i have a class that is teaching asp.net in visual studio (i use the 2022 version). For now we are focusing on Design mode but for some reason my Design mode is broken.
Everytime i use the Wizard tool (only one that i know of) it keeps saying "Error Rendering Control" here is a pic of the Error
my code doesn't have any problem because when i run it in the browser it works and when i gave the files to a few of my classmates it seems to be working for them too.
i would really appreciate any help you can give cause this is driving me nuts.
This is my code if you'd want to test it yourself.
ASP:
<%# Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="WebApplication3.WebForm1" %>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:Panel ID="Panel1" runat="server">
<asp:Wizard ID="Wizard1" runat="server" ActiveStepIndex="0" OnFinishedButtonClick="Wizard1_FinishButtonClick1" Width="500px" FinishCompleteButtonText="Finish" FinishPreviousButtonText="Back" StartNextButtonText="Next" StepNextButtonText="Next">
<WizardSteps>
<asp:WizardStep ID="WizardStep1" runat="server" Title="About you">
<asp:Label ID="Label1" runat="server" Text="Name:"></asp:Label>
<asp:TextBox ID="name" runat="server"></asp:TextBox>
</asp:WizardStep>
<asp:WizardStep ID="WizardStep2" runat="server" StepType="Finish" Title="Favorite Language">
<asp:DropDownList ID="FavoriteLanguage" runat="server">
<asp:ListItem>C#</asp:ListItem>
<asp:ListItem>Visual Basic</asp:ListItem>
<asp:ListItem>CSS</asp:ListItem>
</asp:DropDownList>
</asp:WizardStep>
<asp:WizardStep runat="server" StepType="Finish" Title="Ready">
<asp:Label ID="resualt" runat="server" Text="Label"></asp:Label>
<br />
</asp:WizardStep>
</WizardSteps>
</asp:Wizard>
</asp:Panel>
</div>
</form>
</body>
</html>
C#:
`
namespace WebApplication3
{
public partial class WebForm1 : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
resualt.Text = "Your Name:" + name.Text;
resualt.Text += "<br />Your Favorite Language:" + FavoriteLanguage.SelectedValue;
}
}
}
`
i tried reinstalling, repairing and even downgrading to an older version but it won't work. Sometimes after reinstalling it will get fixed but when i close the app and reopen it will break again.
Well, first of all, you don't have a "control of type view" in that page.
However, what I would do is make sure you install all of the bits and parts reuiqred for webforms.
Web forms are somewhat older now, and vs 2022 does not install all of the bits and parts and desingers required for such "older" type of projects based on webforms.
So, launch vs2022, (don't load a project).
Then from tools->Get Tools And features.
You should see this:
(and expand above)
Make sure you select these:
And these:
After that exit, vs, and restart.
Related
I have developed a small form with 3 input type = text and one input type = submit button. The end user fills the form and submit it, but no data inserted into backend table. (probably empty form is submitted). I get to know that Javascript is disabled on user's browser. Now i want to do server side validation. How i validate my form on server side? I need a piece of code to validate form on server side (code behinde) ? I need code in asp.net
You really should not ask for straight forward code on this forum. But either way here is a great resource for asp.net form validation: MSDN - Validating ASP.NET Server Controls
Essentially, assuming you are using C#, you might do something like this:
<%# Page Language="C#" %>
<script runat="server">
void Button1_Click(Object sender, EventArgs e) {
Label1.Text = "Page is valid!";
}
</script>
<html>
<head>
</head>
<body>
<form runat="server">
<p>
<asp:TextBox id="TextBox1"
runat="server"></asp:TextBox>
<asp:RequiredFieldValidator
id="RequiredFieldValidator1" runat="server"
ErrorMessage="Required!"
ControlToValidate="TextBox1">
</asp:RequiredFieldValidator>
</p>
<p>
<asp:Button id="Button1" onclick="Button1_Click"
runat="server" Text="Button"></asp:Button>
</p>
<p>
<asp:Label id="Label1" runat="server"></asp:Label>
</p>
</form>
</body>
</html>
My recommendation is to try and Google some and look for tutorials - there are pretty informative ones out there available with easy step by step directions.
Happy coding!
I have a page with a listview that shows something like posts. On each post there should be a "rate box" which works similar to the "Like" button in facebook. The rate box is a User Control, that has an update panel inside it.
