When I try to save an object reference in a view state it tries to save the object content using serialisation. to save the object reference only to apply to this object instance after postback?
View 5 RepliesI have a url like this:
http://www.somepage.com/main.aspx. In this page, when I click on a link it takes me to a page
http://www.somepage.com/cental.aspx?cid=200. So in the cental.aspx.cs page I did the following in the page load:
if(request.querystring["comp"].tostring() != null)
{
//do some thing [code].....
So I got an error like: object reference not set to an instance of reference.My problem is, I am using the same page. So when I go from some page, I will have "comp". but other times not. So when there is no "comp", how do I handle it in request.querystring?
I have created a custom control that extends the class ImageButton, the thing is that I now also want to save this control to a viewstate.
View 4 Replieshow save int array in viewstate?
View 4 Replieshow to save the CheckBoxList values into the viewstate
for e.g.i've a CheckBoxList with 4 ListItems,
if I check 1 & 3 items, then I close the page
if I re-open the page, items 1 & 3 must be checked.
We have an applicaiton that was converted to the new framework using the wizard in Visual Studio 2008. When we install the applicaiton in production and change the iis settings to use the 2.0 framework we start to see these errors in the event viewer on the web servers. We are using SQL Server Session State and have 3 web servers in a load balancer. Object reference not set to an instance of an object.</Message><StackTrace> at System.Web.SessionState.SessionStateModule.PollLockedSessionCallback...
View 1 RepliesI have a problem.This particular code when used on local machine is working fine, but when it is used on serverit gives an error like " Object reference not set to an instance of an object.Exception Details: System.NullReferenceException: Object reference not set to an instance of an object._isRefresh = _refreshState == (bool) Session["__ISREFRESH"]; "
View 1 RepliesI have overridden the following methods:
LoadPageStateFromPersistenceMedium()
SavePageStateToPersistenceMedium(object viewState)
in a class that my page derives from, so that the viewstate can be stored in DB.
Now, on page_load of my page, I am checking what control caused a postback & based on that I am forcing execution of 2 button click events in a row (by overloading those click events & calling them explicitely), but the behaviour I want is as if the execution of those 2 button click events went through the regular page life cycle.
Here is the sequence of events that happen in typical page life cycle & notice I want to alter behaviour at step 4 (on load):
1) Initialization
2) LoadViewStateData (here the viewstate is loaded from my database using the overridden LoadPageStateFromPersistenceMedium)
3) LoadPostBackData
4) Load
Here, I would like to force execution of 2 button_click events based on whether a particular control posted back.
4.1) imgBtnPrev5_Click()
4.2) imgBtnPrev4_Click()
Now, when the imgBtnPrev5_Click() is executed, the viewstate is already loaded, so we are fine. But after execution of imgBtnPrev5_Click(), I would like to update the viewstate object in memory & then call the overridden SavePageStateToPersistenceMedium (by passing that updated viewstate object as its parameter) and then before execution of imgBtnPrev4_Click(), I would like to call the overridden LoadPageStateFromPersistenceMedium.
5) RaisePostBackEvent
6) SaveViewState
7) Render
My question is, how do I update the "viewstate" object of the page - that is passed to SavePageStateToPersistenceMedium with the changes made to the controls in imgBtnPrev5_Click()?
i am facing the following problem while saving the viewstate on the server side using the savepagestatetopersistencemedium, but this is not working for the pages which contains update panel.
View 2 RepliesI 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?
View 1 RepliesThe a way to save an object in session with expiry time , such as when you're saving object in cache.
View 12 RepliesNow here is the weird thing. First i am running it locally on the built in vs2008 web server.I load my control in fine, do a postback from a linkbutton, locally on my machine it all works fine, no issue.However when it goes onto my host, it falls over with the message:
Failed to load viewstate. The control tree into which viewstate is being loaded must match the control tree that was used to save viewstate during the previous request.Now i also load controls dynamically and use postbacks and things in the admin area of the site...and that works fine, however my front end just keeps failing? See the code behing below:
[Code]....
I have problem getting values from viewstate in GetTopThemes.
<asp:ObjectDataSource
ID="sourceGetTopThemes"
runat="server"
TypeName="DBConnection"
SelectMethod="GetTopThemes"
EnableViewState="true"></asp:ObjectDataSource>
[Code]....
}
[Code]....
when the page is not Posted back, I saved all values in the viewstate.
I have been getting this error a lot lately with some of my users, and I had a couple of concerns with view state and I have read so many articles but I am still lost..
