Why my session variables are getting empty?

[ronchese]

I'm noticing this since I started developing a website project: my session variables are getting empty!
I did a real easy test, and I checked my session variable is getting empty!! What is happening?

For example (VS2005, IE6/7, running in filesystem):

- In the Page_load of page1.aspx:
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArg s) Handles Me.Load
Throw New Exception("Erro r is thrown")
End Sub
- Then, I catch this on global.asax:
Sub Application_Err or(ByVal sender As Object, ByVal e As EventArgs)
'get current context
Dim ctxContext As HttpContext = HttpContext.Cur rent
If ctxContext Is Nothing Then Exit Sub

'get last error
Dim ex As Exception = ctxContext.Serv er.GetLastError ()
Session("LastEx ception") = ex.Message

'redict to error page
Response.Redire ct("../Other/ErrorPage.aspx" )
End Sub
- Finally, in the errorpage.aspx:
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArg s) Handles Me.Load
lblMessage.Text = Session("LastEx ception") '<-- The session is empty!!
End Sub
There are other situations the same problems also appear. For example, I'm setting an object to session via a shared class and when I gonna get that object again, its empty. In question of less a minute!

Is there any issue with session variables happening in .NET?

Cesar

[marss]

ronchese (a) wrote:

- Then, I catch this on global.asax:
Sub Application_Err or(ByVal sender As Object, ByVal e As EventArgs)
'get current context
Dim ctxContext As HttpContext = HttpContext.Cur rent
If ctxContext Is Nothing Then Exit Sub

'get last error
Dim ex As Exception = ctxContext.Serv er.GetLastError ()
Session("LastEx ception") = ex.Message

'redict to error page
Response.Redire ct("../Other/ErrorPage.aspx" )

Normal request life cycle: Application_Acq uireRequestStat e Page
Handlers Application_Rel easeRequestStat e

Session state restored for persistence at
"Application_Ac quireRequestSta te" and returned to persistence at
"Application_Re leaseRequestSta te". If you do not capture exception
within page event handler then it interrupts normal request life cycle.
(Session is not saved to persistent storage between requests). When
you call Responce.Redire ct you initiate new request without saving
changes made for Session.
So,
1.You can capture exception in page event handler:
protected void Page_Load(objec t sender, EventArgs e)
{
try
{
//throw exception
}
catch(Exception ex)
{
//process exception
}
}
2.You can use Server.Transfer instead of Responce.Redire ct. This method
does not initiate new request, but it trasfers execution to another
page.
3.If you want to use Responce.Redire ct then don't save data in Session
but in Cache:
HttpContext.Cur rent.Cache["Error"] = Server.GetLastE rror();

Sorry, I use C# for examples because I am not good in Visual Basic.

[ronchese]

Got it, Thanks.
And I got your C# sample, I understand it enough. :^D

"marss" <ma***@ukr.netw rote in message
news:11******** **************@ 73g2000cwn.goog legroups.com...

>
ronchese (a) wrote:

>- Then, I catch this on global.asax:
Sub Application_Err or(ByVal sender As Object, ByVal e As EventArgs)
'get current context
Dim ctxContext As HttpContext = HttpContext.Cur rent
If ctxContext Is Nothing Then Exit Sub

'get last error
Dim ex As Exception = ctxContext.Serv er.GetLastError ()
Session("LastEx ception") = ex.Message

'redict to error page
Response.Redire ct("../Other/ErrorPage.aspx" )

Normal request life cycle: Application_Acq uireRequestStat e Page
Handlers Application_Rel easeRequestStat e

Session state restored for persistence at
"Application_Ac quireRequestSta te" and returned to persistence at
"Application_Re leaseRequestSta te". If you do not capture exception
within page event handler then it interrupts normal request life cycle.
(Session is not saved to persistent storage between requests). When
you call Responce.Redire ct you initiate new request without saving
changes made for Session.
So,
1.You can capture exception in page event handler:
protected void Page_Load(objec t sender, EventArgs e)
{
try
{
//throw exception
}
catch(Exception ex)
{
//process exception
}
}
2.You can use Server.Transfer instead of Responce.Redire ct. This method
does not initiate new request, but it trasfers execution to another
page.
3.If you want to use Responce.Redire ct then don't save data in Session
but in Cache:
HttpContext.Cur rent.Cache["Error"] = Server.GetLastE rror();

Sorry, I use C# for examples because I am not good in Visual Basic.