If I put the control with some random values in the page it works great - but when I put it inside the ListView, where it should be located, it won't work. The method is being called, but nothing happens.
I simplified the code a bit to make it easier to understand:
The "rate box" control:
protected void OnRateClick(object sender, ImageClickEventArgs e)
{
Rate++;
RateAmountLiteral.Text = Rate.ToString();
RateButton.Visible = false;
FeedbackLiteral.Visible = true;
rateButtonPanel.Update();
}
ascx:
<div class="rate_div">
<asp:UpdatePanel ID="rateButtonPanel" runat="server" UpdateMode="Conditional">
<ContentTemplate>
<fieldset>
Rate:
<asp:Literal ID="RateAmountLiteral" runat="server"></asp:Literal>
<asp:ImageButton ID="RateButton" runat="server" ImageUrl="icn_rate.png"
OnClick="OnRateClick" />
<asp:Literal ID="FeedbackLiteral" runat="server" Visible="false">Thanks for rating!</asp:Literal>
</fieldset>
</ContentTemplate>
</asp:UpdatePanel>
</div>
aspx (using the control):
<asp:ListView ID="PostsView" runat="server" ItemPlaceholderID="itemPlaceHolder2"
<LayoutTemplate>
<div class="posts_div">
<asp:PlaceHolder ID="itemPlaceHolder2" runat="server" />
</div>
</LayoutTemplate>
<ItemTemplate>
<div class="post_div">
<div class="post_body">
<%# CurrentPost.Body %>
</div>
<UC:RatingBox id="RatingBox" runat="server"
PostID="<%# CurrentPost.ID %>"
Rate="<%# CurrentPost.Rate %>"/>
By: <a href="<%# CurrentPost.Author.LinkToProfile %>">
<%# CurrentPost.Author.DisplayName %>
</a> |
<%# CurrentPost.LiteralTime %>
</div>
</ItemTemplate>
</asp:ListView>
While debugging I noticed the controls in the method "OnRateClick" are empty and don't contain the right values. Please advice.
Also if you have any comments about the way I did things, don't hold yourself.
Thanks
There are a lot things that you may not have set up, I cannot tell from just the code snippet you have given. But make sure you do the following: -
1) Place a ScriptManager "" on the page.
If you are using master page in your application and your web page uses the master page, place script manager in master page. Or alternatively,you can also place script manager on specific web pages anyway.
2) Add a Triggers for the button RateButton in your Update panel.
I've got an ASPX page set up that loads and displays dynamic data from a local SQLite database. Since the data is being written to the database from a separate C# application, I've set up my ASPX page to refresh every 30 seconds when the database has flagged itself as actively receiving new data.
On my ASPX page, I've got a TabContainer with several different TabPanels that each represent a different view of the data. Now, when my page is being refreshed, the active tab panel is being reset to the one set in my ASPX page as the ActiveTabIndex.
I was wondering if there is an easy way to persist which tab is being remembered.
Thanks!
Edited to add code sample
MyPage.aspx
<%# Page Title="" Language="C#" MasterPageFile="~/MasterPageFile.master" AutoEventWireup="true" CodeFile="MyPage.aspx.cs" Inherits="MyPage" %>
<%# Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" TagPrefix="asp" %>
<asp:Content ID="Content1" ContentPlaceHolderID="head" Runat="Server">
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="content" Runat="Server">
<asp:ToolkitScriptManager ID="ToolkitScriptManager" runat="server" />
<asp:TabContainer ID="tabContainer" runat="server" ActiveTabIndex="1" CssClass="myTabStyle" Visible="true">
<asp:TabPanel ID="tab1" runat="server" HeaderText="Tab 1">
<ContentTemplate>
<p>Hello</p>
</ContentTemplate>
</asp:TabPanel>
<asp:TabPanel ID="tab2" runat="server" HeaderText="Tab 2">
<ContentTemplate>
<asp:PlaceHolder ID="tab2placeholder" runat="server" />
</ContentTemplate>
</asp:TabPanel>
<asp:TabPanel ID="tab3" runat="server" HeaderText="Tab 3">
<ContentTemplate>
<asp:TabContainer ID="tab3content" runat="server" ActiveTabIndex="0" CssClass="myTabeStyle" />
</ContentTemplate>
</asp:TabPanel>
<asp:TabPanel ID="tab4" runat="server" HeaderText="Tab 4">
<ContentTemplate>
<p>Blah.</p>
</ContentTemplate>
</asp:TabPanel>
</asp:TabContainer>
</asp:Content>
MyPage.aspx.cs
public partial class MyPage : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
...
if (isInProgress)
{
Response.AddHeader("Refresh", "30");
}
LoadTab1();
LoadTab2();
LoadTab3();
LoadTab4();
...
