You mean you are using System.Web.HttpContext.Current.Session and it fails? Check if the problem is with Current or Session. It can depend on where you are trying to use that (for example you don't have an current http request when the application starts
or the session ends). Or it could be perhaps some kind of design flaw that causes the session variable you are reading to be null.
My personal preference is to hide session variables behind a facade so that I can load the value on demand.
No even using simple session also not working in class. Actually this is error handler and when I got some error on site it sends me a mail. In mail I need to log the user I'd of user. I created error by entering wrong page address and session exists at this
time
No even using simple session also not working in class. Actually this is error handler and when I got some error on site it sends me a mail. In mail I need to log the user I'd of user. I created error by entering wrong page address and session exists at this
time
Session might not exist for many reasons. However, using Session in a separate class is never recommended. Always pass the Session value to the class either in a constructor, method, or property.
There is no guarantee that session will exist and you should always be able to fetch the Session values. If you cannot then you have a design issue.
The only time you should see Session in a class is when you have static class that access Session values by strong names so you get intellisense within the project.
I debug all. I simply made a form and add session in variable on form load and then I run that form and change the url. it goes to global.asax and here I didn't find the session value. I added the session value in watch list and I found that when error
comes it says 'session' is not declared. It may be inaccessible due to its protection level.
I debug all. I simply made a form and add session in variable on form load and then I run that form and change the url. it goes to global.asax and here I didn't find the session value. I added the session value in watch list and I found that when error
comes it says 'session' is not declared. It may be inaccessible due to its protection level.
There are several global.asax events where Session is not available. Rather than us guessing how your code works, how about you post sample code that reproduces this issue.
Protected Sub Page_Load(sender As Object, e As EventArgs) Handles Me.Load
Session("MyName") = "ravikant"
End Sub
global.asax
Sub Application_Error(ByVal sender As Object, ByVal e As EventArgs)
'MsgBox(System.Web.HttpContext.Current.Session("MyName"))
Dim lastError As Exception = Server.GetLastError()
If (lastError IsNot Nothing AndAlso lastError.Message <> "File does not exist.") AndAlso (lastError.Message <> "Thread was being aborted") AndAlso (lastError.Message <> "The client disconnected.") Then
Dim xCl As New CommonClass
xCl.SendMail(lastError, HisIp)
End Sub
commonclass
Public Sub SendMail(ByVal i_oErr As Exception, ByVal ClientIp As String)
Try
--not getting session here
MsgBox(System.Web.HttpContext.Current.Session("MyName"))
Catch ex As Exception
end try
I'm not getting session value neither in global nor in class
The steps to reproduce the error are not very clear. Errors that happen before AcquireRequestState will not have Session as Session has not started yet.
After seeing your code I recommend you rethink the approach and use more robust exception handling.
Secondly, never do this.
Public Sub SendMail(ByVal i_oErr As Exception, ByVal ClientIp As String)
Try
--not getting session here
MsgBox(System.Web.HttpContext.Current.Session("MyName"))Catch ex As Exception
end try
Always pass Session values to another class via parameters.
Public Sub SendMail(ByVal i_oErr As Exception, ByVal ClientIp As String, ByVal MyName as String)
Never implement an empty Catch block!
Lastly, MsgBox pops up on the server and is not recommended for development.
Please read the docs for proper exception handling and exception logging.
2] after I load the form I get an error so it goes to global.asax then why I am not getting session variable here.
3] I am using msgbox on locally just to test the value
Again, we need code that actually runs and compiles to reproduce this issue. There is no indication how or when the exception is fired. Perhaps you are firing the exception right after setting Session and that is why Session is not working as expected.
I made a very simple test and cannot reproduce this issue. Session is clearly displayed in the Visual Studio Console.
