I have a question for web service. I have been testing but not sure what is causing this. I am trying to prevent my web page from flickering when there is a post back. So I used web service. It is working fine without any noticeable flickering when I put my dropdownlist on a normal page (without Master page). However, when I moved the same code to page with master page, then the flickering happens. Anyone has any ideas how to fix this please? My html mark up is as below:
<div>
<div>
<asp:DropDownList ID="ddlState" runat="server" AutoPostBack="True"></asp:DropDownList>
</div>
<div>
<asp:DropDownList ID="ddlCity" runat="server" DataTextField="city_name" DataValueField="city_id"></asp:DropDownList>
</div>
</div>
I am trying to avoid using update panel. Thanks
You will get the flikering as long as you have postback, you can use ajax call to refresh only part of page for instance drop down. One of easiest solution is to use UpdatePanel or you can use jQuery ajax. This article explains how you can make cascading dropdowns using jquery ajax with asp.net.
Related
I didn't want to have a ton of code on one page, but to keep the code modular and simple. So in my TabContainer I have the following where each tab refers to a web page and my code is inside each web page. My TabContainer itself is inside the default.aspx page.
<asp:TabContainer ID="tabTOL" runat="server" ActiveTabIndex="0" CssClass="tol">
<asp:TabPanel ID="tabHome" runat="server" TabIndex="0" HeaderText="Home">
<ContentTemplate>
<iframe src="Home.aspx"></iframe>
</ContentTemplate>
</asp:TabPanel>
...
Of course, the problem is that I cannot refer to other tabs or the TabContainer/default page from within any tab. I'm trying to update a TextBox on the default.aspx page from a tab, but there is no reference to it.
Should I bite the bullet and have one huge web page with all the html and code behind? There are a dozen tabs in my TabContainer. I would think this would slow down processing as well. Or, is there a cleaner way to do this and still retain the ability to reference controls on the main page or other tabs?
I'm working in VS2008 and .Net 3.5 and AJAX 3.5.
Thanks!!
Larry
I would suggest that you change the structure of Home.Aspx into a Web User Control (*.ascx). The advantage is that you are now running within the context of the parent page. Therefore all it's functionality is within reach. For example, to acces a textbox on the parent page, from the Home.Ascx, you would do this:
((Default)this.Parent).txtMyTextBox.Text = "Hello";
I have 2 sections of my website I am developing, a reference box that has a fixed width and a working box that has the same height as the content. I am trying to make it so the user can swap the content between the two boxes. I have the following type of setup in the aspx page:
<asp:panel id="pnlReference" runat="server" CssClass="referencePanel" >
<asp:panel id="pnlsection1" runat="server" >
Content....
</asp:panel>
</asp:panel>
<asp:linkbutton id="lbtSwapPanels" runat="server" />
<asp:panel id="pnlWorking" runat="server" CssClass="workingPanel" >
<asp:panel id="pnlSection2" runat="server" >
Content....
</asp:panel>
</asp:panel>
What I am trying to have occur is when I press the lbtSwapPanels linkbutton, it moves pnlSection1 into pnlWorking and pnlSection2 into pnlReference. The code I used to do this in the OnClick method was:
Control pane1, pane2;
pane1 = pnlWorking.Controls[0];
pane2 = pnlReference.Controls[0];
// Remove them from their respective panels
pnlWorking.Controls.Remove(pane1);
pnlReference.Controls.Remove(pane2);
// Add them to the opposite pane
pnlWorking.Controls.Add(pane2);
pnlReference.Controls.Add(pane1);
Unfortunately, this does not work. When I click the linkbutton, nothing happens. If I then do something to perform another postback the reference and working panels become empty. I assume this has to do with the change not being saved into Viewstate but I don't know how to get around that.
Does anyone have any ideas on how to do this?
Update: It seems that moving objects around with Jquery is causing issues with asp.net postbacks as well as making my asp.net ajax tabcontainer completely fail to function. After 2 swaps and postbacks, further postbacks cease to function at all. Here's the new code
<div id="referencePane">
<asp:panel id="pnlsection1" runat="server" >
Content with tab container
</asp:panel
</div>
Swap Panes
<div id="workingPane">
<asp:panel id="pnlsection2" runat="server" >
Content
</asp:panel>
</div>
Here's the javascript:
function SwapPanes() {
var pane1, pane2;
pane1 = $("#workingPane").html();
pane2 = $("#referencePane").html();
$("#workingPane").empty();
$("#referencePane").empty();
// Add them to the opposite pane
$("#workingPane").prepend(pane2);
$("#referencePane").prepend(pane1);
}
First postback causes the tabcontainer to fail (javascript exceptions claiming it's trying to create a tab container with teh same ID (only one exists in the original aspx page). Postbacks then proceed to do wierd stuff.