}
}
Try putting UpdatePanels within in the TabPanels. If you post a code sample of your ASPX it would be easier to help.
If you are doing full postbacks all the time then save it in your ASP.NET session. e.g.
Session["ActiveTab"] = index;
Then to retrieve it:
int? activeTab = Session["ActiveTab"] as int?;
Otherwise using jQuery ajax to refresh the data, is in my experience a much better way to go than using UpdatePanels. But it looks like you are already committed to MS Ajax so go with Mike's recommendation to use an ajax timer instead of a refresh header.
The problem I am facing is that when there is validation on a page and I am trying to display a model pop-up, the pop-up is not getting displayed. And by using fire-bug I have noticed that an error is being thrown.
The button that is used to display the pop-up has cause validation set to false so I am stuck as to what is causing the error.
I have created a sample page to isolate the problem that I am having, any help would be greatly appreciated.
The Error
function () {Array.remove(Page_ValidationSummaries, document.getElementById("ValidationSummary1"));}(function () {var fn = function () {AjaxControlToolkit.ModalPopupBehavior.invokeViaServer("mpeSelectClient", true);Sys.Application.remove_load(fn);};Sys.Application.add_load(fn);}) is not a function
http://localhost:1131/WebForm1.aspx
Line 136
ASP
<%# Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="CLIck10.WebForm1" %>
<%# Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" TagPrefix="ajaxToolkit" %>
<!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">
<asp:ScriptManager ID="ScriptManager1" runat="server">
</asp:ScriptManager>
<div>
<asp:Button ID="btnPush" runat="server" Text="Push" CausesValidation="false" onclick="btnPush_Click" />
<asp:TextBox ID="txtVal" runat="server" />
<asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server" ControlToValidate="txtVal" ErrorMessage="RequiredFieldValidator" />
<asp:ValidationSummary ID="ValidationSummary1" runat="server" />
<asp:Panel ID="pnlSelectClient" Style="display: none" CssClass="box" runat="server">
<asp:UpdatePanel ID="upnlSelectClient" runat="server">
<ContentTemplate>
<asp:Button ID="btnOK" runat="server" UseSubmitBehavior="true" Text="OK" CausesValidation="false" OnClick="btnOK_Click" />
<asp:Button ID="btnCancel" runat="server" Text="Cancel" CausesValidation="false" OnClick="btnCancel_Click" />
</ContentTemplate>
</asp:UpdatePanel>
</asp:Panel>
<input id="popupDummy" runat="server" style="display:none" />
<ajaxToolkit:ModalPopupExtender ID="mpeSelectClient" runat="server"
TargetControlID="popupDummy"
PopupControlID="pnlSelectClient"
OkControlID="popupDummy"
BackgroundCssClass="modalBackground"
CancelControlID="btnCancel"
DropShadow="true" />
</div>
</form>
Code Behind
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
namespace CLIck10
{
public partial class WebForm1 : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void btnOK_Click(object sender, EventArgs e)
{
mpeSelectClient.Hide();
}
protected void btnCancel_Click(object sender, EventArgs e)
{
mpeSelectClient.Hide();
}
protected void btnPush_Click(object sender, EventArgs e)
{
mpeSelectClient.Show();
}
}
}
This is an issue with using both ValidationSummary and ModalPopup.
see here: http://ajaxcontroltoolkit.codeplex.com/WorkItem/View.aspx?WorkItemId=12835
The problem is that there is a missing ";" between the two injected scripts.
Their solution is to create/use a custom server control that inherits from ValidationSummary, that injects a ";" into the page startup script to fix the bug:
[ToolboxData("")]
public class AjaxValidationSummary : ValidationSummary
{
protected override void OnPreRender(EventArgs e)
{
base.OnPreRender(e);
ScriptManager.RegisterStartupScript(this.Page, this.Page.GetType(), this.ClientID, ";", true);
}
}
Try setting your ValidationSummary "Enabled" property to false on this event : "btnPush_Click"
; and then setting it back to enabled = "true" on this events : "btnOK_Click" ,"btnCancel_Click".