Public Class CommonClass
Public Sub SendMail(ByVal i_oErr As Exception, ByVal ClientIp As String, ByVal MyName As String)
System.Diagnostics.Debug.WriteLine("Error Message: " & i_oErr.Message)
System.Diagnostics.Debug.WriteLine("ClientIp: " & ClientIp)
System.Diagnostics.Debug.WriteLine("MyName: " & MyName)
End Sub
End Class
Sub Application_Error(ByVal sender As Object, ByVal e As EventArgs)
Dim lastError As Exception = Server.GetLastError()
If (lastError IsNot Nothing AndAlso lastError.Message <> "File does not exist.") AndAlso (lastError.Message <> "Thread was being aborted") AndAlso (lastError.Message <> "The client disconnected.") Then
Dim xCl As New CommonClass
xCl.SendMail(lastError, "127.0.0.1", System.Web.HttpContext.Current.Session("MyName"))
End If
End Sub
Public Class ExceptionSessionTest
Inherits System.Web.UI.Page
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
If Not Page.IsPostBack Then
Session("MyName") = "ravikant"
End If
End Sub
Protected Sub Button1_Click(sender As Object, e As EventArgs)
Throw New Exception("This is a test!")
End Sub
End Class
Results
Exception thrown: 'System.Exception' in VbWebApplication.dll
An exception of type 'System.Exception' occurred in VbWebApplication.dll but was not handled in user code
This is a test!
Error Message: Exception of type 'System.Web.HttpUnhandledException' was thrown.
ClientIp: 127.0.0.1
MyName: ravikant
The thread 0x24fc has exited with code 0 (0x0).
The thread 0x6dd8 has exited with code 0 (0x0).
However, I still feel that you exception handling is very fragile and need to rethinking the design.
Well thank you mgebhard. I appreciate your patience with me. I will try to write the error handler as you described. I think I will get the user name by this way. Will try on live server and let you know. It seems that issue has been solved and also
I learnt a new way.
Member
44 Points
402 Posts
Read session value from class
Apr 08, 2019 11:01 AM|ravininave|LINK
All-Star
46250 Points
16886 Posts
Re: Read session value from class
Apr 08, 2019 11:06 AM|PatriceSc|LINK
Hi,
You mean you are using System.Web.HttpContext.Current.Session and it fails? Check if the problem is with Current or Session. It can depend on where you are trying to use that (for example you don't have an current http request when the application starts or the session ends). Or it could be perhaps some kind of design flaw that causes the session variable you are reading to be null.
My personal preference is to hide session variables behind a facade so that I can load the value on demand.
Member
44 Points
402 Posts
Re: Read session value from class
Apr 08, 2019 11:49 AM|ravininave|LINK
All-Star
44801 Points
19365 Posts
Re: Read session value from class
Apr 08, 2019 12:06 PM|mgebhard|LINK
Session might not exist for many reasons. However, using Session in a separate class is never recommended. Always pass the Session value to the class either in a constructor, method, or property.
There is no guarantee that session will exist and you should always be able to fetch the Session values. If you cannot then you have a design issue.
The only time you should see Session in a class is when you have static class that access Session values by strong names so you get intellisense within the project.
Member
44 Points
402 Posts
Re: Read session value from class
Apr 08, 2019 12:10 PM|ravininave|LINK
All-Star
46250 Points
16886 Posts
Re: Read session value from class
Apr 08, 2019 12:11 PM|PatriceSc|LINK
Maybe the null reference is not on what you think? Add a breakpoint so that you can inspect variables and make 100% sure about which variable is null.
Member
44 Points
402 Posts
Re: Read session value from class
Apr 08, 2019 08:04 PM|ravininave|LINK
I debug all. I simply made a form and add session in variable on form load and then I run that form and change the url. it goes to global.asax and here I didn't find the session value. I added the session value in watch list and I found that when error comes it says 'session' is not declared. It may be inaccessible due to its protection level.
All-Star
44801 Points
19365 Posts
Re: Read session value from class
Apr 08, 2019 08:10 PM|mgebhard|LINK
There are several global.asax events where Session is not available. Rather than us guessing how your code works, how about you post sample code that reproduces this issue.
