Ok, so I've got a template field in a gridview that contains just a simple button...
<%# Page Language="C#" AutoEventWireup="true" CodeFile="Administration.aspx.cs"
Inherits="Administration" %>
<%# Register TagPrefix="ajaxToolkit" Namespace="AjaxControlToolkit" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Keywords Administration</title>
</head>
<body class="popupbody">
<form id="form1" runat="server">
<ajaxToolkit:ToolkitScriptManager ID="ToolkitScriptManager1" runat="server" EnablePartialRendering="true" CombineScripts="false"></ajaxToolkit:ToolkitScriptManager>
<asp:Label ID="AddLabel" runat="server">Add a Keyword</asp:Label>
<br />
<asp:TextBox ID="AddTextBox" runat="server" />
<asp:Button ID="AddButton" Text="Add" runat="server" OnClick="AddKeyword_Click" />
<asp:GridView ID="KeywordsGridView" AllowPaging="false" AutoGenerateColumns="false" BackColor="white"
GridLines="None" HeaderStyle-CssClass="Table_Header" RowStyle-CssClass="Table_Style"
OnRowDataBound="RowBound" runat="server">
<Columns>
<asp:TemplateField>
<ItemTemplate>
<asp:Button runat="server" />
</ItemTemplate>
</asp:TemplateField>
<asp:BoundField DataField="References" SortExpression="References" HeaderText="Total References" />
<asp:BoundField DataField="Keyword" SortExpression="Keyword" HeaderText="Keyword" />
</Columns>
</asp:GridView>
</form>
</body>
</html>
Whenever I click the button I get the error...
Invalid postback or callback argument. Event validation is enabled using
<pages enableEventValidation="true"/> in configuration or <%# Page
EnableEventValidation="true" %> in a page. For security purposes, this feature
verifies that arguments to postback or callback events originate from the server
control that originally rendered them. If the data is valid and expected, use the
ClientScriptManager.RegisterForEventValidation method in order to register the
postback or callback data for validation.
I've found a decent amount of articles referencing this issue, including a couple on SO, for example...
Invalid postback or callback argument. Event validation is enabled using '<pages enableEventValidation="true"/>'
and...
Invalid postback or callback argument
I might just be misunderstanding, but as far as I can tell they don't really help me. How do I get this to go away without setting enableEventValidation="false"?
EDIT Posted all the code for my page.
I know this post is old, but I also had this problem recently.
After checking the how the code was generated for the asp:ButtonField and also for the asp:Button that I have added in an ItemTemplate I discovered quite a big difference:
asp:ButtonField:
input type="button" onclick="javascript:__doPostBack('ctl00$ctl00$cphMain$cphContent$gvEmails','SendFromBatch$0')" value="Continue">
asp:Button:
input id="ctl00_ctl00_cphMain_cphContent_gvEmails_ctl02_btnCont" type="submit" onclick="FreezeScreen('Emails are being sent...');" value="Continue" name="ctl00$ctl00$cphMain$cphContent$gvEmails$ctl02$btnCont">
The Type was the problem! So, after i changed the UseSubmitBehavior from "Submit" to "False" I did not get the error anymore.
EDIT:
I recently wanted to change from the normal btns to imgBtns so that I can save some space and also make the gridview nicer :D. Of course I had the same problem popping up and the imagebtn does not have UseSubmitBehavior property, so I started looking after a solution.
Found the following (The code below is in a UserControl).
1) Bind in !IsPostBack
2) Register the usercontrol itself in the Render
and everything works just as planned - no validation errors.
protected void Page_Load(object sender, EventArgs e)
{
OnLoadingEvent(new EventArgs());
if (!Page.IsPostBack)
{
gvEmails.DataSource = odsEmails;
try
{
gvEmails.DataBind();
}
catch (Exception)
{
}
}
if (!writeText) divWriteEmail.Visible = false;
}
protected override void Render(HtmlTextWriter writer)
{
Page.ClientScript.RegisterForEventValidation(this.UniqueID);
base.Render(writer);
}
EDIT:
I was playing around with the code above and asked myself, what if you actually need to rebing your objectdatasource - what happens then? Well the code above will not work if you rebind in the page load, because the gridview will be rebound again when you click a btn in the gridview's row and it will not be recognized as being generated on the server. Fair and square, but how to avoid this behaviour? Well... i figured out a way, maybe not the best but it does the trick.
