How to check for a valid session?

deb1980 · March 16th, 2007, 11:15 AM

Hi,

How to check for a valid session?

Regards,
Debashis

dparsons · March 16th, 2007, 11:21 AM

...What is a valid session? A session that hasn't expired?

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deb1980 · March 16th, 2007, 11:27 AM

Hi,

Thanks for the reply.
Yep i understand that part. However i want to know when an user directly types a link on the address bar, the aspx page should first check for a valid user id else it should redirect the user back to the login page.

What I is:

<%
    If (Session("userid").ToString = "") Then
        Response.Redirect("default.aspx")
    End If
%>

Could you please help?

regards,
Debashis

dparsons · March 16th, 2007, 11:40 AM

Ok that should work? What is the problem you are having with the code?

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^^Modified text taken from gbianchi profile^^
================================================== =========
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================================================== =========
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================================================== =========

deb1980 · March 16th, 2007, 11:43 AM

I am getting an error:

Server Error in '/Accountsystem' Application.
--------------------------------------------------------------------------------

Object reference not set to an instance of an object.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.

Source Error:

Line 1: <%@ Page Language="VB" AutoEventWireup="false" CodeFile="Default.aspx.vb" Inherits="_Default" %>
Line 2: <%
Line 3: If (Session("userid").ToString = "") Then
Line 4: Response.Redirect("default.aspx")
Line 5: End If

Previously to store data in session, I used:

Session("userid") = rs(0)

---
Best regards,

Debashis

dparsons · March 16th, 2007, 11:52 AM

Ahh. You can try 3 different methods.

Method 1:
If Session("userid") is Nothing then
Response.Redirect("default.aspx")
End If

Method 2
If Session("userID") = "" then
Response.Redirect("default.aspx")
End If

Method 3
If Session("userID") = "" OR Session("userID") is Nothing then
Response.Redirect("default.aspx")
End If

================================================== =========
Read this if you want to know how to get a correct reply for your question:
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^^Modified text taken from gbianchi profile^^
================================================== =========
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================================================== =========
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================================================== =========

deb1980 · March 16th, 2007, 11:59 AM

Thanks man - working cool!

---
Best regards,

Debashis

dparsons · March 16th, 2007, 12:03 PM

No problem glad it worked out for you.

================================================== =========
Read this if you want to know how to get a correct reply for your question:
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^^Took that from planoie's profile^^
^^Modified text taken from gbianchi profile^^
================================================== =========
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http://www.wiley.com/WileyCDA/WileyT...470131470.html
================================================== =========
Why can't Programmers, program??
http://www.codinghorror.com/blog/archives/000781.html
================================================== =========

Quick209 · March 24th, 2007, 06:27 PM

Just wanted to add to this topic about checking for nulls in C#. I found out it is very easy to use String.IsNullOrEmpty(your variable you are testing).

It will check to see if the object is null or empty and return true if is or false if not.