I am confused about how to reference objects in session, how to update, and copy.
if I create
MyObject obj = new Object ();
then
Session["object"] = obj;
MyObject temp = (MyObject)Session["object"];
If i change something on temp, will the object in session be updated? do i need to follow changes with Session["object"] = temp?
I have a Session object
Session["MyListObjects"] = null;
When a user hits a button I want to creat a List<string> object and add to session object.
Let's say if user hits the button 10 times, I would get 10 List<string> objects and
add to Session["MyListObjects"] and
Finally I want to read all the List<string> objects from the session object.
I'm populating an object model with a linq query. The model looks like this:
MyModel{
DateTime AppointDate {get; set;}
int TotalAppoints {get; set;}
int AppointDuration {get; set;}
}
The linq-to-sql query looks like that:
public static GetAppointsFromDB(params){
var MyQuery = from....where...
select new MyModel{
AppointDate = ...,
TotalAppoints = ...,
AppointDuration =...};
return MyQuery as MyModel;}
In the master page, I'm looking to load the result of this query in the session like this:
if (Session["Appoints"] == null) {Session["Appoints"] = GetAppointsFromDB(...);}
When I run with the code, the session is always null. I added this line a second time, just right after, and the query runs again. When I'm looking to use the session at some other point in the code, it is null too there too. The query works because when I put a breakpoint on the return statement, I see the object properly filled.
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.
View 3 RepliesI have a problem by getting session which created for new site visit or session expired.
View 3 Replies----> I have datatable which is passing to another page in session variable.
----> Now on another page i take the session variable into datatable.
datatable ds_table = new datatable();
ds_table = (datatable)session["table_value"];
----> so problem, is that , when i filtering some rows from ds_table . that taking effect in the session variable. if some rows deleted from ds_table. then it is also deleted from session variable.
----> so, anyone tell me why is this going to happene?
I have many controls like dropdown, radiobuttonlist, etc on my page and I put all these controls inside the update panel so that the page doesn't look to be posting back when something is selected. Now the working on the page is very smooth. But the session object isn't getting refreshed even if I postback to the server and as a result even if the users are working on the page they are being sent to the login screen after 20 mins.
Is there anyway where I could put all the controls in update panel and still refresh the session after any postback(dropdown selection)
I open the browser login in the application. After login in the application I copy the URL and paste in the new browser.
How can i find out this is a new session ?
I have a object named post and I declare a new variable named newPost as type post object and then
var newPost = post
but when I Modify any properties of post object, that Modified Influences properties of newPost object.
I have a cached control object form a UserControl in asp.net cache. I like to access my control and make a copy of it to freely change it without having any affect on the base cached control.
View 2 RepliesIn the VS2005 environment, when I test my session to make sure the page redirects to the main page (itself) if the session is null, it works. There is no error.
The function I use for this is:
[code]....
However, when it is in the production environment in IIS 6.0, when the session has timed out, and I then do a postback by doing some slider control, I see the page reload but immediately thereafter, it throws a Server Error exception of : Object reference not set to an instance of object.
Looking at the stack trace, the event occured:
AJAXEnabledWebApplication1._Default.Slider1_TextChanged(Object sender, EventArgs e)
however, why is it that the Slider1_TextChanged event fired even even after during page_load, the page was told to do a response.direct ?? shouldn't the entire page have gone through a full-page refresh life cycle ? why did it continue on to attempt to raise the Slider1_TextChanged event?
I am getting object refernce error at line:if (Session["Tax"].ToString() == "9")
protected void Page_Load(object sender, EventArgs e)
{
if (Session["Tax"].ToString() == "9")
{
lblTax.Text = Session["Tax"].ToString();
}
else
{
lblTax.Text = "0";
}
}
Is anything wrong I have done?
I set a session object at one juncture in my code:
Session("my_name") = "Dave"
Later in my code I give the user a chance to update this object:
Session("my_name") = TextBox1.Text
I reload my page and display a little hello statement like this:
Label1.Text = "Hello" & CStr(Session("my_name"))
The result is: "Hello Dave" no matter what I change Session("my_name") too.
