I've registered two namespaces in Web.config like this:
<add tagPrefix="a" assembly="WebApplication1" namespace="WebFormsApplication1.Controls1" />
<add tagPrefix="a" assembly="WebApplication1" namespace="WebFormsApplication1.Controls2" />
I'm using them like this in an .aspx page:
<a:WebCustomControl1 ID="Control1" runat="server"></a:WebCustomControl1>
<a:WebCustomControl2 ID="Control2" runat="server"></a:WebCustomControl2>
Here's the (broken) .designer.cs file VS generates for that page (notice that it uses Controls2 namespace for both controls, although Control1 lays in Controls1 namespace):
protected global::WebFormsApplication1.Controls2.WebCustomControl1 Control1;
protected global::WebFormsApplication1.Controls2.WebCustomControl2 Control2;
It looks like the second <add in Web.config is overwriting the first one.
I want it to append rather than overwrite, is it possible?
I guess there are other alternatives as well:
Put everything in a single namespace
Use an unique tagPrefix for each namespace
But they are not cool since we have about a hujilion of controls here.
Notice that if register the namespaces in aspx itself, it'll work fine:
<%# Register TagPrefix="a" Namespace="WebFormsApplication1.Controls2" Assembly="WebFormsApplication1" %>
<%# Register TagPrefix="a" Namespace="WebFormsApplication1.Controls" Assembly="WebFormsApplication1" %>
So it looks like some bug in Web.config parsing.
(I'm on VS 2017, but they told me it happened since VS 2010 at least).
In cases where I needed this in the past, I had deleted the designer files and Manually declared all the controls in the code behind.
There may also be a way (but I don't recall exactly how) to tell the Designer to not generate those specific controls in the designer file. Then you manually add them in the code behind.
The Usercontrol I am creating is made up of 3 files as expected (ascx, ascx.cs, and ascx.designer.cs)
My Problem :
Controls created in the aspx page ( asp:Button runat="server" id="mybutton" />) are not being initialized properly, such that attaching to the 'Load' event, and trying to use button, results in a null object exception
I suspect this is a Visual Studio problem, either weird bug or unusal setting, but it wouldn't surprise me if I'm doing something silly.
My attempted work-a-arounds
I've copied another working User control from a different project into this project in visual studio and it too does not work (controls defined in ascx page are null in load event in code behind page, though they work fine where I copied them from)
I'm using the 'CreateChildControls()' method, as I've done in some other composite controls, but then everything is still null in the load and init events
I've created a seperate solution and project file, and added all the files and references, but still, this does not help the situation.
It appears to me that the 'page life cycle' (control life cycle?) is not initializing the controls properly for some reason, but cant see why, please someone help.
Posting my code as request :
PersonalDetails.aspx
<cwpEditControl:PersonalDetails runat="server" id="edtPersonalDetails" />
PersonalDetails.ascx
<%# Control Language="C#" CodeBehind="PersonalDetails.ascx.cs" Inherits="company.web.CustomerWebPortal.controls.edit.PersonalDetails" %>
<asp:Button runat="server" ID="myTestButton" />
PersonalDetails.ascx.cs
public PersonalDetails()
{
this.Load += new EventHandler(PersonalDetails_Load);
}
void PersonalDetails_Load(object sender, EventArgs e)
{
this.myTestButton.Text = "Submit"; //this line creates an exception!
}
PersonalDetails.ascx.designer.cs
protected global::System.Web.UI.WebControls.Button myTestButton;
I have fixed my problem by adding to the web.config file, basically 'registering' my custom control across the entire web application I am creating :
<pages>
<controls>
<add tagPrefix="scottgu" src="~/Controls/Header.ascx" tagName="header"/>
<add tagPrefix="scottgu" src="~/Controls/Footer.ascx" tagName="footer"/>
<add tagPrefix="ControlVendor" assembly="ControlVendorAssembly"/>
</controls>
</pages>
link explaining the additions to the web.config file (please note this article does not address my problem directly)
http://weblogs.asp.net/scottgu/archive/2006/11/26/tip-trick-how-to-register-user-controls-and-custom-controls-in-web-config.aspx
I dont personally feel the 'site wide' declaration of my custom control should be required, but it fixes the problem so I'm using it, but would still like to me enlightened as to the reason why it is required to be done that way.