Actually, you do not want to rebind the gridview when you click a btn on the gv's row... but how do we know that since the page load method is first called? Well, actually i do not want to rebind the gridview if the select param of the object data source do not change. So, I keep the select param of the objectDataSource in the session view and I rebind my gridview only when one of them changes - this behaviour is only during the PageLoad event. In order to see latest rows i click refresh and get the latest rows with no problem and at the moment i click a gvRow btn, the error dissapears.
To make all of this happen you have to
Directly call the .Select() of the object data source
Catch the OnSelecting event from the datasource, save the select param set the e.Cancel = true
Check if the select param are different and then bind the gridview and this time when catching the OnSelecting you have to set e.Cancel = false in order to retrieve the data from the DB - only one time.
Hope this helps!
This fellow found a solution to a similar problem (scroll down to about the 4th comment), which was to set unique id's for the GridView buttons.
I had the similar error today but with a different solution. I've worked with gridviews for years now and never had the issue so I figured it must be something stupid. Turns out I had forgotten to put my code that loads the gridview into a if(!Page.IsPostBack) block which caused the button to be recreated after I clicked it, thus causing the error. Placing the loading code in said block eliminated the issue.
You need to give your button an ID. Just a runat="server" does not meet the minimum information that needs to be provided for a server control to be created.
Related
Got weird problem. I have simple page with TextBox:
<asp:ScriptManager runat="server" />
<asp:UpdatePanel runat="server">
<ContentTemplate>
<asp:TextBox ID="amountTextBox" runat="server" TextMode="Number" />
<asp:Button runat="server" Text="Confirm" OnClick="confirmButton_Click" />
</ContentTemplate>
</asp:UpdatePanel>
After Button click I try to get TextBox value:
public partial class test : Page {
protected void confirmButton_Click(object sender, EventArgs e) {
var answer = amountTextBox.Text;
}
}
but it's empty. If I remove UpdatePanel, I manage to get the value. If I leave UpdatePanel and remove TextMode property, I manage to get the value. But why can't I have TextBoxt with TextMode set to Number in UpdatePanel?
It is a known issue, a fix is available in .NET 4.5 RTM.
Description
HTML5 has new types for the input tag, such as type="number", which is
needed to make mobile phones display a numerical keyboard instead of a
text keyboard. When doing a full postback of the page it works in all
browsers. But if I puts these in an updatepanel on a website to do a
partical postback, then none of the new HTML input types are included
in the postback response to the server from those browsers that
understands these new types (Safari/WebKit and Opera). It works
correctly in IE8 and Firefox 4, but probably only because they have
not implemented these new types and falls back to understanding it as
a type="text" field.
Here is another question with this issue and workarounds: UpdatePanel with input type other than text in html5.
Ok, I've already learned that in order to keep the dynamic (created) controls and their viewstate in asp.net we must (re)create them in the Page init event, so they already exist within the page's control hierarchy before the view state is loaded.
As it says in this article.
There is no problem to achieve this behaviour if the criteria to create these controls is outside the web environment, for example a database. But what should I do if what I use to decide how many dynamic controls I have to create is actually a value that is in the controls?
I try to explain it with an example, maybe it's clearer:
Let's say that we have a textbox and two buttons. In the textbox I write the number of how many dynamic controls I want to create, for example 4 checkbox. When I hit the button1 the controls should be created. No problem. Then I check some checkboxes and hit the button2 just to fire a postback. Now I should recreate the controls in the page init event, like we said before, in order to maintain the controls and their state.
And here comes the problem. Because of I'm in the init stage I have no viewstate so I'm no able to access the value in the textbox that tells me how many dynamic checkbox should I create.
I thought that storing the value in the session object would do the trick, but it doesn't. The session object is no accessible as well.
Where can I save the value that it'll be accessible from the init event too?
Thanks and sorry for the long post!