EDIT: Here is the a full code-behind I wrote up to demonstrated:
Public Class WebForm1
Inherits System.Web.UI.Page
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
Response.Cache.SetCacheability(HttpCacheability.NoCache)
Response.ExpiresAbsolute = DateTime.Now.AddMonths(-1)
If Page.IsPostBack = False Then
Session("my_name") = "Dave"
End If
Label1.Text = CStr(Session("my_name"))
End Sub
Protected Sub Button1_Click(ByVal sender As Object, ByVal e As EventArgs) Handles Button1.Click
Session("my_name") = TextBox1.Text
End Sub
I would like to serialize the properties of the HttpBrowserCapibilities object so that it may be returned via a web method call. Currently the object cannot be serialized:Cannot serialize member System.Web.Configuration.HttpCapabilitiesBase.Capabilities of type System.Collections.IDictionary, because it implements IDictionary. ...which is understandable. However, I would like to simply copy out the properties and their values to a hierarchy, i.e.
<HttpBrowserCapabilities>
<IsMobile>true</IsMobile>
</HttpBrowserCapabilities>
I'm starting to think I would need to use reflection to copy this object, but I haven't reached a conclusion. Does anyone have any suggestions to keep this simple?
I have this problem when trying to read a session in another asp.net page.
Object reference not set to an instance of an object.
If Session("cne").Equals("") Then Response.Redirect("Default.aspx")End If
I'm setting the session in the Default page with this code :
Session("cne") = cne.Text
I found some code on the web and it threw me off. Look at the code below. You will notice only when the Hits == 1, does the cache get added. After that, the cache object isn't updated. It begs the question, does the object when updated, update the cache as well automatically? The answer here would make me remove some code in some of my classes.
public static bool IsValid( ActionTypeEnum actionType )
{
HttpContext context = HttpContext.Current;
if( context.Request.Browser.Crawler ) return false;
string key = actionType.ToString() + context.Request.UserHostAddress;
var hit = (HitInfo)(context.Cache[key] ?? new HitInfo());
if( hit.Hits > (int)actionType ) return false;
else hit.Hits ++;
if( hit.Hits == 1 )
context.Cache.Add(key, hit, null, DateTime.Now.AddMinutes(DURATION),
System.Web.Caching.Cache.NoSlidingExpiration,
System.Web.Caching.CacheItemPriority.Normal, null);
return true;
}
I would only guess that I would need to add the lines after the if statement:
if( hit.Hits == 1 )
context.Cache.Add(key, hit, null, DateTime.Now.AddMinutes(10),
System.Web.Caching.Cache.NoSlidingExpiration,
System.Web.Caching.CacheItemPriority.Normal, null);
else if (hit.Hits > 1)
{context.Cache.Remove(key);
context.Cache.Add(key, hit, null, DateTime.Now.AddMinutes(10),
System.Web.Caching.Cache.NoSlidingExpiration,
System.Web.Caching.CacheItemPriority.Normal, null);
}
Found the code at the bottom of the page here: http://www.codeproject.com/KB/aspnet/10ASPNetPerformance.aspx?msg=2809164
How do you work-around the fact that sessions are dropped every time you deploy certain code files to an ASP.NET website? Sometimes we need to deploy a crucial fix in the middle of the day but don't want to boot off all our users for it.
View 3 RepliesI have a dropdown list with sessions: Summer, fall, spring, summer Interim.
And also have a gridview to display hours of those sessions. When chose session from dropdown it displays the data related to gridview.
Gridview has the 'Edit' option to edit hours for each sessions:
[Code]....
When I edit let say spring and update the field it redirects me to main page but everytime it selects the data from summer).
What I want is? If choose Fall from dropdown and make edit(in editpage.aspx?id=..) and update the data, then it should redirect to main page but choose the Fall from the dropdown (Not summer)
What namespace do I need in order to use the Session Object in my VB.Net code-behind?
View 7 Repliesmy main concern is using Session. I've always been under the impression that if you use the following statements (not that I would):
Session["newVar1"] = "a new session variable";
Session["newVar2"] = "a new session variable";
Session["newVar3"] = aLargeVariableThatHoldsLotsOfData;
You would be creating 3 new session cookies that hold the particular value. But I think my asp book is indicating that you would actually create 3 new variables in your session state object and ASP would only pass a unique Session ID (as a cookie?) in the response, and would get this ID upon the next request and associate that ID with your Session State Object (that IIS has stored in memory..?):
[code]....
