What causes the 'Cannot unregister UpdatePanel' error? - asp.net

I've got a UserControl that contains an UpdatePanel. When I put that on a page, it throws the following error:
Cannot unregister UpdatePanel with ID
'ReviewContentUpdatePanel' since it
was not registered with the
ScriptManager. This might occur if the
UpdatePanel was removed from the
control tree and later added again,
which is not supported. Parameter
name: updatePanel
ReviewContentUpdatePanel is the name of the update panel & it's not being removed or added in code, it exists in the aspx page and isn't removed. Has anyone come across this before?

This error occurs when the Controls collection in which the UpdatePanel is resided is cleared using the Clear method, or when the specific UpdatePanel is removed using the Remove method.
A trigger for these methods could be the implementation of the CreateChildControls method for the control contains the UpdatePanel. Usually, you call Controls.Clear() in the top of this method, to start with a clean slate if this method is called repeatedly.

Are you moving controls about in code? If so take a look here and see if this solves your problem.

I had this happen once before. To fix it, I just deleted it and then re-created it and the problem went away.

I hope this helps someone else as it drove me nuts. After finding various tidbits of info here and there on here and elsewhere, I finally came up with the following fix. Note, I am not dynamically creating this update panel here or anywhere else and most info out there was related to creating this control dynamically, which I was not.
I was using an update panel inside a web user control used on a page inherited by a master page with the script manager. I don't know if this combo was what was causing it, but this is how I fixed it (inside the web user control where the update panel is utilized):
protected override void OnInit(EventArgs e)
{
ScriptManager sm = ScriptManager.GetCurrent(this.Page);
MethodInfo m = (
from methods in typeof(ScriptManager).GetMethods(
BindingFlags.NonPublic | BindingFlags.Instance
)
where methods.Name.Equals("System.Web.UI.IScriptManagerInternal.RegisterUpdatePanel")
select methods).First<MethodInfo>();
m.Invoke(sm, new object[] { updatePanel });
base.OnInit(e);
}

In your markup, make sure you've specified an ID for both UpdatePanels and for every runat="server" control in their parent hierarchies.

Have you tried including a ScriptManagerProxy in the user control?

Try to remove the scriptproxy of UserControl. In this case you only have a ScriptManager on your page.

This is a bit of a long shot, but I've had experiences with the AJAX extensions, specifically with the update panel, in which errors thrown by child controls were manifesting themselves as a different error thrown by the update panel. I did see a reference to this specific error being thrown due to an error in a child control:
http://msmvps.com/blogs/shareblog/archive/2009/03/11/cannot-unregister-updatepanel-with-id-since-it-was-not-registered-with-the-scriptmanager-and-moss.aspx
Not sure if this is the case for you or not, but I've spent many hours chasing down the wrong errors because of this.

