session becoming automatically null

mayur pandit

7y13.3k.NET

getting below error :

An exception of type 'System.NullReferenceException' occurred in App_Code.xdxzpwdw.dll but was not handled in user code

Additional information: Object reference not set to an instance of an object.

description :

below code working fine in other classes but in one class session becommig null automatically.

I am passing post request using ajax and uploading image and deleting image also same time.

Kindly check below code. I did not understand why this problem is occuringexatly. Kindly help.

code details :

public object BL_product_InsertUpdate(tbl_product product)//BL_admin_userInsertUpdate

{

string message = string.Empty;

if (!string.IsNullOrEmpty(HttpContext.Current.Session["UserName"].ToString()))

{

}

6 Replies

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mayur pandit7y ago
Hi Jagnesh & sagar,

Thank you for help. I got solution. I have use upload handler for insert form data and upload and delete image.by default the handlers are not connected with the session. we need to add IRequiresSessionState. look into below code

using System.Web.SessionState;

public class UploadHandler : IHttpHandler, IRequiresSessionState {

}

url : https://stackoverflow.com/questions/14181408/httpcontext-current-session-is-null-in-ashx-file

Thank's

Regards,

Mayur
Jignesh Kumar7y ago
Hi Mayurm

If you are using Ajax call then please try this one top of your method

[WebMethod(EnableSession = true)]

Could you please try below link ?

https://forums.asp.net/t/1818306.aspx?Problem+to+Get+Session+Value+in+ASPX+After+Ajax
https://seejoelprogram.wordpress.com/2008/11/10/maintaining-aspnet-session-state-in-an-ajax-application/
Sagar Malde7y ago
Hi Mayur,

The reason why you are getting null reference error is -
The Default timeout for Session is of 20 minutes. Thus after 20 minutes the Session automatically becomes null
In your code you are using .toString() extension method which does not except null values. This extension is throwing the null reference error.
However if you want to ignore session value you can use
public object BL_product_InsertUpdate(tbl_product product)//BL_admin_userInsertUpdate
{
   string message = string.Empty;
   if (!string.IsNullOrEmpty(Convert.ToString(HttpContext.Current.Session["UserName"])))
   {
   }
}
Convert.ToString will never throw null reference error.
Also you can set your own timeout for sessions in web.config file
     "30">


The above code will set Session's timeout to 30 minutes.
mayur pandit7y ago
Thank you for reply Jingesh sir, Actually I have already use this session name in another class method. This session is working fine in another method. session name is same. I did not understand why this session name lost in this method. I have only posting the data and upload the image using ajax.
Jignesh Kumar7y ago
Hi Mayur,

Could you please check you Session["UserName"] name and plase make sure you have assigned before reach this method.?
mayur pandit7y ago
also check attached ziped image