First thing - textbox value is not stored/retrieved from view state, you cannot get textbox value from viewstate.
Coming to actual problem, here is the sequence of (imp) events init -> load view state -> bind postback data -> page load. You can retrieve textbox value only after bind postback data event (which actually takes posted data and binds to the textbox control).
In init only option is to use Request.Form{"textboxid"] to get the textbox value.
You are on the right track.
If you use TextBox, you do not need another ViewState to keep track of how many controls has been created, because TextBox control has its own ViewState already.
You can use either Page_Init or Page_Load to load control back.
<%# Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs"
Inherits="WebApplication2010.WebForm1" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:TextBox runat="server" ID="NumberTextBox" />
<asp:Button runat="server" ID="CreateControlButton"
OnClick="CreateControlButton_Click"
Text="Create Control" />
<br />
<asp:PlaceHolder runat="server" ID="PlaceHolder1"></asp:PlaceHolder>
</div>
</form>
</body>
</html>
using System;
using System.Web.UI;
namespace WebApplication2010
{
public partial class WebForm1 : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
if (IsPostBack)
{
int ids;
if (Int32.TryParse(NumberTextBox.Text, out ids))
{
for (int i = 0; i < ids; i++)
{
Control ctrl = Page.LoadControl("WebUserControl.ascx");
ctrl.ID = i.ToString();
PlaceHolder1.Controls.Add(ctrl);
}
}
}
}
protected void CreateControlButton_Click(object sender, EventArgs e)
{
}
}
}
<%# Control Language="C#" AutoEventWireup="true"
CodeBehind="WebUserControl.ascx.cs"
Inherits="WebApplication2010.WebUserControl" %>
<asp:CheckBox runat="server" ID="CheckBox1" />
<asp:Button runat="server" ID="Button1" OnClick="Button_Click"
Text="Post Back" />
<asp:Label runat="server" ID="Label1" />
<br />
using System;
namespace WebApplication2010
{
public partial class WebUserControl : System.Web.UI.UserControl
{
protected void Button_Click(object sender, EventArgs e)
{
Label1.Text = " This control was posted back.";
}
}
}
This is the common paradox with page lifecycle when you work with code behind. For example, you save the editing customerid in viewstate but controls need to bind on init to be able to read their posted values.
Best real life solution is to do what bound controls do on postback, call explicilately the LoadPostBackData on IPostBackDataHandler interface that all controls implement, after you have created them in Page Load event.
You should create an extension method for Controls and call it when needed:
control.DataBind();
control.LoadPostedData(); // extension method
I have a DropDownList object in my web page. When I click on it and select a different value, nothing happens, even though I have a function wired up to the SelectedIndexChanged event.
First, the actual object's HTML code:
<asp:DropDownList ID="logList" runat="server"
onselectedindexchanged="itemSelected">
</asp:DropDownList>
And this is that function, itemSelected:
protected void itemSelected(object sender, EventArgs e)
{
Response.Write("Getting clicked; " + sender.GetType().ToString());
FileInfo selectedfile;
Response.Write("<script>alert('Hello')</script>");
foreach (FileInfo file in logs)
{
if (file.Name == logList.Items[logList.SelectedIndex].Text)
{
Response.Write("<script>alert('Hello')</script>");
}
}
}
None of the Responses appear, and that portion of JavaScript is never run. I've tried this on the latest 3.6 version of Firefox, as well as Internet Explorer 8. This is being served from a Windows Server 2003 R2 machine, running ASP.NET with the .NET Framework version 4.
Set DropDownList AutoPostBack property to true.
Eg:
<asp:DropDownList ID="logList" runat="server" AutoPostBack="True"
onselectedindexchanged="itemSelected">
</asp:DropDownList>
try setting AutoPostBack="True" on the DropDownList.
I know its bit older post, but still i would like to add up something to the answers above.
There might be some situation where in, the "value" of more than one items in the dropdown list is duplicated/same. So, make sure that you have no repeated values in the list items to trigger this "onselectedindexchanged" event
Add property ViewStateMode="Enabled" and EnableViewState="true"
And AutoPostBack="true" in drop DropDownList
Also make sure the page is valid.