Related

Failed to load viewstate. The control tree into which viewstate is being loaded

I am receiving the following error message after an HTTP POST on an ASP.NET form hosted inside a UserControl:
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. For example, when adding controls dynamically, the controls added during a post-back must match the type and position of the controls added during the initial request.
Here's additional info:
I'm running .NET 4.5 RC
It's an Umbraco 4.7-based website
On my local dev machine the form works perfectly
This error only occurs on the staging server which has .NET 4.5 (only), MSSQL 2012 Express, IIS 7.5, Windows 7 (I know, it's not a real server yet, one day maybe...)
The server is not part of a web farm (or garden, tho that should be irrevelant)
The user control does render controls dynamically
I have applied all the latest service packs.
I have run out of ideas now! I have even restarted it and also performed a richual over the server involving a song and a special dance to no avail.
What is important when you are adding controls dynamically is on which event you are adding them.
If you added controls on events that occur after load, they will be part of the viewstate you send to the client.
You will have to add those controls again before LoadViewState is called.
If you run into cases where the decision of which controls to add is itself stored in the ViewState or the value of a control, then remember even before the ViewState is loaded, this data is available in Request.Params
Refer the asp.net page life cycle
I just added EnableViewState="false" to my page placeholder and its gone. Hope it works for u as well.
This Error Mainly Occurs during View state Change: From One Template To other Template like in case of Item Template, Edit Item Template, in Controls like Form View, List Views, Detail View, Grid View in ASP .net (all frameworks);
While Changing from control states say Item Template ---> Edit Template
the followings were going to alter
1) Controls will change (its ID & states)
2) Its Positions will change.
While Transformation of view if any post back occurs you will get Error as
Failed to load viewstate. The control tree into which viewstate is
being loaded....
if you are using separate control for data-binding like (button,link_button_Image_button events) you will get this error reported !
To avoid this error >>> Once state changes from one template to other within method you call data source binding ( Don't call during click or any post backing events ).
OK, so the answer is literally: "Set up a new server with all the same software as the last one and try again" and it works now.
I add "name" attribute with the same value as id, then this problem is gone.
<input type="button" id="extractBomInfoBtn" name="extractBomInfoBtn" value="Extract" class="button textonly" />
I had the same issue. This issue was at client end but it didn't occur in my local system.
After hours of googling, i had written EnableViewState="false" to my table tag in aspx page which has all the dynamic controls and then i removed all the viewstate variables and instead i created some hidden textboxes in the aspx page and accepted DB values into them in code behind and used them throughout my code. It then solved my problem.
But still, i couldn't figure out what was exactly the problem.
In my case I was manipulating the .Text property of a asp:Literal on page load which was causing the issue. In all other cases this never caused me a viewstate error but in this particular case I was changing the .Text value to an html element.
The following caused the error:
<asp:Literal ID="SvgIcon" runat="server" />
SvgIcon.Text = "<svg version=\"1.1\" id=\"Layer_1\" bla bla />"
I was able to resolve the error by adding EnableViewState="false" explicitly to the control:
<asp:Literal ID="SvgIcon" runat="server" EnableViewState="false" />
Check if you have the binding method of the control directly in your page load event. This can cause this problem.
You can add new PlaceHolder per UserControls
OR
You can set enableviewstate=false on the control , if you dont need viewstate
In my case I had a grid view with (OnPageIndexChanging) event
and when I click on a page nothing will happen until I click it twice!
I was refreshing the data source before setting new page index.
This is what I was doing wrong
grd.DataSource = data;
grd.DataBind();
grd.PageIndex = e.NewPageIndex;
This is the right way
grd.PageIndex = e.NewPageIndex;
grd.DataSource = data;
grd.DataBind();
This can happen if you override SaveViewState in your control but don't override LoadViewState.
So I actually ended up discovering that the list of entities I was binding to was not in the same order as the controls in ViewState! I'm still working thru a cleaner solution, but my code is working with ViewStateEnabled = true by having the method which reconstructs my dynamic controls (called from Page_Load) do it differently if !IsPostBack.
Ultimately, I will probably need to fix my sorting algorithm for my nested dynamic controls, but suffice it to say: if you are using the same pattern as I am, of using a List to generate/bind to dynamic controls, and that order is fluid or changing, try comparing Request.Params to find the keys that are relevant to your control hierarchy, and see if they match the order of your List. That solved my issue. Kudos to #nunespascal!
In short, I am dynamically generating all but one tab in an AjaxToolkit tab control, and then populating that with a couple layers deep of placeholders and regular controls (textboxes, dropdownlists, etc), so that's why it's complicated to get the order of everything correct.
Although this is very old question, I had visited this as I got the similar issue. But my issue was generated just because I have added a javascript code in Master page in head tag. That javascript code is reading a value of Session["KeyName"] ,
Code is like below -
$(document).ready(function () {
var allowOpenInNewTab = false;
allowOpenInNewTab = '<%# Convert.ToString(Session["AllowOpenInNewTab"]).ToLower() %>' == 'true';
if (!allowOpenInNewTab && window.sessionStorage.tabId != '1') {
alert("This page is not allowed to be open in another tab, sorry we can not load the page!!");
}
});
When I remove above code then everything was running smoothly but if I keep adding this part of code, it was giving this error of
Failed to load viewstate. The control tree into which viewstate is being loaded must match the control tree that was used to save viewstate...
Finally I found the solution like if I move my javascript code from head to just before the end of the body tag.
So solution that worked for me was moving javascript code (which is reading Session value from Server tags) to just before end of body tag.