1. I use masterpage on all the pages and I need viewstate for some of the pages but..
There is a page where a user will fill out the information and then submit this data to a cgi server, and it is where I get most of the Client Disconnected errors, what would happen if I disable viewstate when they click on that button?
Now when a user browses from one page to another, does the view state from the previous page get deleted? If not how would I delete it?
Does the master page have its own viewstate? Would I be able to make sure none of items on my master page are using the viewstate?
I want to know that when we create custom controls, then is there State Management through ViewState done automatically or we have to handle it explicitely ?Since i have created Custom Controls that is behaving as if it is not maintaining its state on PostBack.
View 9 RepliesI start with a blank ASP.NET page where I disable ViewState for the whole page with EnableViewState=False and even ViewStateMode=Disabled.keep adding various controls to the page -- Label, Table, Calendar, TextBox, DropDownList.Everything looks good, i.e. my __VIEWSTATE tag fluctuates between 24 and 28 characters.As soon as I add a single RadioButton (or CheckBox), the __VIEWSTATE shoots up to 130 characters. And it keeps growing by over 100 characters every time I add another RadioButton.
View 19 RepliesI have a code like this in the Me.LoadComplete event.
[Code]....
Now I would like to set this viewstate("data") = nothing on a certain button click in a user control (.ascx) in this page but it doesnt clear the viewstate. What am I doing wrong? In the onClick even of the button in the .ascx I write Me.viewstate("data") = Nothing
I want to use textbox value after I visit from current to other page then again to current page using viewstate but value should be the one when I was current page last time.
View 3 RepliesI am creating a simple string of values that get added to a label after a post back. I am setting the values thorugh ViewState. However, my appended values do not get updated until AFTER the 2nd postback. Example:
On Page_Load the label displays a "0";
If I enter a "1" in the text box and click the button the label still displays a "0";
If I click the button again (the 2nd postback) then my label correctly displays "0,1"; This works for whatever value I enter after. i.e. "0,1,35,hello world", etc.
What I am I missing? Code Below.
.ascx - I left out inherits and codebehind
[Code]....
have some viewstate value in my opener window ,when i close the popup i want to set new value in the opener viewstate.
View 3 RepliesI am developing a a web application of a general store where the operator has to enter the things what customer has purchased. Like daily usage item,or anything. So I have form in which I first ask how much item u wannt to register...(if he has 20-30 number of items then operator will enter 20-30 then in gridview 20-30 item are opened. With bind dropdownbox containing name of item ,then textboxs containing mrp, value, stock avail of that item. Here is the link for demo. [URL]. Problem is suppose the operator enter the value above 20, then viewstate size id about 1.50Mb that's too heavy.
[Code]....
Here is .cs code
[Code]....
I stored a list<mytype> object in a viewstate. Type of list<mytype> comes from a public structure which is defined at page.
When I try to convert viewstate to a list<mytype> object it cause error.
Public struct mytype
{....}
Page_load()
{ list<mytype> obj = new list<mytype>();
viewstate["mystate"]=obj
}
My_function(){
list<mytype> tempobj = new list<mytype>();
tempobj = (list<mytype>)viewstate["mystate"];// this line cause error !
}
I want to store List<Class> object to ViewState, when i try to do this than its giving me error to make class serialize,but my class is partial class so didn't get serialize keyword on class how can i store List object to viewstate.
View 4 Repliesi want to store IQueryable value to ViewState. my code is as below:
Private
Property _Query()
As IQueryable
Get
Return
CType(ViewState("_Query"), IQueryable)
End
Get
Set(ByVal value
As IQueryable)
ViewState("_Query") = value
End
Set
but when i run my page i get following error:
Type 'System.Data.Linq.DataQuery`1[[DynamicQueries.VW_EmployeeProfile_Filter, DynamicQueries, ersion=1.0.0.0, Culture=neutral, PublicKeyToken=null]]' in Assembly 'System.Data.Linq, Version=3.5.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' is not marked as serializable
what should i do to get rid of this error. previously i was doing like this:
Private Shared _Query As IQueryable
but problem is that in Multi users environament, Shared variable is making problem, that is why i want to store it in ViewState.
As you know viewstate can recognize as a vulnarable item if we do not encrype it I know how to encrype the viewstate that I define in a web page but my problem start from here I downloaded a software which help you to exract the unencrypted viewstate of every website the link of that software is as follow:
[URL]
but when I make even empty page without viewstate ,this program can extract the viewstae of my page but if check some website like google ,yahoo,amazoon