Member
44 Points
402 Posts
Re: Read session value from class
Apr 08, 2019 08:14 PM|ravininave|LINK
test.aspx
Protected Sub Page_Load(sender As Object, e As EventArgs) Handles Me.Load Session("MyName") = "ravikant" End Subglobal.asax
Sub Application_Error(ByVal sender As Object, ByVal e As EventArgs) 'MsgBox(System.Web.HttpContext.Current.Session("MyName")) Dim lastError As Exception = Server.GetLastError() If (lastError IsNot Nothing AndAlso lastError.Message <> "File does not exist.") AndAlso (lastError.Message <> "Thread was being aborted") AndAlso (lastError.Message <> "The client disconnected.") Then Dim xCl As New CommonClass xCl.SendMail(lastError, HisIp) End Subcommonclass
Public Sub SendMail(ByVal i_oErr As Exception, ByVal ClientIp As String) Try --not getting session here MsgBox(System.Web.HttpContext.Current.Session("MyName")) Catch ex As Exception end tryI'm not getting session value neither in global nor in class
All-Star
44801 Points
19365 Posts
Re: Read session value from class
Apr 08, 2019 08:30 PM|mgebhard|LINK
The steps to reproduce the error are not very clear. Errors that happen before AcquireRequestState will not have Session as Session has not started yet.
After seeing your code I recommend you rethink the approach and use more robust exception handling.
Secondly, never do this.
Public Sub SendMail(ByVal i_oErr As Exception, ByVal ClientIp As String) Try --not getting session here MsgBox(System.Web.HttpContext.Current.Session("MyName")) Catch ex As Exception end tryAlways pass Session values to another class via parameters.
Public Sub SendMail(ByVal i_oErr As Exception, ByVal ClientIp As String, ByVal MyName as String)Never implement an empty Catch block!
Lastly, MsgBox pops up on the server and is not recommended for development.
Please read the docs for proper exception handling and exception logging.
https://docs.microsoft.com/en-us/aspnet/web-forms/overview/getting-started/getting-started-with-aspnet-45-web-forms/aspnet-error-handling
Member
44 Points
402 Posts
Re: Read session value from class
Apr 08, 2019 08:39 PM|ravininave|LINK
1] I think session has started on form load.
2] after I load the form I get an error so it goes to global.asax then why I am not getting session variable here.
3] I am using msgbox on locally just to test the value
All-Star
44801 Points
19365 Posts
Re: Read session value from class
Apr 08, 2019 08:59 PM|mgebhard|LINK
Again, we need code that actually runs and compiles to reproduce this issue. There is no indication how or when the exception is fired. Perhaps you are firing the exception right after setting Session and that is why Session is not working as expected.
I made a very simple test and cannot reproduce this issue. Session is clearly displayed in the Visual Studio Console.
Public Class CommonClass Public Sub SendMail(ByVal i_oErr As Exception, ByVal ClientIp As String, ByVal MyName As String) System.Diagnostics.Debug.WriteLine("Error Message: " & i_oErr.Message) System.Diagnostics.Debug.WriteLine("ClientIp: " & ClientIp) System.Diagnostics.Debug.WriteLine("MyName: " & MyName) End Sub End ClassSub Application_Error(ByVal sender As Object, ByVal e As EventArgs) Dim lastError As Exception = Server.GetLastError() If (lastError IsNot Nothing AndAlso lastError.Message <> "File does not exist.") AndAlso (lastError.Message <> "Thread was being aborted") AndAlso (lastError.Message <> "The client disconnected.") Then Dim xCl As New CommonClass xCl.SendMail(lastError, "127.0.0.1", System.Web.HttpContext.Current.Session("MyName")) End If End Sub<%@ Page Language="vb" AutoEventWireup="false" CodeBehind="ExceptionSessionTest.aspx.vb" Inherits="VbWebApplication.ExceptionSessionTest" %> <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head runat="server"> <title></title> </head> <body> <form id="form1" runat="server"> <div> <asp:Button ID="Button1" runat="server" Text="Button" OnClick="Button1_Click" /> </div> </form> </body> </html>Public Class ExceptionSessionTest Inherits System.Web.UI.Page Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load If Not Page.IsPostBack Then Session("MyName") = "ravikant" End If End Sub Protected Sub Button1_Click(sender As Object, e As EventArgs) Throw New Exception("This is a test!") End Sub End ClassResults
However, I still feel that you exception handling is very fragile and need to rethinking the design.
Member
44 Points
402 Posts
Re: Read session value from class
Apr 08, 2019 09:06 PM|ravininave|LINK
Well thank you mgebhard. I appreciate your patience with me. I will try to write the error handler as you described. I think I will get the user name by this way. Will try on live server and let you know. It seems that issue has been solved and also I learnt a new way.
Thank you mate.