebControls.WebParts; 

namespace FuSession
{ 

public class JudgeSession : System.Web.UI.Page
    { 

        protected override void OnInit(EventArgs e)
        { 

            base.OnInit(e);

             if (Session.Keys.Count <= 0)
            {
                Response.Redirect("~/TiaoZh.htm", true);
            } 

            else

             { if (Session["UserId"] == null && Session["Qx"] == null && Session["Dept"] == null && Session["UserName"] == null && Session["QxType"]==null)
                {
                    Response.Redirect("~/TiaoZh.htm", true);
                }
            }
        }       
    }
}