ASP.NET 3.5 validation groups not working

I wish I could paste in my markup, but it's too complex and contains a lot of references to the client's company name. I am hoping someone with vast experience might be able to point me in the right direction.
We have a master page with a ValidationSummary that is not part of a validation group. On our content page, we have another ValidationSummary that is assigned to a validation group called ValReject. On the content page is also a CustomValidator that uses ClientValidationFunction and a button, both of which are also assigned to ValReject.
When I click the button, the client function executes once, but the error reports to both validation summaries, the one on the content page and the on on the master page. I even added a third validation summary and set its group to something like "asdf", but it gets reported to, as well, meaning all three validation summaries are showing the same error on the page.
I then created a separate ASP.NET test project, pasted all the code in, and ran it and it validates like it should.
I then played around with AutoEventWireup on the content page. When I set it to false, validation works, but the page load event doesn't fire. What's up with that?
I know you probably need code samples, but, like I said, I just can't do that without going through a huge headache (trust me, the master and content page markup is huge.
The question here is: Does anyone have an idea of what could cause a single validator to report to ALL validation summaries on the page even though only one of them shares the same validation group as the validator and button?
edit: When I pasted the markup into my test app, I did have to remove some tags to get it to work since the test app doesn't have references to some assemblies used by the real master page. Some things I removed are:
<%# Register Assembly="RadMenu.Net2" Namespace="Telerik.WebControls" TagPrefix="radM" %>
<radM:RadMenu ID="RadMenu1" runat="server" DataSourceID="smdsMenu" Skin="CssGrey" ClickToOpen="True" EnableViewState="False" CausesValidation="false" />
So the fact that it works on my test app leads me to the conclusion that we're doing something on our production app that I am not doing in my test app. Yes, I know this is vague, but perhaps a light bulb will go off in someone's head.
Man, after hours and hours of spinning my wheels, I finally figured it out. We use this extension method to disable double clicks of buttons:
public static void DisableDoubleClick(this Button Control)
{
System.Text.StringBuilder sb = new System.Text.StringBuilder();
sb.Append("if (typeof(Page_ClientValidate) == 'function') { ");
sb.Append("if (Page_ClientValidate() == false) { return false; }} ");
sb.Append("this.disabled = true;");
sb.Append(Control.Page.ClientScript.GetPostBackEventReference(Control, ""));
sb.Append(";");
Control.Attributes.Add("onclick", sb.ToString());
}
This is what was messing up the validation as it was invoking global validation. I fixed this by making the following change:
sb.Append(string.Format("if (Page_ClientValidate({0}) == false) {{ return false; }}}} ",
Control.ValidationGroup == string.Empty ? string.Empty : string.Format("\"{0}\"", Control.ValidationGroup)));
What clued me in was when I set AutoEventWireup to false to see what would happen. This kept the page load event from firing which is where the above extension method was being called. What a needle in the haystack, this problem.
I don't blame anyone for not answering due to lack of details, but I will keep this up in case anyone else can use it.
edit: Thanks to slfan and gbs. I had just figured out the issue and was coming back here to post my answer when I see that you two were essentially tackling my issue from both sides of the problem. The page load event is where the binding was occurring and the extension method being called was messing up the Page_ClientValidate function. Since you both are technically right and I can't award both of you the answer, I hope no one gets upset if I mark my own as the answer here. You two are definitely good at analyzing such issues with minimal details and no code samples. Props.
The AutoEventWireup causes ASP.NET to call the Page_Load event automatically without having to register to an event. An alternative could be to override the OnLoad method. Your page seems to work properly when Page_Load is not called. What do you do inside this method? Some strange data bindings? What if you uncomment this code, will it work then? Like this you could narrow your problem down to the real problem which you are not showing in your question.
Two things I would look for:
1: Any external validation using Page_ClientValidate being done in javascript
2: Any explicit call to Page.Validate() in code-behind

