How To See If Viewstate Changed When Postback

May 12, 2010

well what i want to find out is how can i figure out if some change occurd in page when postback , i mean when the first state of the page hahe any changes after postback . I thought maybe somehow to compare viewstaes but i can not find out how can i do that.

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form id="form1" runat="server" enableviewstate="true">
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[code]...

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Viewing The Size Of The Viewstate On Any Given Postback?

May 4, 2010

Is there a reliable method for viewing the size of the viewstate on any given postback?

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State Management :: ViewState Value Set After 2nd Postback?

May 3, 2010

I 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]....

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Is it necessary to reload the viewstate of usercontrols during postback? I want to know in which case viewstate is set by default.

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Jun 4, 2010

I've got a weird problem with a NullReferenceException on a high traffic website my company hosts. The exceptions are logged with full stack-traces but I am unable to reproduce it.The exception occurs a couple of times a day, for different users, and it's a NullReferenceException thrown in the code block below:

protected void Page_Load(object sender, EventArgs e)
{
...

if (!Page.IsPostBack)
{
...
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...
}
}

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StaticStringProperty is defined as:

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EDIT.As requested, the full stack-trace for the error is as follows. Line 54 is the line I've highlighted above.

at MyCompany.MyApplication.Appliance.Page_Load(Object sender, EventArgs e) in C:Documents and SettingsshellamaMy DocumentsMyApplicationAppliance.aspx.cs:line 54
at System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o, Object t, EventArgs e)[code]....

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May 12, 2010

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Public Property DataTable() As Data.DataTable
Get
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Else
Return Nothing
End If
End Get
Set(ByVal value As Data.DataTable)
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End Set
End Property

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I'm getting some strange behaviour with viewstate being lost on postback for a .net application using Sitecore. I'm assuming it might be some config variable somewhere but I'm new to Sitecore and don't really know where to start looking.

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I've made a mini test if that might help. It's two usercontrols on one page, both with a repeater. When updating the viewstate gets lost so even if I'm binding the updated repeater again the data for the other one will be lost.

Usercontrol 1:

<asp:Repeater runat="server" ID="Repeater1" OnItemDataBound="Repeater1_ItemBind">
<ItemTemplate>
<li>
<asp:Literal runat="server" ID="Literal1"></asp:Literal>[code]....

what might be going on? Let me know if I need to provide any more information. The most annoying thing is that it was working last week but I have no idea what has changed!

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Web Forms :: Increase ViewState Size And PostBack

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The values are stored in viewstate fr the postback... Does everysubsequent post back increase the viewstate size?

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Custom Server Controls :: Visible State Of The Div Is Changed In Client Code W/o A Postback?

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In ASP .NET 2.0, I've created a user control which is meant to work as a dropdown or popup by using an <input type="button" id="btnTogglePopup" runat="server" style="display:inline"... /> and <div id="divPopup" runat="server" style="display:none" ... /> the rest of the controls are contained inside this div, and they do mantain their values between posts, etc. This button 'runs at server' but it's not intended to post back or submit.It just toggles the popup (div) visible/hidden using Javascript client code by setting the div's style display property to "none" or "block" The problem I'm having is that when a page containing this control posts back, the state visible/hidden of the div is not maintained. If the user had the popup open, after the postback, it will display closed.I've read a bunch by now about ViewState & ControlState, and have the save and load contol state methods working, but when I step thru them they load old values (setting the popup to hidden all the time),and the popup doesn't work! I've come to think that b/c when the button is clicked,the visible state of the div is changed in client code w/o a postback, maybe I have to maintain this state info in a hidden fiel or something like that?At the same time I don't want to have a hidden field if it's unnecessary,and I may just doing something wrong.

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Forms Data Controls :: Gridview Attribute Changed By Javascript Is Lost On Postback

Sep 10, 2010

I have a gridview control that extends the default gridview. I have added an attribute called "hiddenSelectedValues" to to the gridview during the "PreRender" event and I have a private variable that points to the value of that attribute.

I have some javascript code that modifies the value of this attribute based on the user checking or unchecking checkboxes in the grid. I have confirmed that the javascript is indeed modifying the value of the "hiddenSelectedValues" attribute by using Firebug to see the change as it happens.

However, once a postback occurs, the grid looses the updated value of this attribute and I am unable to reference get the updated value on the server side.

How do I keep the value of an attribute changed by javascript on postback?

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I have a bit of javascript that presents a modal to the user with the rest of the page "grayed out." Pretty common these days. The modal allows you to specify a URL which then uses AJAX to serve and display. What I need is that when the control posts back, it posts back to the parent page, not the modal page. To attempt this, I used javascript to alter the target of the modal page's form element to the parent page's URL. When I try this I get the following error:

Validation of viewstate MAC failed. If this application is hosted by a Web Farm or cluster, ensure that <machineKey> configuration specifies the same validationKey and validation algorithm. AutoGenerate cannot be used in a cluster.

This is done locally and as of now, the app will never be on a cluster. I think this has to do with the validation process and .NET doesn't like that I've changed the target. Anyone know a way around this? I really need this to work how I described.

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Oct 23, 2010

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Apr 19, 2010

I have "n" <tables></tables> on my page and each <table> has One(1) <asp:CheckBox.. Enable ='true"/> and "x" <asp:TextBox Enabled="false"..>. Each Table looks as follows

[Code]....

When I click checkbox, it calls javascript function and enables textboxes (I have added onclick attribute to checkbox). Page also has <asp:Button ...Text="Submit"/> whcih actually grabs the data from the textboxes on the page and send it to the databse. Here is the Onclick event of the <asp"button../>

[Code]....

If the exception is thrown , textBoxes are not reset but on postback textboxes appear as disabled (values are not reset)

So here is what happening on postback when exception is thrown

1) Values are not reset (that is what want)

2) Texboxes appear as Disabled (that is what I don't want on exception, REMEMBER I enable textBoxes using client side script)

How can I keep the textboxes enabled = "true"

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Sep 8, 2010

I've build a class like this:

[code]....

The values of this class are set at postback by clicking a radiobutton list. Problem however is I don't know how to save this values across multiple postbacks. I thought of using viewstate but I'm not quite sure how to do it with this class.

Maybe I'm missing some important thing here.

Hope someone can point me in the right direction.

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