EggHeadCafe

While I'm helping the Folks on asp.net forums, I noticed that there is a lot of develoeprs trying to access the Http Session in Page Constructor !
Most of them used this to Implement a kind of Secured Base Page  that checks the session value ,and if its missing , it will redirect to login or whatever page.
some of them write this Class :

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

    public AdminSecuredPage()
    {
        if (Session["AdminUser"] == null) {
            Response.Redirect("~/login.aspx");
        }

    }
}
Note that the above class will throws HttpException , 
which tells :

"Session state can only be used when enableSessionState is set to true, either in a configuration file or in the Page directive. Please also make sure that System.Web.SessionStateModule or a custom session state module is included in the <configuration> ..."
 
 well the above exception will be thrown because the session is not ready when the Page constructor was called .
 
The Solution : 
One solution is to Move the Code from Page Constructor to  Page_init , Note that the page_init for this class will be called before the the Page_init of its Sub Page Class,
so you can check the Session value as follows:

public class AdminSecuredPage : System.Web.UI.Page
{
    public AdminSecuredPage()
    {}
   
    protected override void OnInit(EventArgs e)
    {
        // if the user is not Admin , redirect to Login Page
        if (Session["AdminUser"] == null)
            Response.Redirect("~/login.aspx");

        // this needed to initialize its base page class 
        base.OnInit(e);
    }
} 
 Hope This can help some one there ...
 and please ,if anyone has a better or other solutions , i will be happy to hear that ...

 
Best Regards,
Anas Ghanem