Failed to load viewstate. The control tree into which viewstate is being loaded must match the control tree that was used to save viewstate

I'm currently working on a dynamic core for several webprojects. It has a core that uses a treeview and a menu. And then for each specific projekt it loads several different wuc into a maincontent. Some business projects use business related wucs while others uses different ones. So the span of wuc's is really big.
Now to my problem, whenever a user press a menuitem or a treeitem it loads a wuc to the maincontent linked to that object.
But I'm having some viewstate errors and i've been looking around for 2 days now and none of the solutions explained are working for my projekt.
All my wuc has to have viewstate enabled.
Cycle is ->
Page(Control A) does postback with variable to change control to ControlB in wucPanel(UpdatePanel).
OnLoad LoadRequested Wuc.
Current code is
protected void Load_Page(object sender, EventArgs e)
{
//Code to decide which wuc to load.
UserControl wucc = (UserControl)Page.LoadControl(sFilePath);
ParentControl.ContentTemplateContainer.Controls.Add(wucc);
}
I've tried several fixes like adding diffrent ids to the wuc, but this either disabels the internal functions of control like handlers etc or generates the same viewstate error.
One solution i found was to load ControlA and then just removing it and then load ControlB. But this disabled the scripts for my 3rd party controller (Telerik).
I've also read about having diffrent PlaceHolders for each typof but since i expect havign up to 50 diffrent Controls I don't feel this is gonna help me.
And moving from Page_Load -> Page_Init generated the same error.
Error:
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. For example, when adding controls dynamically, the controls added during a post-back must match the type and position of the controls added during the initial request.
In your case Anders, you still need to add the old control to your page in the init method along with the new control that you now want to add. Keep a reference to this old control that you have just added in a class level variable. So something like
Control _oldControl = null;
protected void Init_Page(object sender, EventArgs e)
{
//Code to decide which wuc to load.
UserControl wucc = (UserControl)Page.LoadControl(sFilePath);
ParentControl.ContentTemplateContainer.Controls.Add(wucc);
_oldControl = wucc as Control;
//Now add the new control here.
}
//override the LoadViewState method and remove the control from the control's collection once you page's viewstate has been loaded
protected override void LoadViewState(object savedState)
{
base.LoadViewState(savedState);
ParentControl.ContentTemplateContainer.Controls.Remove(_oldControl);
}
Hope this helps. If it did, please check the checkbox next to this answer to accept it and vote it up if you like :)
In order to avoid ViewState related errors please make absolutely sure that in Page_Init you create the same control tree that was created the previous time ViewState was saved i.e. the previous postback. Simple page life cycle:
Page Init - create the control tree
- View State is loaded and applied here
Page Load - already loaded view state, you can do modifications to the control tree here
- Save View State
Page PreRender
For what it’s worth I recently had the same problem.
My scenario was as follows.
A fixed panel of filters (dropdown lists and textboxes) which built a search SQL string. On submission of the search consequent results were displayed in an editable gridview beneath.
On editing the gridview I cold effectively change the state of a database record thus removing it from the gridview under the filters previously chosen. In some cases this resulted in no results being returned thus causing me to hide the gridview.
I then found that if I used the new state of the record in the filter and resubmitted the search that error sometimes occurred.
The problem I eventually found had nothing to do with enabled viewstates etc but simply that the empty gridview, though no longer visible (changed programmatically), had not been rebound to a null datasource.
This appeared to cause the conflict and the error.
So it appears as though in my case the viewstate issue arose from a non-visible gridview that contained non-refreshed data.

What's the difference in behavior between adding a control to an ASPX page directly, loading a control programmatically & adding to a placeholder?

