session的问题

Question

null是不能ToString()的.要判断Session["name"]==null

Answer 1

一楼正解，要先判断是否==null

Answer 2

session为null的时候不能.tostring() 否则会出错
判断session[""]==""||session[""]==null即可

Answer 3

if(Session["name"] ==null || Session["name"].ToString()=="") 
                { 
                        Response.Write(" <script> alert('网页过期，请重新登陆！');window.close() </script> "); 
                } 

Answer 4

 if (Session["s"] != null)
{
            this.TextBox1.Text = Session["s"].ToString();
 }

Answer 5

if(Session["name"] ==null) 
                { 
                        if(Session["name"].ToString().Length>0)
                        {                         Response.Write(" <script> alert('网页过期，请重新登陆！');window.close() </script> "); 
                        }
                } 

Answer 6

if (Convert.ToString(Session["LoginID"]) == "" ||Convert.ToString(Session["LoginID"]) == null)
{
 Response.Redirect("../return.aspx");
}

Answer 7

Session["name"]==null
Session["name"]为null时是不能.ToString()

Answer 8

if(Session["name"].ToString()==string.Empty ¦ ¦Session["name"].ToString()=="") 
                { 
                        Response.Write(" <script> alert('网页过期，请重新登陆！');window.close() </script> "); 
                }