You can check this in the browsers developer tools (F12)
In the Console tab select the correct Target/Frame and check for the [Page_IsValid] property
If the page is not valid the form will not submit and therefore not fire the event.
For me answer was aspx page attribute, i added Async="true" to page attributes and this solved my problem.
<%# Page Language="C#" MasterPageFile="~/MasterPage/Reports.Master".....
AutoEventWireup="true" Async="true" %>
This is the structure of my update panel
<div>
<asp:UpdatePanel ID="updt" runat="server">
<ContentTemplate>
<asp:DropDownList ID="id" runat="server" AutoPostBack="true" onselectedindexchanged="your server side function" />
</ContentTemplate>
</asp:UpdatePanel>
</div>
Instead of what you have written, you can write it directly in the SelectedIndexChanged event of the dropdownlist control, e.g.
protected void ddlleavetype_SelectedIndexChanged(object sender, EventArgs e)
{
//code goes here
}
The Scenario:
I have an ASP.Net webpage which I intend to use for letting the user(not the real users, but content manager basically) insert and edit the records in a table using a FormView. This FormView is inside an UpdatePanel, as I'm also using cascading dropdownlists to let the user select some values.
Now, this FormView also contains 4 FileUpload controls, and as you might know that these fileupload controls require a full postback since most browsers do not let Javascript access the disk. So, this problem would have been solved by doing something like:
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<Triggers>
<asp:PostBackTrigger ControlID="InsertButton" />
<asp:PostBackTrigger ControlID="UpdateButton" />
</Triggers>
<ContentTemplate>....</ContentTemplate>
</asp:UpdatePanel>
Edit: Forgot to add that the fileuploading takes place in the OnUpdating and OnInserting events of the SqlDataSource.
The Problem:
Since the InsertButton and the UpdateButton reside inside the Formview, I cannot directly access their ID's through markup. And MSDN says that:
Programmatically adding
PostBackTrigger controls is not
supported.
Please suggest some solution to make this work. Any insight on the matter is highly appreciated. Thanks.
P.S.- A workable solution for me was to set the UpdatePanel's PostBackTrigger as the whole FormView itself:
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<Triggers>
<asp:PostBackTrigger ControlID="FormView1" />
</Triggers>
<ContentTemplate>....</ContentTemplate>
</asp:UpdatePanel>
But now due to a bit of change in requirements, this solution(if you call it a solution) is not acceptable.
Have you given a though about using Iframe for doing the postback ? something like:
<iframe name="uploader" id=uploader
src="uploaderSender.aspx?AllowedExtension=<%= AllowedExtension %>&StoringPath=<%= StoringPath %>&StoringFileName=<%= StoringFileName %>&OldFileName=<%= OldFileName %>&MaximumSize=<%= MaximumSize %>"
width="450" height="50" frameborder=0 scrolling=no >
</iframe>
with uploaderSender.aspx like :
<form action="UploaderReceiver.aspx" method="post" enctype="multipart/form-data">
<input type="file" name="file" id="file" onchange="document.getElementById('IsFileUploading').style.visibility = 'visible'; document.forms[0].submit()"/>
<span id="IsFileUploading" style="visibility: hidden">
<asp:Image ID="Image1" runat="server" ImageUrl="~/immagini/Ajax-loader.gif" />
</span>
</form>
and UploaderReceiver.aspx like :
protected void Page_Load(object sender, EventArgs e)
{
//if there is one file to process
if (Request.Files.Count > 0)
//create the folder if it does'nt exists and returns the local path to get it
string StoringPathToBeSaved = StoringPath.GetFolderPath();
// append the name of the file to upload to the path.
StoringPathToBeSaved = StoringPathToBeSaved + StoringFileName + Extension;
Request.Files[0].SaveAs(StoringPathToBeSaved);
}
this is just bits of code just for you to figure out if you would be interested in this way of dealing with the upload, I can give you more if you want after.
see you, and good luck with your code,
Yay!! Finally got it to work!
Here's How:
Well contrary to what MSDN says, we can in fact add PostBack Triggers Programmatically. Not necessarily to the UpdatePanel, but to the ScriptManager.