I think this will work if you do not have the validation summary inside the Panel that you want to pop up.But it is not a solution if you need the validation summary inside the pop up panel,...witch is my case :(.
Best Regards.
I tried all the available answer online but didn't worked any. Then i tried to move my modal popup extender at very end of the HTML and it works fine for me. Me and my users are Happy :)
I am not using FROM tag I am using Content place holder just like below:
<asp:Content ID="Content1" ContentPlaceHolderID="MainContent" runat="server">
<table id="tblMessage" runat="server" width="100%" >
<tr align="center">
<td align="center">
main content and
<asp:Panel ID="pnlSelectClient" Style="display: none" CssClass="box" runat="server">
<asp:ValidationSummary ID="ValidationSummary1" runat="server" />
<asp:UpdatePanel ID="upnlSelectClient" runat="server">
<ContentTemplate>
<asp:Button ID="btnOK" runat="server" UseSubmitBehavior="true" Text="OK" CausesValidation="false" OnClick="btnOK_Click" />
<asp:Button ID="btnCancel" runat="server" Text="Cancel" CausesValidation="false" OnClick="btnCancel_Click" />
</ContentTemplate>
</asp:UpdatePanel>
</asp:Panel>
If you notice i have validation summary inside the panel because i want error message inside the pop up(i have some additional control in pop up too). and
Some more HTML tag here as i have so many other things to do in one page. right before closing tag of TABLE
<ajaxToolkit:ModalPopupExtender ID="mpeSelectClient" runat="server"
TargetControlID="popupDummy"
PopupControlID="pnlSelectClient"
OkControlID="popupDummy"
BackgroundCssClass="modalBackground"
CancelControlID="btnCancel"
DropShadow="true" />
</table>
Done.it's working. Hope that works for other too.
Are you using validation groups anywhere on the page? I've had problems with control events not firing when they are not part of a validation group and other controls on the page are part of a validation group.
I'd try changing this:
<input id="popupDummy" runat="server" style="display:none" />
to something like this:
<asp:Button id="popupDummy" runat="server" CausesValidation="false" Visible="false" />
I bet the untyped input is requiring validation.
i had the same issue, adding ValidationGroup to the validation controls did the trick!
One other thing to try, if you don't need Client Script you can disable it in the markup. Doing that fixed our problem.
EnableClientScript="false"
Why does the following give me a compilation error for line B (Label2, outside UpdatePanel) but not for line A (Label1, inside UpdatePanel)? I would have expected both lines to give an error since both controls are within the same Repeater and should therefore not be directly accessible outside the repeater, since there is no one unique instance.
<script runat="server">
protected void Page_Load(object sender, EventArgs e)
{
Label1.Text = Label1.ClientID; // Line A - compiles fine
Label2.Text = Label2.ClientID; // Line B - "The name 'Label2' does not exist in the current context"
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Untitled Page</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:ScriptManager ID="ScriptManager1" runat="server" />
<asp:Repeater runat="server" ID="Repeater1">
<ItemTemplate>
<asp:UpdatePanel runat="server" ID="UpdatePanel1">
<ContentTemplate>
<asp:Label ID="Label1" runat="server" Text="Label1" />
</ContentTemplate>
</asp:UpdatePanel>
<asp:Label ID="Label2" runat="server" Text="Label2" />
</ItemTemplate>
</asp:Repeater>
</div>
</form>
</body>
</html>
I'm betting if you comment out line B you'll get a run-time error on execution. Label1 is going to be a null reference.
When you create controls in the ASPX page Visual Studio tries to help you out by adding the controls to the code behind in the designer file which extends the class for the page. In this case it's adding one when it shouldn't be.
Short answer is it's a bug. You should submit it but it shouldn't be a blocking issue.
Real question is why are you creating multiple update panels in a repeater ? Put one outside of the repeater and call it good. Or if you just want to refresh some text dont use an update panel, use a call back with some client side script to set the dom element. Check out this http://encosia.com/2007/07/11/why-aspnet-ajax-updatepanels-are-dangerous/
Neither of those is proper anyway. You shouldn't be trying to directly reference a control that's contained within the ItemTemplate.
If you want to modify those Labels at runtime, you should be using OnItemDataBound and FindControl. To "find" the Label in the UpdatePanel, you'll need to use UpdatePanel.ContentTemplateContainer.FindControl().