I have couple of update panels and jquery tabs on page. And also I am loading couple user controls on update panels. After user waited for couple of minutes (not checked the time approx 40 mins). when user send request from submit button it is giving below error?
'Sys.WebForms.PageRequestManagerServerErrorException:
Sys.WebForms.PageRequestManagerServerErrorException: An unknown
error occurred while processing the request on the server. The status
code returned from the server was: 0' when calling method:
[nsIDOMEventListener::handleEvent]
I am not able trace this issue to fix. But I am sure. This is causing by Ajax. Gurus, if you knows solution. Please let me know.
This issue sometimes occurs when you have a control registered as an AsyncPostbackTrigger in multiple update panels.
If that's not the problem, try adding the following right after the script manager declaration, which I found in this post by manowar83, which copies and slightly modifies this post by larryw:
<script type="text/javascript" language="javascript">
Sys.WebForms.PageRequestManager.getInstance().add_endRequest(EndRequestHandler);
function EndRequestHandler(sender, args){
if (args.get_error() != undefined){
args.set_errorHandled(true);
}
}
</script>
There are a few more solutions discussed here: http://forums.asp.net/t/1066976.aspx/9/10
I had this issue and I spent hours trying to fix it.
The solution ticked as answered will not fix the error only handle it.
The best approach is to check the IIS log files and the error should be there. It appears that the update panel encapsulates the real error and outputs it as a 'javascript error'.
For instance my error was that I forgot to make a class [Serializable]. Although this worked fine locally it did not work when deployed on the server.
I got this error when I had my button in the GridView in an UpdatePanel... deubbing my code I found that the above error is caused because of another internal error "A potentially dangerous Request.Form value was detected from the client"
Finally I figured out that one of my TextBoxes on the page has XML/HTML content and this in-turn causing above error
when I removed the xml/HTML and tested the button click ... it worked as expected.
I have got the same issue, here I give my problem and my solution hoping this would help someone:
Following other people recommendation I went to the log of the server (Windows Server 2012 in my case) in :
Control Panel -> Administrative Tools -> Event Viewer
Then in the left side:
Windows Logs -> Application:
In the warnings I found the message from my site and in my case it was due to a null reference:
*Exception type: NullReferenceException
Exception message: Object reference not set to an instance of an object.*
And checking at the function described in the log I found a non initialized object and that was it.
So it could be a null reference exception in the code.
Hope someone find this useful, greetings.
Brother this piece of code is not a solution just change it to
<script type="text/javascript" language="javascript">
Sys.WebForms.PageRequestManager.getInstance().add_endRequest(EndRequestHandler);
function EndRequestHandler(sender, args){
if (args.get_error() != undefined){
**alert(args.get_error().message.substr(args.get_error().name.length + 2));**
args.set_errorHandled(true);
}
}
</script>
and you will see the error is there but you are just not throwing it on UI.
This solution is helpful too:
Add validateRequest="false" in the <%# Page directive.
This is because ASP.net examines input from the browser for dangerous values. More info in this link
I also faced the same issue , and none of these worked. In my case this was fixed by adding these lines in config file.
<appSettings>
<add key="aspnet:MaxHttpCollectionKeys" value="100000" />
</appSettings>
<system.web.extensions>
<scripting>
<scriptResourceHandler enableCompression="false" enableCaching="true"/>
</scripting>
</system.web.extensions>
This is not the real problem, if you want to see why this is happening then please go to error log file of IIS.
in case of visual studio kindly navigate to:
C:\Users\User\Documents\IISExpress\TraceLogFiles\[your project name]\.
arrange file here in datewise descending and then open very first file.
it will look like:
now scroll down to bottom to see the GENERAL_RESPONSE_ENTITY_BUFFER
it is the actual problem. now solve it the above problem will solve automatically.
