HttpContext.Current.Session Is Throwing Exception In Business Class
Sep 8, 2010
In our application we have to access session objects in business class. We are using HttpContext.Current.Session to get the session value. In some cases it returns the value but mostly its throwing a null reference exception(Object reference not set to an instance of an object). We have the following code Try
If HttpContext.Current.Session("Username") IsNot Nothing then
' Statements to be executed
End If
Catch ex As Exception
'Log to db
End Try
Here HttpContext.Current.Session("Username") is mostly throwing an exception "Object reference not set to an instance of an object" While debugging we found that HttpContext.Current itself is nothing.
i'm using an example in which i can fake the session.It's for use in a unittest of a mvc controller.In the test i create a controller and then i do this:
FakeHttpContext httpctx = new FakeHttpContext(null,null,null,null,mSessionItems ); ControllerContext ctx2 = new ControllerContext(httpctx,new RouteData(), target);
here mSessionItems is my session and target is my instance of a controller,and indeed, when i'm in a controller reading this.ControllerContext.HttpContext.Session, i have a session, great!but.... i also read the session outside the controller, and there i use HttpContext.Current.Session, and that is null (or actualy, the HttpContext.Current is null).
Is there room for issue in the following code in terms of multiple users of the same web application? I mean, I know that a purely static string will be shared across all sessions for a single ASP.NET application, but since this explicitly refers to the Current.Session, even though it is static it seems like it would always refer to the session instance of the "current user." But an error is happening that could be explained by everyone sharing the current value of Mode and thus the most recent change overwriting everyone else's mode value. (As a background: This string is in a Helpers class that is used throughout the application. I do not want to make references to Session["Mode"] throughout the application and do not want to have to pass Session["Mode"] in every method call from an aspx.cs page.)
public static string Mode { get { var value = HttpContext.Current.Session["Mode"]; return (value ?? string.Empty).ToString(); } set { HttpContext.Current.Session["Mode"] = value; } }
I am searching to find a way to read and write on session data but with out having the HttpContext.Current.Why I won to do that ?, because I wish to make some action with the user Session after the page have been close and unloaded. For example, a user load and see a page, then I create a thread to make some action and let user go. Inside this thread I like to read the session data, but in this case HttpContext.Current is not exist any more.
So is there a way to read Session Data knowing just the session id.I store my session inside an sql server, and I see them... its there on table ASPStateTempSessions . How can I read them "offline" and manipulate them ?
i'm storing in HttpContext.Current.Session current user, SiteUser is single-tone class that presents current active siteuser, and when he logged i'm creating new SiteUser() in controller and in constructor adding him to the session:
[Code]....
then, with every request to the server services i'm check is user available in session:
[Code]....
otherwise i'm generate non-auth-user exception and redirect him to the logon page. but sometimes HttpContext.Current.Session[sessionKey] is null, but HttpContext.Current.Session doesn't null and FormsAuthenticationTicket is available and Expired property is also false. can somebody help me, why HttpContext.Current.Session[sessionKey] can be null?UPDi have downloaded symbol tables of source .NET Framework and set breakpoints at SessionStateItemCollection on changing collection items. and i resolved some mistakes:1) all collection items are null — "culture" is setting up after2) it happens at the session end eventi can't understand how it can be, because at web.config session timeout is set 20
I have various web pages that need to build up a URL to display or place it in an emitted email message. The code I inherited had this value for the name of the webserver in a Public Const in a Public Class called FixedConstants. For example:
Public Const cdServerName As String = "WEBSERVERNAME"
Trying to improve on this, I wrote this:
Public Class UIFunction Public Shared myhttpcontext As HttpContext Public Shared Function cdWebServer() As String Dim s As New StringBuilder("http://") Dim h As String h = String.Empty Try h = Current.Request.ServerVariables("REMOTE_HOST").ToString() Catch ex As Exception Dim m As String m = ex.Message.ToString() 'Ignore this should-not-occur thingy End Try If h = String.Empty Then h = "SomeWebServer" End If s.Append(h) s.Append("/") Return s.ToString() End Function
I've tried different things while debugging such as HttpContext.Current.Request.UserHostName and I always get an empty string which pumps out my default string "SomeWebServer". I know Request.UserHostName or Request.ServerVariables("REMOTE_HOST") works when invoked from a page but why does this return empty when invoked from a called method of a class file (i.e. UIFunction.vb)?
We have a web site which implements a central HttpSessionState management in App_Code like this:
[code]...
All of this worked fine ultil we needed to implement a time consuming process in a new thread... In the second thread HttpContext.Current.Session is null (we know its because the current context its different between threads) so everything fails :
Investigating we found that you could pass the session from one thread to another like this:
I'm using VS2010 and created a simple asp. web forms application, using Development Server to test it. I try to store user data - queried from sql server - in the session, since I don't want to access database in every request. I'm using the 'Application_AuthenticateRequest' and the 'Session_Start' methods.
First round:
AuthenticateRequest called. The following code ran:
[Code]....
The _current variable is a private static field published through a static property. In the first round the Session is null, and I think it's ok because the Session_Start not called yet. The Session_Start looks like this:
In the next round the Session_Start is not called of course but in the AuthenticateRequest I can't access to the session. The HttpContext.Current.Session is null and the this.Session reference throw a HttpException says the "Session state is not available in this context".
However I can access the Session from any of the page_load events but it's a bad practice I think that I put authentication every page_load.
I created an AutocompleteExtender web service. I am getting a Object reference not set error in the peice of the code where I am referring to System.Web.HttpContext.Current.Session. Does anyone know why this is. And I am checking to see if it is != null before I reference it. But it crashes. Is there another way to pass another parameter to the web service?