Is there a difference in behavior between adding a control to the ASPX page directly and loading a control programmatically and adding to a placeholder?
The control inherits from System.Web.UI.WebControls.DataBoundControl.
The reason I ask is that I have a control that works when I add it to the ASPX page like so:
...
<blah:GoogleMap ID="GoogleMap1" runat="server" Width="640px" Height="600px" ... DataSourceID="_odsMarkers" DataAddressField="Address" DataTextField="Description">
</blah:GoogleMap>
...
But not when I use the following in a codebehind page:
GoogleMap map = (GoogleMap)this.LoadControl(typeof(GoogleMap), new object[] { });
//... set properties
this.placeholder1.Controls.Add(map); //add to placeholder
Anyone have any ideas why this might be the case?
The control tree ends up the same if you define in markup or add programmatically. However there is plenty of room for the control implementor to screw up along the way.
You can go look how ASP.NET compiles the aspx:
C:\Windows\Microsoft.NET\Framework\v2.0.50727\Temporary ASP.NET Files
The timing when the control is added to the page might be an issue. The usual pattern is add the control in an overload of the CreateChildControls method. If the control needs to resolve viewstate you need to make sure this is called during init, e.g. by calling EnsureChildControls.
Adding to ninja's debbugging hint. Does it make any difference if you add a label the same way. Does it show up?
Is this a user control or server control?
If it's a user control they should be loaded by their path and not their type:
GoogleMap map = (GoogleMap)this.LoadControl("~/Controls/GoogleMap.ascx");
If it's server control then you can just new up an instance:
GoogleMap map = new GoogleMap();
after you have the instance and add it to the control tree (by inserting it into the PlaceHolder) it should perform the same as when it would have been declared in the markup.
If you are setting properties outside of the LoadControl call, why are you making that new empty object array instead of just using the overload that has one parameter?
Also, if you attach a debugger to it and step through, do you notice anything weird about the control before you do your Controls.Add() call? Is there an exception being thrown? if so, which one? if not, what does the markup in the browser look like for where the placeholder is?
"Works" is kind of ambiguous, but if you mean, event handlers are never executed, you need to load it in the page onload event.
If the control requires the use of viewstate you must ensure that it is added to the page BEFORE the Page_Load event, otherwise viewstate will not be populated and most likely events and other items will not function properly.
One important difference is that if you create a control dynamically, you will not get, by default, any values from skins set. You must manually call control.ApplyStyleSheetSkin(page): http://msdn.microsoft.com/en-us/library/system.web.ui.control.applystylesheetskin.aspx

Creating a UserControl Programmatically within a repeater?

I have a repeater that is bound to some data.
I bind to the ItemDataBound event, and I am attempting to programmatically create a UserControl:
In a nutshell:
void rptrTaskList_ItemDataBound(object sender, RepeaterItemEventArgs e)
{
CCTask task = (CCTask)e.Item.DataItem;
if (task is ExecTask)
{
ExecTaskControl foo = new ExecTaskControl();
e.Item.Controls.Add(foo);
}
}
The problem is that while the binding works, the user control is not rendered to the main page.
Eh, figured out one way to do it:
ExecTaskControl foo = (ExecTaskControl)LoadControl("tasks\\ExecTaskControl.ascx");
It seems silly to have a file depedancy like that, but maybe thats how UserControls must be done.
You could consider inverting the problem. That is add the control to the repeaters definition and the remove it if it is not needed. Not knowing the details of your app this might be a tremendous waste of time but it might just work out in the end.
If you are going to do it from a place where you don't have an instance of a page then you need to go one step further (e.g. from a webservice to return html or from a task rendering emails)
var myPage = new System.Web.UI.Page();
var myControl = (Controls.MemberRating)myPage.LoadControl("~/Controls/MemberRating.ascx");
I found this technique on Scott Guithrie's site so I assume it's the legit way to do it in .NET
I think that #Craig is on the right track depending on the details of the problem you are solving. Add it to the repeater and remove it or set Visible="false" to hide it where needed. Viewstate gets tricky with dynamically created controls/user controls, so google that or check here if you must add dynamically. The article referenced also shows an alternative way to load dynamically:
Control ctrl=this.LoadControl(Request.ApplicationPath +"/Controls/" +ControlName);

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