For those using the internal IIS of Visual Studio, try the following:
Generate the error message.
Break the debugger at the error display.
Check the callstack. You should see 'raise'.
Double click 'raise'.
Check the internals of 'sender' parameter. You will see a '_xmlHttpRequest' property.
Open the '_xmlHttpRequest' property, and you'll see a 'response' property.
The 'response' property will have the actual message.
I hope this helps someone out there!
Check your Application Event Log - my issue was Telerik RadCompression HTTP Module which I disabled in the Web.config.
#JS5 , I also faced the same issue as you: ImageButton causing exceptions inside UpdatePanel only on production server and IE. After some research I found this:
There is an issue with ImageButtons and UpdatePanels. The update to
.NET 4.5 is fixed there. It has something to do with Microsoft
changed the x,y axis of a button click from Int to Double so you can
tell where on the button you clicked and it's throwing a conversion
error.
Source
I'm using NetFramework 2.0 and IIS 6, so, the suggested solution was to downgrade IE compatibility adding a meta tag:
<meta http-equiv="X-UA-Compatible" content="IE=9" />
I've done this via Page_Load method only on the page I needed to:
Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
Dim tag As HtmlMeta = New HtmlMeta()
tag.HttpEquiv = "X-UA-Compatible"
tag.Content = "IE=9"
Header.Controls.Add(tag)
End Sub
Hope this helps someone.
I had the same issue, when i was trying out a way to solve it, i found out that the update panel was causing this issue. Depending on my requirement i could remove the update panel and get rid of the issue.
So it's a possible solution for the issue.
We also faced the same issue, and the problem could only be reproduced in the server (i.e., not locally, which made it even harder to fix, because we could not debug the application), and when using IE. We had a page with an update panel, and within this update panel a modalpopupextender, which also contained an update panel. After trying several solutions that did not work, we fix it by replacing every imagebutton within the modalpopupextender with a linkbutton, and within it the image needed.
Use the following code below inside updatepanel.
<script type="text/javascript" language="javascript">
Sys.WebForms.PageRequestManager.getInstance().add_endRequest(EndRequestHandler);
function EndRequestHandler(sender, args){
if (args.get_error() != undefined){
args.set_errorHandled(true);
}
}
</script>
For me the problem was that I was using a <button> instead of a <asp:LinkButton>
Some times due to some code you get HTML tags in a text filed, like I was replacing some characters with new line BR tag of HTML and by mistake I also replaced it in the text that was supposed to be displayed in a Multiline text box so my multiline text box had a new line HTML tag BR in it coming dynamically due to my string replace function and I started getting this JavaScript error and as this HTML code was displayed in a text box that was in an update panel I start getting this error so I made the correction and all was fine. So before copying pasting anything please look at your code and see that all tag are closed proper and no irrelevant code data is coming to text boxes or Drop down lists. This error always come due to ill formed tags and irrelevant data.
My fix for this was to remove any HTML markup that was in the Text="" property of a TextBox in my asp.net code, inside an update panel. If you have more than one update panel on a page, it will affect them all, which makes it harder to work out which panel has the issue. Chris's answer above lead me to find this, but his is a very hidden answer but I think a very relevant one so here is an answer explained.
<asp:TextBox ID="bookingTBox" runat="server" ToolTip="" Width="150px" Text="<Auto Assigned>" CssClass="textboxItalicFormat"></asp:TextBox>
The above code will give this error.
The below will not.
<asp:TextBox ID="bookingTBox" runat="server" ToolTip="" Width="150px" Text="Auto Assigned" CssClass="textboxItalicFormat"></asp:TextBox>
In the second textbox code I have removed the < and > from the Text="" property. Please try this before spending time adding lines of script code, etc.
Had this problem when using AsyncFileUploader in an iFrame. Error came when using firefox. Worked in chrome just fine. It seemed like either the parent page or iframe page was loading out of sync and the parent page could not find the controls on the iframe page. Added a simple javascript alert to say that the file was uploaded. This gave the controls enough time to load and since the controls were available, everything loaded without an error.