I have a profile object in session with profile information for the currently logged in user. I wand to be able to inject it into my business classes so I can do validation etc in them without having to pass it in the parameter list in every method.
I have tried something like this in my ninject module:
Profile profile = HttpContext.Current.Session["Profile"] as Profile; Bind<Profile>().ToConstant(profile).InTransientScope();
However it blows up with null reference when I do Kernel.Get() in my aspx. The BusinessObject takes a profile via the constructor. If I hard code the profile instead of using the HttpContext then everything seems to work. Not sure if ToConstant is the way to go, I am really looking for something that will get evaluated every time a new BusinessObject is created.
UPDATE
It seems that asking for injection to happen on a page level object inline is too soon for the session collection to be available. If I move in the Kernel.Get call to Page_Load it works just fine.
I built a base controller class inherits from Controller class to add some custom behavior to all controllers which will inherit from this base class.
My issue is when I try to access HTTPContext and Session objects in my custom base class, they are always null.
Am I doing something wrong or need missing something?
My custom base class definition:
public class ApplicationControllerBase : Controller
controllers classes definition:
public class HomeController : ApplicationControllerBase
using ASP.NET MVC 1, .NET 3.5.
UPDATE:
It seems the issue is I try to access HTTPContext in the constructor while HTTPContext is not ready yet, I tried it in the OnActionExecuted event handler and it works fine.
My question is what is the best place to access Session object in my custom controller class, that will guarantee executing my code with all controllers.
I have a static class with serveral static methods. In these methods, I'm trying to access the current thread's context using HttpContext.Current. For example:
var userName = HttpContext.Current.User.Identity.Name;
However, when I do that, I receive a NullReferenceException, the infamous "Object reference not set to an instance of an object."
What is the point of throwing an exception? It it anyways going to be caught in the Global.asax Application_Error method.
Lets say in the following code we throw an exception.
try { using (var dc = GetDataContext()) { // We are doing some data inserts here. } catch ( Exception ex) { throw ex; }
My Question: Even if we do not use try catch and throw here, any exception which will be raised here will be caught inside Application_Error method in Global.asax. Then what is the point of try, catch and throw in this case?
I need my linq to sql datacontext to be available across my business/data layer for all my repository objects to access. However since this is a web app, I want to create and destroy it per request. I'm wondering if having a singleton class that can lazily create and attach the datacontext to current HttpContext would work. My question is: would the datacontext get disposed automatically when the request ends? Below is the code for what I'm thinking. Would this accomplish my purpose: have a thread-safe datacontext instance that is lazily available and is automatically disposed when the request ends?
public class SingletonDC { public static NorthwindDataContext Default { get { NorthwindDataContext defaultInstance = (NorthwindDataContext)System.Web.HttpContext.Current.Items["datacontext"]; if (defaultInstance == null) { defaultInstance = new NorthwindDataContext(); System.Web.HttpContext.Current.Items.Add("datacontext", defaultInstance); } return defaultInstance; } } }
I have an asp.net application with separate classes for business logic and database interaction and then of course the UI. I am building a form to add a widget to a widget list table in the database. My UI collects the information and submits it to the business class. I'm going to write the business class to first double check that the widget has a name (I know I should do this in UI with validation, and I will, but this is just in case validation is forgotten) and if it does, go ahead and send the information to the database class. The database class will then attempt to write the info to the correct table using a try catch finally block. Any errors caught here are logged and then rethrown so I can inform the user. So, knowing that my database class may rethrow an error, my business class code will also be written in a try catch finally block.
So at this point I have a number of possible outcomes that I want to inform the user via the UI:
1) Everything was fine and the widget was added.
2) Something happened with the database write and the user should try again later.
3) The user forgot to name the widget.
My question is: should I write my UI in a try catch block and then throw a custom Exception with an Exception.Message in the business layer if anything goes wrong, or just have my business logic return a string that is the message? I'll want to know if the process was successful or not, because I'll want to format the actual message differently, so I'd have to use if...elseif to determine if the message was bad or not.
It seems like throwing a custom Exception in the business layer may be a good way to tell the UI something bad happened. If the UI doesn't catch anything then of course the operation was successful. Then again throwing an exception for missing data seems a bit hefty.
I am using AjaxToolkit 4.0 which suggests to use ToolkitScriptManager in place of ScriptManager. But when I am using ToolkitScriptManager, it throws javascript exception when Page_ClientValidate() in called from javascript. However, this error is not coming when ScriptManager is used. Can anybody tell me how to make Page_ClientValidate() run when using ToolkitScriptManager?
Now it doesn't throw any exception, it executes fine but receiver does not receive any mail in his inbox. How can I fix this? Edit - This is the stack trace im getting.................
I am having this strange case, at first time when the page loades, everything goes fine. But as soon as I click on any link which makes any ajax request, after that, I get this error while trying to read the configuration."System.Configuration.ConfigurationManager.ConnectionStrings' threw an exception of type 'System.Web.HttpException"I am using asp.net mvc 1.0
then i insert an item to the top of list (at zero index):
Code:
protected void Title_DataBound(object sender, EventArgs e) { var item = (RadComboBox)sender; item.Items.Insert(0, new RadComboBoxItem("Select title...", "0")); }
It works perfect but, IF the Title field is zero and you Click EDIT LinkButton it throws an exception: Selection out of range Parameter name: value I would say that it's expected as zero index does not exist at the moment when i click edit button. I bind the combo from within RadGrid1_ItemCreated event.