After hours of playing around, here's what worked:
We are not able to access controls inside a FormView, untill the template has been rendered, so we can only add postback triggers after the formview's OnDataBound Event.
protected void FormView1_DataBound(object sender, EventArgs e)
{
if (FormView1.CurrentMode == FormViewMode.Edit)
{
LinkButton lb = (LinkButton)FormView1.FindControl("UpdateButton");
ScriptManager.GetCurrent(Page).RegisterPostBackControl(lb);
}
//Similarily you can put register the Insert LinkButton as well.
}
And now, if your UpdatePanel causes ConditionalUpdate, you can do something like this to make it work:
The Markup:
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>..
<EditItemTemplate>
...
<asp:LinkButton ID="UpdateButton" runat="server" CausesValidation="True" OnClick="Cause_PostBack"CommandName="Update">Update</asp:LinkButton>
...
</EditItemTemplate>
..</ContentTemplate>
</asp:UpdatePanel>
CodeBehind:
//call this function as the OnClick Event Handler for the Controls you want to register as
//triggers.
protected void Cause_PostBack()
{
UpdatePanel1.Update();
}
Otherwise, if your situation allows it(as mine does), just set the UpdatePanel's UpdateMode="Always"
This is old, but was trying to solve another problem and ran into this. This wasn't my problem, but here's an alternative for anyone new who runs into this as well.
You stated your problem as:
Since the InsertButton and the UpdateButton reside inside the Formview, I cannot directly access their ID's through markup
You actually can access their ID's through markup to use as the ControlID in the PostBackTrigger. You just have to use the button's name that is created in the page html mark-up as the ControlID. You can find the name created by viewing the page source when you're viewing the page in the browser. It typically is the name of the FormView + $ + name of the button.
For example, let's say you have a FormView named "FormView1" that contains an Insert button which you gave the ID of "btnInsert" during design. If you open up your page in the browser to view it live and then view the page's source, you'll notice that the html mark-up of the button will actually be given the name "FormView1$btnInsert".
Use that name as the ControlID in your PostBackTrigger and your update panel will work.
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<Triggers>
<asp:PostBackTrigger ControlID="FormView1$btnInsert" />
</Triggers>
<ContentTemplate>....</ContentTemplate>
</asp:UpdatePanel>
I have a user control embedded in a web part. It has the following snippets of code:
protected TextBox searchTextBox;
protected Button goButton;
protected Button nextButton;
protected Repeater pushpins;
protected Label currentPageLabel;
protected void goButton_Click(object sender, EventArgs e)
{
// Do stuff
}
<asp:TextBox ID="searchTextBox" runat="server" />
<asp:Button ID="goButton" runat="server" Text="Go" OnClick="goButton_Click" />
<asp:Repeater ID="pushpins" runat="server" EnableViewState="false">
<ItemTemplate>Blah</ItemTemplate>
</asp:Repeater>
<asp:Label ID="currentPageLabel" runat="server" />
<asp:Button ID="nextButton" runat="server" Text=" >> " OnClick="nextButton_Click" />
(There is no OnLoad or CreateChildControls method.)
If I place a breakpoint on the first line of goButton_Click, I find:
searchTextBox: initialised
goButton: initialised
nextButton: NULL
pushpins: initialised
currentPageLabel: NULL
Why are some controls initialised and others not? How do I get around this if I'd like to update the Text property on currentPageLabel?
Update:
I've placed breakpoints all the way through the page life cycle and found that nextButton and currentPageLabel are never initialised. The breakpoints were placed at OnLoad, CreateChildControls, goButton_Click, OnPreRender, Render and OnUnload.
Is it possible you've inadvertently got local variables named currentPageLabel and/or nextButton declared somewhere? The compiler will happily allow this...
This is especially common in a move from ASP.NET 1.1 to 2.0 or higher, since the way the designer defined these controls changed.
The problem was that all of the controls that weren't being initialised were inside a HeaderTemplate within a Repeater control. (To save space I didn't paste all of my code into the question, dang it.)
I moved them out and the problem is resolved. Obviously controls in the HeaderTemplate are instantiated by the Repeater and do not follow the normal page life cycle.