I had this issue when I upgraded my project to 4.5 framework and the GridView had Empty Data Template. Something changed and the following statement which previously was returning the Empty Data Template was now returning the Header Row.
GridViewRow dr = (GridViewRow)this.grdViewRoleMembership.Controls[0].Controls[0];
I changed it to below and the error went away and the GridView started working as expected.
GridViewRow dr = (GridViewRow)this.grdViewRoleMembership.Controls[0].Controls[1];
I hope this helps someone.
This issue for me was caused by a database mapping error.
I attempted to use a select() call on a datasource with errors in the code behind. My controls were within an update panel and the actual cause was hidden.
Usually, if you can temporarily remove the update panel, asp.net will return a more useful error message.
" 1- Go to the web.config of your application "
" 2- Add a new entry under < system.web > "
3- Also Find the pages tag and set validateRequest=False
Only this works for me. !!
Be sure to put tilde and forward slash(~/) when CDN is the root directory. I think it's an issue in IIS
as my friend #RaviKumar mentioned above one reason of following problem is that some piece of data transferred from code to UI contain raw html tags which make request invalid for example I had a textarea and in my code I had set its value by code below
txtAgreement.Text = Data.Agreement
And when I compiled the page I could see raw html tag inside textarea so I changed textarea to div on which innerhtml works and render html (instead of injecting raw html tags into element) and it worked for me
happy coding
<add key="aspnet:MaxHttpCollectionKeys" value="100000"/ >
Add above key to Web.config or App.config to remove this error.
I got this error when I had ModalPopupExtender in the update panel... deubbing my code I found that the above error is caused because of updatepanel updatemode is conditional... so i change it to always then problem is solved.
This was working fine in my code.. i solved my issue.. really
Add below code in web.config file.
<system.web>
<httpRuntime executionTimeout="999" maxRequestLength="2097151"/>
</system.web>
answer for me was to fix a gridview control which contained a template field that had a dropdownlist which was loaded with a monstrous amount of selectable items- i replaced the DDL with a label field whose data is generated from a function. (i was originally going to allow gridview editing, but have switched to allowing edits on a separate panel displaying the DDL for that field for just that record). hope this might help someone.
This error: Uncaught Sys.WebForms.PageRequestManagerServerErrorException ....
i got in backend logic of one UpdatePanel when Oracle made exception because of mispelled column/table in sql command....
I am facing a problem: I have taken a dropdownList control and ID is
drpDownCountries in an ASP.NET project. The dropdownlist control is placed on page, in the code behind file of C#, while typing the control name drpDownCountries, this control ID is listed in object member list.
The code-behind code looks like this:
drpDownCountries.Attributes.Add("onBlur", "ErrorHighlight('" + drpDownCountries.ClientID + "','" + lblCountry.ClientID + "');");
But when I compile the project I am getting the following error:
Error: The name 'drpDownCountries' does not exist in the current context
I have checked this thing on different machines too, and the same error is occurring. I do not understand what the reason is or how to fix it.
Right-click on the ASPX (or ascx) file, and select Convert to web application (or something like that). That will force a refresh on the designer file.
I had this same problem and what worked for me was to make a change to the .ascx file in Design view and then save it. This finally forced Visual Studio to regenerate the designer.cs file and include my new control.
I have seen this error occur when there is a copy of the .aspx page in the project folder.
Example:
Error occurs in Test.aspx.
There is a Test-copy.aspx file in the project folder.
Delete, rename with a different extension, or move Test-copy.aspx to a different folder.
Error is resolved.
It's possible there is an error in your aspx/aspx file that is causing the designer file not to be updated correctly. You could confirm this by adding something new (eg. "") and see if you can access that. If not, something is probably broken in the markup that you'll need to fix.
