State Management :: Casting Session Object To Generic List Fails?
Feb 27, 2011
i'm having a gridview with textboxes and i'm allowing user to enter all the textboxes and when submit button is clicked, I'm constructing the Object and adding all the rows to LIST class.,After that i'm putting that LIST elements in a session. Everything is fine, But when i try to cast the session object to LIST type and pass it to XML serialization, I cannot see the elements in the list and it is showing LIST as NULL. I can see the generated XML string with ROOT and my classname as attributes without no data.
I am trying to save the every date clicked in a List of Date using a session variable. I am getting a casting error ..."when casting a number the number must be less than infinity".
I need to cache System.Collection.Generic.List object with expiration time
var Root = from feed in feedhotel.Descendants(ota + "HotelContent") where (feed.Attribute("HotelCode") != null) select new xmlhotel() { }; return Root.ToList();
Is it possible to cache Root.ToList() for some time....
In Asp.net application. i cache a Linq to Xml result to a Cache object. when i cast the cache object back to generic list. i get the following exception.
[A]System.Collections.Generic.List`1[CarRentalAddress] cannot be cast to [B]System.Collections.Generic.List`1[CarRentalAddress]. Type A originates from 'mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' in the context 'LoadNeither' at location 'C:WINDOWSassemblyGAC_32mscorlib2.0.0.0__b77a5c561934e089mscorlib.dll'. Type B originates from 'mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' in the context 'LoadNeither' at location 'C:WINDOWSassemblyGAC_32mscorlib2.0.0.0__b77a5c561934e089mscorlib.dll'.
My code looks like this.
if (!Page.IsPostBack) { if (Cache["xml"] == null) { DataSet ds = new DataSet(); ds.ReadXml(HttpContext.Current.Server.MapPath("~/CarRentalAddress.xml")); var grid = (from d in ds.Tables[0].AsEnumerable() orderby d.Field<string>("City") where d.Field<string>("Enabled") == "1" select new CarRentalAddress { City = d.Field<string>("City"), HotelName = d.Field<string>("HotelName"), Address = d.Field<string>("Address"), EmailID1 = d.Field<string>("EmailID1"), EmailID2 = d.Field<string>("EmailID2") }).ToList(); Cache["xml"] = grid; totalrows = grid.Count().ToString(); grdAddress.DataSource = grid; grdAddress.DataBind(); } else { //Exception is thrown by this line var grid = (List<CarRentalAddress>)Cache["xml"]; totalrows = grid.Count().ToString(); grdAddress.DataSource = grid; grdAddress.DataBind(); } }
I have a generic handler in which I fill up a Session variable. I implemented the IRequiresSessionState interface, so it shouldn't be a problem.
In a given page, I want to display that value, but it seems like the value is always empty. Is it because the session that is accessed and written to in the handler isn't the same one that is used on this page?
In the handler, I used context.Session["EID"] = "somevalue";
edit: i found out what the issue is but I do not know how to solve it. It's because I have this Java applet which reads out an eID, calls the handler to store the data, but the session used by the applet is not the same as the session used by the browser... so how could I exchange this data in a safe way?
Okay, so I have a Generic IList of custom objects that I want to use as a datasource for a repeater.
[Code]....
In the WebForm inside the repeater, I place this code:
[Code]....
when I try to run it, I get the error "Unable to cast object of type 'System.Collections.Generic.List`1[MyCustomObject]' to type'MyCustomObject'. ". Which makes sense, really.
What's the best way round this? Is there any way I can get the direct cast working? I'm loath to have to create a custom list item that implements IBinding or something and bind that directly, as that'll mean a lot of legacy changes which may create further bugs. Or is there a better way?
I want to be able to persist data across a session but do this outside of the built-in session state object. Why is a long story that I will not go into here. I just need to know where I can put data other than in the session object that will persist across the specific session.
On my local machine I've got a website running which uses the login control to authenticate a user and write a formsauthentication ticket to the client (which is also on the same local machine). At the login process it stores a a small serializable userobject in a session object named Session["appuser"]. Now when I open FF and login to the website all is fine so far... But here's the thing I cannot for the life of me figure out...
When I open IE8 and login to the same website, the session object which was created in FF is completely overwritten with the one created in IE. I thought that every session is unique, but now I'm really starting to feel my knowledge of sessions is almost next to nothing... Is there anyone out there that could tell me why I'm seeing this.
I have a object of Class named "Employee" I need to store the object in the session. what happens if i do not serialize the object and store in the session.
I have a Authorizeclient.aspx.cs page where I set my session value.Authorizeclient.aspx is a blank page. HttpContext.Current.Session["nodeID"]="0". This session value changes from 0 or non zero which depends on the value returned by Database. If no value is returned I assign HttpContext.Current.Session["nodeID"]="0" as the default state else I assign HttpContext.Current.Session["nodeID"]=resolve(nodeID).ToString()
Till this part it works fine as expected. However, I have a requirement that I need to read the nodeID from Session in other application on the same server. I mean this application too is part of the root project where I initially created the Session and set it. The strange thing is the Session["nodeID"] in application gets null "SOMETIMES" Not always. I am trying to read the Session in Page_Load. Sometimes it works fine and sometimes it gets null. Moreover the session object do not die and I can see other keys like Session["Themes"] etc there. The session is in InProc mode and have 20 minutes timeout time.