That doesn't seem ideal for a website with lots of traffic. A server that is storing and maintaining thousands and thousands of instances of session state per website seems like way too much overload.
I'm trying to see what's going on on my own, but I'm having trouble.. I can't find my site's cookies anywhere on my machine (IE/windows xp). I've checked C:Documents and Settings icholasrCookies and C:Documents and Settings icholasrLocal SettingsTemporary Internet Files which, according to this yahoo answer, IE cookies are stored as well. I'm using ticket authentication in my app which stores a auth cookie on the client, so a cookie from my site has to be somewhere..
have been a great resource for me since i am new to MVC and trying to learn and figure out few things.My chain of thoughts still might be asp.net, so here is another question.I have a session object in my controller action which i use to populate my view , i need to clear the session object everytime i navigate out of the page (more like a session kill in page unload event). I really appreciate any ideas and inputs on how and where to clear the session object
View 8 RepliesI'm looking to build an ajax page; it's a reporting page. By default, load today's report. On the page there's a calendar control and when the user clicks on a date, reload the gridview with the corresponding data. Is it considered good practice to do the following:
1) on the first page load, query the data for the page
2) put the query result in the session object and display it in a gridview
3) if the user requests new data, get new data from the query with different parameters
4) put the result of the second query in the session object and display it
5) if the user then requests the data from the first query, get it from the session object
6) do the sorting and paging with the data held in the session.
Note: the data of each query will contain about 300-500 rows and about 15 columns. I'd like to do all this with ajax calls. What are some suggestions and pitfalls to avoid.
I have a DetailsView (DV) control, an ObjectDataSource (ODS) control, and a button on a page. I have 2 classes in the App_Code directory (Customer and CustomerDAO). The DAO class provides static methods for the ODS control and simply hack values in (ie...no real database selects/updates). The Customer class has 2 properties (Id and Name) and a default constructor. The page takes an ID on the querystring and determines if the DV control is in insert or edit mode. If in edit mode, it sets the SelectParameter on the ODS (id field), calls ODS.Select(), and then calls DV.DataBind(). The existing (although fake) customer is loaded and display properly when this happens. I then change the name of the Customer in the DV and click the Button to save the new data.
Everything seems to be wired up correctly as the UpdateMethod that is specified in the ODS control is called and succeeds (even in my real example with my database). The problem is that the BoundFields in the DV control have not been updated with the new values and therefore the existing values are updated in the database and my changes are lost. I have handled the OnUpdating event of the ODS and the values are still the old values. I have also handled the OnItemUpdating event of the DV control and the NewValues IOrderedDictionary still has the old values in it also. In looking at the MSDN article for the UpdateMethod, it states the following:
Parameter Merging
Parameters are added to the UpdateParameters collection from three sources:
From the data-bound control, at run time.
From the UpdateParameters element, declaratively.
From the Updating event handler, programmatically.
I am using the BoundField classes in my DV control so I would have assumed that the first bullet above would have handled the updating of values, but it doesn't appear to work with the way I am doing it. If I set the values explicitly in the OnUpdating event that is fired by the ODS control (the 3rd bullet) the right values are updated (again...even in my real database situation). It seems like my only issue is that the automatic binding that I expect from the DV control isn't working as I would expect it to. Here is the code that I have in my fake example:
[Code]....
On my web page, I've a shared object with initiate (open session) on the load event.
I would like to close this object when the page is close and invoke a close session method.
how do I use the event to do this?
I am facing a very strange issue. I get an error Object Reference Not set to instance of object on the server while the code runs fine on my dev machine. The strange part is the line number where the code is throwing error (as appears in the Stack trace)
DemoUser demoUser = new DemoUser();
if (!Request.QueryString.AllKeys.Contains("name"))
{
playerName = usr.NinjaName;
demoUser.Email = usr.UserEmail;
demoUser.UserPicture = usr.UserPicture;
}
else
{
playerName = Request.QueryString["name"];
demoUser.Email = String.Empty;
demoUser.UserPicture = "http://graph.facebook.com/1/picture";
}
demoUser.EntryDateTime = DateTime.Now;
demoUser.Name = playerName;
Session["DemoUser"] = demoUser;
imgPlayer.ImageUrl = demoUser.UserPicture; // This is throwing error.
If that line is throwing error then the demoUser object is getting lost when I assign it to Session. Is that right?