So first check that your ascx document is defined like so
ExampleClass.ascx
<%# Control Language="C#" AutoEventWireup="true" CodeFile="ExampleClass.ascx.cs" Inherits="ExampleClass" %>
ExampleClass.ascx.cs
public partial class ExampleClass : System.Web.UI.UserControl
{
protected void Page_Load(object sender, System.EventArgs e)
{
}
}
In aspx this type of error often occurs when you miss runat="server"
Do not let Intellisense fool you. Sometimes (usually after fixing problems with duplicate class names), you simply need to rebuild the project and the reported errors go away. Reopening the file after the build might be necessary.
You should put some code to get help..
Anyway, the problem could be that drpDownCountries is contained within a Panel control.
The Panel control is a Container control, in that it can hold lots of
controls.
In order to access the controls within that Panel control,
you first need to "help" ASP.Net to find it.
The typical way of doing this is to use the FindControl method look here.
Code sample:
DropDownList myDrop = (DropDownList)this.Panel1.FindControl("drpDownCountries");
if(myDrop != null)
{
..somecode..
}
Recreate the project. Just create a new project and add the elements one by one and hope it won't happen again. If it does, well that's part of the Microsoft experience: recreate another project and so on, until you decide to quit your job and join open-source.
CORRECTION
I'm going to redo the project that I have been working on since the last 3 days using ASP .NET MVC. I should be using an open-source tech for sure, but too bad it's not my decision for this project to not use .NET.
If this is happening after copy/move pages to new location, or project, you may simply check if PageName.ascx.designer.cs is included in project.
There is a bug in visual studio (or maybe reshrper): It includes PageName.ascx and PageName.ascx.cs, but not PageName.ascx.designer.cs, which must be included manually.
The only thing that worked for me was to add a temp controller in the aspx file and saving it.
That generated the designer again, and my controllers are now recognized!
You can then remove the temp controller and save; it won't ruin anything.
after weeks of having this issue I finally decided to ask for a solution to the following problem:
In the .aspx page you can set
<%# MasterType VirtualPath="~/Mastername.master" %>
This results in an auto generated property in the .aspx.designer
public new Mastername Master {
get {
return ((Masternamee)(base.Master));
}
}
Works perfectly fine. But if I do changes in the .aspx file, the property will be new auto generated and it looks like the following:
public new NAMESPACE1.Mastername Master {
get {
return ((NAMESPACE1.Mastername)(base.Master));
}
}
Compiling will not be possible afterwards, because the class for the MasterPage cannot be resolved at the given namespace.
The masterpage has NAMESPACE1 as namespace.
Every contentpage has the same NAMESPACE1.
The autogenerated property tries to look for the masterpage class in NAMESPACE1.NAMESPACE1 which will fail, due to it does not exist. Of course I can remove the first NAMESPACE1. to make the app compilable again, but it just sucks to do this nearly every time I make changes in the .aspx file.
Is there a way to avoid this problem? The only way I can think of, is to ignore the auto generated property and make a explicit cast everytime I want have access to the masterpage.
Edit: I'm using Visual Studio 2008 Professional SP1.
For some reason the designer believes that the master page is defined in namespace NAMESPACE1, so look at the master page definition (and code behind) to check its namespace has not been modified (possibly accidentally).
If there is nothing obvious, a search in all files (*.cs, *.aspx, *.master, ...) for NAMESPACE1 may be needed.
(This is where using a VCS would help --- you could check the history of changes.)
Actually it's more a designer "feature". ;-)
The Master name used in your designer file will be pulled from your .Master file's Inherits property. So change how you qualify the Inherits attribute, and that will change the class name used when the designer file is created.
I found a solution that works. I won't use the autogenerated property in the designerfile. I'll write my own wrapper property that I do implement in every contentpage.
I had this same problem when I added <%# MasterType VirtualPath="~/TestMaster.Master" %> to my aspx page in SOURCE view. For some reason, the page never created correctly and kept giving me invalid namespace errors until I actually changed to DESIGN view and resized a control and finally the error went away. Somewhere it was using some cached data (even a Build/Clean Solution didn't clear it out) and until the designer recreates the page, it generates that error.
Change
<%# MasterType VirtualPath="~/Mastername.master" %>
to
<%# MasterType TypeName="Mastername" %>
this will work perfectly