I am stuck with the issue of concurrent access to Session object. Actually my problem is i m writing to session in frame1 and trying to access that same Session object at the same time in Frame2's Page. I know about the reader/writer lock. I made the enablesessionstate = readonly in the page where i m writing to session. its giving me strange behavior on IE and firefox.
Its working concurrently in IE8 ( means page2 is diplaying modified values while page1 is changing the session object) but does not work in Firefox even page load is not called untill function on page 1 completed. Either anyone can fix my issue with firefox or there is new solution to reader/writer lock so that i can read the session at the same time while writing.
I have a asp.net application where I am saving off into session the user privilege information. From a grid I am bring up a new window by using the window.open. It seems that it is whiping out the values in session. A temporary bandaid I have placed on it is to recall the database if the value is nothing to reset the user object. I have found all over the internet that this is an issue with the window.open in IE 7 and IE 8. Has anyone else run into this and able to actually fix it?
System.InvalidCastException was unhandled by user code
Message=Specified cast is not valid.
Source=App_Web_donate.aspx.cdcab7d2.wqdohvu3 StackTrace: at Donate.LoadUserDetails() in C:UsersSimonDesktopLocal SitesCats ProtectionNewDonate.aspx.vb:line 261 at Donate.btnDonate30_Click(Object sender, EventArgs e) in C:UsersSimonDesktopLocal SitesCats ProtectionNewDonate.aspx.vb:line 205 at System.Web.UI.WebControls.LinkButton.OnClick(EventArgs e) at System.Web.UI.WebControls.LinkButton.RaisePostBackEvent(String eventArgument) at System.Web.UI.WebControls.LinkButton.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) at System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) at System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
InnerException: I have made the important bits Bold I have the following code which is generating this error:
[Code]....
I am not entirely sure what is causing it. Its completley intermitent. I am storing all the details of a user filling in a form in a structure, and then assigning that structure to a session variable. This means if they page back, and then page forward again, I can pre-populate the form with the details they have already filled in for their conveinience by using the above code snippet. It appears that it works for a good minute, but if I leave the browser alone any longer than roughly 60 seconds, and then try and page forward to the form again, the exception will fire. While writing this post, the exception has occured in again in firefox, but interestingly, Google Chrome doesn't seem to have this problem. It looks like I can leave chrome alone for as long as I want and it will still work.
my solution currently has a website project and a class library project. I am attempting to access a session object from my class library but it is always returning null. In a settings class in my class library I store these values like so:
private static SessionProperty<WebUser> _currentUser = new SessionProperty<WebUser>("CurrentUser", delegate { return new WebUser(); }); public static WebUser CurrentUser { get { return _currentUser.Value; } set { _currentUser.Value = value; } }
I can access this just fine from any aspx page codebehind like so:
I test my asp.net website app in my win 2000 server in Administrator user mode, the session I start (Session("user_ses") = myclass) only lasts a few seconds. But if I do the same as a 'common' user the session lasts 20 minutes, which is the time I set in web.config file:
I am trying to pass a key value from one page to another, using VB.net and Visual Studio 2008 Professional. I am creating a session variable in one aspx page and trying to retrive the value in the second aspx page (Dircted to by a button with the postbackurl set) However, the session object is empty when I try to access it in the second page. If, however, i put a debug hold on the code which retrieves the variable, and examine the session object from the "locals" debug window, i see contents. When I then resume the application the code retrieves the value correctly. I am executing my code using the development server that comes with Visual Studio. Could it have something to do with that?
While working with mutliple tabs of same browser, session varibles/object gets over written with latest one.
Scenario in my application:
I have to create new employee on first tab(tab #1), and updating existing employee details on second tab(tab #2).I stored employee other details in Session["dtInfo"], use it on saving the record.Now Session["dtInfo"] having details of latest tab created, i.e. tab #2. I tried to save record on tab #1, facing the problem of session gets over written.I had to check some vaules on OnInit and OnInitComplete event. But I get here wrong values in session.
I noticed that when i am debugging my web application in Visual Studio 2005 using IIS, after about 10-15 minutes of inactivity, when I do something in the application such as a postback, I get an immediate error saying: "object reference not set to an instance" and my code breaks somewhere.Is my assumption correct that this is because my session has timed out? ( i do have a 15 minute default session time)my next question is, how do I display or set a way so that like many other pages, when the session has expired, a message will say: "This page must be refreshed" or "Your session has expired, click okay to refresh page" and start over again?
Ive created an object and placed it in the session, then in my .ashx handler I want to get that object from the session. The problem is that its always null !
heres how ive placed the object into the session from an aspx page