Have you thought about keeping the controls in the panel but just swapping the position of the panels? You can do this pretty easily in JQuery although you'll be using DIVS instead of ASP.NET panels. This is, again, quite easy since Panels just translate to DIVS in the end. I did this recently for a wizard-style questionnaire (moving from panels to divs) and I was surprised how easy it was.
Update: Note that, when you swap the div positions, you can change the style as well (again, easy in JQuery) so that the user won't have a jarring "why did these two things change position" experience.
The bottom line, really, is that I think you are trying to use a hammer to drive a screw. JQuery is the screwdriver you are looking for and learning it is very much worth your while!
Look into ASP.Net web parts. That will manage the whole thing for you in a dynamic and responsive way.
I have 3 different kinds of ajax popups that need to exist across my site. I was hoping that I could simply create a user control for each one and place the panel and modal popup extender inside each one but this doesn't seem to be working. Has anyone tried this before or do you have a recommendation as to how I can avoid duplicate code for each pop up on different pages? Thanks!
Ah I figured out my issue with the User Control I believe.
The ModalPopUpExtender requires the TargetID property to be set otherwise an error occurs. Since this is sitting in a UserControl I just created a dummy link button that doesn't do anything and I set the property visible to false.
<asp:LinkButton ID="lnkBlank" runat="server" Visible="false" />
<asp:Panel ID="plContainer" style="display: none;" runat="server">
Hello?
</asp:Panel>
<cc1:ModalPopupExtender ID="mpe" runat="server"
BehaviorID="test"
TargetControlID="lnkBlank"
PopupControlID="plContainer" />
Apparently it doesn't appreciate that and the moment I set the visible property to true it started working. Not sure what the reasoning is for a TargetID since, I would think, most pop ups could be called from multiple links about the page. Perhaps I'm still not entirely clear on how this control is supposed to be used.
One option would be to write the popups in a asp.net user control (a .ascx page) and include that on the pages you need the popups. Have a public method in the ascx page that will show the popup, and call it from the parent page when you need to. If you already have a script manager on the parent page, you can't have a second one in the ascx page, but other then that there shouldn't be anything that would stop this from working. Hope this helps!
edit: here's what my modal popup extender control looks like...
<cc1:ModalPopupExtender
ID="mpeClassroom"
BackgroundCssCLass="modalBackground"
runat="server"
CancelControlID="lbClose"
OnOkScript="onOk()"
TargetControlID="Button1"
PopupControlID="pnlClassroom">
</cc1:ModalPopupExtender>
in my code behind page, my method just calls mpeClassroom.Show();
The problem with hidden link as TrgetControlID is that; when u set its visibility as false, server doesn't render it as well. PopExtender then cannot find control on the page.
Instead of setting its visibility to false, try to apply a style with display:none. This should work !
OK, another road bump in my current project.
I have never had form elements in both my master and content pages, I tend to have all the forms in the content where relevant.
In the current project however, we have a page where they want both. A login form at the top right, and a questions form in the content.
Having tried to get this in, I have run in to the issue of ASP.NET moaning about the need for a single form element in a master page. TBH, I really dont get why this is a requirement on ASP.NET's part, but hey ho.
Does anyone know if/how I can get the master and content pages to contain form elements that work independantly?
If not, can you offer advice on how to proceed to get the desired look/functionality?
Thought I would review some of my outstanding questions and see if I can close some of them off.
This one was an interesting one. I outright refused to believe you can only have one form on an ASP.NET page. This to me made no sense. I have seen plenty of webpages that have more than one form on a web page, why should an ASP.NET page be any different?
So, it got me thinking.
Why does a ASP.NET page need a form element?
ASP.NET pages try to emulate the WinForms environment, by provided state persistance through the PostBack model. This provides an element of state to a stateless environment. In order to do this, the runtime needs to be able to have the ability to maintain this state within each "form". It does this by posting back data to itself. It's important to note that:
There is nothing really fancy about a PostBack.
It uses a HTTP form and POST, the same as any other form, from any other stack.
Just because it looks like it might be doing something special, its not, all that happens is it POST's back with some info about what caused it, so you can do things like handle client-side events, in server-side code.
So why only one?
This to me was the million pound question (I am British). I understand that ASP.NET needs this, especially if you are using ASP.NET server controls, but why the hell can't I make my own additional forms?
So, I thought screw it, just make your own form!
And I did. I added a bog-standard, simple form with a submit action of "#". This then performs a POST to the current page, with the Form data for the given form in the request.
Guess what? It all worked fine. So I ended up with:
A master page, with a HTML form in
This form posts back to the current page (basically the page using the master).
In the Page_Load code-behind for the master, I then added code to check the request to see what data was passed in the request. If it contains data (say a hidden field) then I know the post was sourced from the Form on the master page, if not, then it is most liekly a PostBack from content, and can be ignored.
I then surrounded the Content tags with <form runat="server" id="aspNetForm"...> </form> tags. This meant that all content pages automatically had a form to work with.
This provided me with a relatively simple, clean solution to my problem. My login form works fine in tandem with all the content forms created, some of which are complex forms, others use lots of server controls and many PostBacks, and so on.
I hope this helps others.
the form tag itself is in the MasterPage, as such, you can code any asp.net server controls onto the master page that you wish. And you can write up the processing logic for those server controls on the master page's code behind file.
So, in your example, you can have the login controls on the upper right of the master page, and then have the authentication logic in the code page for the MASTER PAGE, not your content page.
This allows you to have the login controls on every page, and maintain that processing, as well as maintain the content controls and their processing on their individual pages.
Everyone else has already mentioned that you can only have a single form element in a given ASP.NET page, and that it would be contained in the master page. So far, so good. But I don't think that helps you get fully where you want to be ...
In your master pages, you've (I assume!) defined asp:ContentPlaceHolder controls. Your pages which use the master then have corresponding asp:Content tags. All your page content must go in these corresponding asp:Content tags.
Once in that tag, they are part of the master page's form. The master page can respond to events from its own controls, and the pages themselves respond to events from their own controls, and you're set.
If you need the page to interact with the master page, you can access it via the Page.Master property. To interact with any publicly-visible code (methods, properties, etc.) from the master page, you'd cast this property to the correct type, and access the publicly-visible code from there.
That should get you where you need to be in this scenario. (It's worked for me on multiple sites!)
Rob,
Interesting solution. I don't see any problem with what you are doing. The problem some may encounter however, is if they try to do this with 2 server forms. There's no rule in ASP.NET that you can't have more than 1 HTML form on a page, just that you can't have more than one "runat='server'" form on the page. Obviously you've found a pretty easy way of meeting your needs.
I've found that for the most part dealing with a single form is not a problem because the ASP.NET framework basically separates everything for us with naming containers. But in your initial post comment you hit on the important factor that was absent yet critical to the essence of the original question: enter key behavior. That always throws a monkey wrench into the works.
If you were to use a standard "all encompassing" server form, couldn't you capture the right action using a textbox text changed event? Of course, if the user changed both values before hitting enter on either you would get strange behavior. And I think the core problem with the enter key is that once you have more than one submit input on an HTML form, hitting ENTER in a textbox doesn't do anything. Only when there is a single INPUT element does the enter key cause one to be "clicked".
None of the previous answers gave a code example. Here's a simplified version of the Visual Studio 2012 Site.Master that illustrates how to do this:
<%# Master Language="C#" AutoEventWireup="true" CodeBehind="Site - Copy.Master.cs" Inherits="WebApplication1.Site1Master" %>
<!DOCTYPE html>
<html>
<head runat="server">
<title>This is a title</title>
<asp:ContentPlaceHolder runat="server" ID="HeadContent" />
</head>
<body>
<form runat="server">
<header>
<div class="content-wrapper">
<div class="float-right">
<section id="login">
<asp:LoginView runat="server" ViewStateMode="Disabled">
<AnonymousTemplate>
<asp:ContentPlaceHolder runat="server" ID="AnonContent" />
</AnonymousTemplate>
<LoggedInTemplate>
<asp:ContentPlaceHolder runat="server" ID="LoggedInContent" />
</LoggedInTemplate>
</asp:LoginView>
</section>
</div>
</div>
</header>
<div id="body">
<asp:ContentPlaceHolder runat="server" ID="FeaturedContent" />
<section class="content-wrapper main-content clear-fix">
<asp:ContentPlaceHolder runat="server" ID="MainContent" />
</section>
</div>
</form>
</body>
</html>
So you have everything wrapped by a single Form element, so you can place controls in the master page, yet your content pages can also use controls.
You can only have one form on an ASP.NET page. One way to handle this is to put an event handler on the login button in the master page. The handler will validate the user and redirect to the same page on success (to correctly run the Page_Load handler, which is run before event handlers).
I solved the "clicking the return key in the login sub-form causes the main form to submit" problem in my current project by embedding an iframe into the master page. The iframe pointed to the login.aspx page which authenticated the user.
<iframe id="login" src="login.aspx" frameborder="0" enableviewstate="false" scrolling="no" runat="server"></iframe>
(form some reason I needed the closing /iframe tag otherwise design view got confused)
You can access MasterPage controls from the aspx form by:
add the detractive tag to the aspx form <%# MasterType VirtualPath="~/Site.Master %>
and in the code behind use Master.FindControl(); to get the control by ID
for Example if you want to get the
Control form = Master.FindControl("form")
now you can use the master page's form in your code.
I hope this help.
Salve! In a similar thread, I posted an answer that might help you. You can use jquery to add content to an empty div. That content can include form tags, and even a submit function independant of anything the server-side code is doing. The only downside to this is if the user does not have javascript enabled!
Instead of reposting the same answer (and the code too), here is the link:
Jquery Ajax loading form on asp.net webform
This is a limitation of ASP.NET
ASP.NET is designed to have one form per page and only one form. When it was originally designed that was not a problem.
However since then this has been identified as a huge problem with accessibility.
Microsoft Fix for this was ASP.NET MVC, if you are able to I would suggest considering moving to ASP.NET MVC as it solves a large number of problems with ASP.NET
You can have more than 1 form. (just only 1 visiable at a time) codeline 1 = form 1 visable / form 2 hidden . Code 2 Form 2 visable / form 1 hidden. = solved (this is great for static contact forms as well
no, you can only have one asp.net form per page.
That has been the rule since 1.0
They should both share the same form
I have a gridview that is within an updatepanel for a modal popup I have on a page.
The issue is that the entire page refreshes every time I click an imagebutton that is within my gridview. This causes my entire page to load and since I have grayed out the rest of the page so that the user cannot click on it this is very annoying.
Does any one know what I am missing.
Edit: I entered a better solution at the bottom
Make sure you have the following set on the UpdatePanel:
ChildrenAsTriggers=false and UpdateMode=Conditional
do you have ChildrenAsTriggers="false" on the UpdatePanel?
Are there any javascript errors on the page?
I had this problem and came across the following article:
http://bloggingabout.net/blogs/rick/archive/2008/04/02/linkbutton-inside-updatepanel-results-in-full-postback-updatepanel-not-triggered.aspx
My button wasn't dynamically created in the code like in this example, but when I checked the code in the aspx sure enough it was missing an ID property. On adding the ID the postback became asynchronous and started to behave as expected.
So, in summary, check your button has an ID!
Are you testing in Firefox or IE? We have a similar issue where the entire page refreshes in Firefox (but not IE). To get around it we use a hidden asp:button with the useSubmitBehavior="false" set.
<asp:Button ID="btnRefresh" runat="server" OnClick="btnRefresh_Click" Style="display: none" UseSubmitBehavior="false" />
Several months later this problem was fixed. The project I was working in was a previous v1.1 which was converted with 2.0. However, in the web.config this line remained:
<xhtmlConformance mode="Legacy"/>
When it was commented out all of the bugs that we seemed to have with the ajax control toolkit disappeared
Is the Modal Window popped up using the IE Modal window? Or is it a DIV that you are showing?
If it is an IE Modal Pop up you need to ensure you have
<base target="_self" />
To make sure the post back are to the modal page.
If it is a DIV make sure you have your XHTML correct or it might not know what to update.
I would leave the onClick and set it as the trigger for the updatePanel.
That's odd that it works in FF and not IE. That is opposite from the behavior we experience.
UpdatePanels can be sensitive to malformed HTML. Do a View Source from your browser and run it through something like the W3C validator to look for anything weird (unclosed div or table being the usual suspects)
If you use Firefox, there's a HTML validator Extension/AddOn available that works quite nicely.
For reference..
I've also noticed, when using the dreaded <asp:UpdatePanel ... /> and <asp:LinkButton ... />, that as well as UpdateMode="Conditional" on the UpdatePanel the following other changes are required:
ViewStateMode="Enabled" is required on <asp:Content ... /> (I've set it to Disabled in the MasterPage)
ClientIDMode="Static" had to be removed from <%# Page ... />
To prevent post-backs add return false to the onclick event.
button.attribute.add("onclick","return false;");
Sample:
string PopupURL = Common.GetAppPopupPath() + "Popups/StockChart.aspx?s=" + symbol;
hlLargeChart.Attributes.Add("onclick", String.Format("ShowPopupStdControls(PCStockChartWindow,'{0}');return false;", PopupURL));