I'm working in ASP.NET and I have a CheckBoxList where I want one of the options to be basically like "Other: _." So I need to include a textbox where the user can fill in their own option. It doesn't seem like there's a way to include a textbox inside of a checkboxlist, however. What's the best way to make this work?
-UPDATE-
If using a separate textbox control, how do I position it so it will align correctly with the checkbox?
Make the textbox a separate control on the page, then in your codebehind, check to see if other is checked. If it is, pull the value of the textbox, and use that.
To answer the question in your edit: You'll have to play with the CSS of the page to get it positioned correctly. How you do it depends on the layout of the page, among other things. I recommend posting some of the HTML from your page in another question and ask about how to position them.
What #Kyle Trauberman said...
Make the textbox a separate control on
the page, then in your codebehind,
check to see if other is checked. If
it is, pull the value of the textbox,
and use that.
Plus use javascript to hide or gray out the option unless the checkbox is selected.
string test="";
<asp:CheckBoxList ID="chk_list" runat="server">
<asp:ListItem Value="00">xxxx</asp:ListItem>
</asp:CheckBoxList>
<asp:TextBox ID="other" runat="server"></asp:TextBox>
inside the for loop
if (chk_list.Items[i].Value == "00")
{
test +=chk_list.Items[i].Text + other.Text;
}
Is it possible to set a specific ID on an ASP.NET server control? Everytime I assign an ID and run the web form the ID changes.
For Example:
<asp:TextBox ID="txtName" runat="server"></asp:TextBox>
Gets translated into this:
<input id="ct100_ContentPlaceHolder1_txtName" type="text" />
I think this is do to me using master pages, but if so how can I be sure a control will have a certain ID(for javascript purposes). I placed the auto-generated id in my javascript and it is working, but I would prefer to have used the id's that I originally assigned them. Is this possible?
(This is for version:ASP.NET 3.5)
Starting with .NET 4 you have greater control about how the client-side IDs look like (see this post for details).
To force a specific client-side ID, you have to set the ClientIDMode to static. The following will render an <input> element with id="txtName":
<asp:TextBox ID="txtName" ClientIDMode="static" runat="server"></asp:TextBox>
Although if you do this, you have to ensure that you don't have two controls with identical client-side IDs. Check the article linked above for other options.
This is the way web controls ID's are in .NET prior to version 4.0. Version 4.0 introduces client IDs, which you can read about here.
You can use somthing like this in your JS:
var something = '<%= txtName.ClientID %>';
You can use the Control.ClientID property in your codebehind to get the actual id after it's been added to the control tree.
Super annoying choice made by the asp.net webforms people.
I use ASP.NET and have a label control on my page, which I fill with
the jQuery-Command
$('#<%= myLabel.ClientID %>').html(content);
.val() does not seem to work with this.
Somehow, I have Problems getting the content in code-behind. In the code, the myLabel.Text-Property is still empty.
If you want to display the value on the client and have it available on the page, you need an input that'll get sent to the code-behind when you POST like this:
$('#<%= myLabel.ClientID %>').html(content);
$('#<%= myInput.ClientID %>').val(content);
<asp:Label Id="myLabel" runat="server" />
<asp:HiddenField ID="myInput" runat="server" />
In the code-behind:
myInput.Value
I think your problem is that labels (rendered as span tags) are inherently read-only in the asp.net world. They're not meant to be used as 'input' controls, and as such changes to their HTML on the client-side are ignored on the server-side, where values are set based on ViewState.
To do what you are asking, you'd have to notify the server of the change as well, such as by using AJAX. The only issue here is ajax webmethods in your code behind are static, and because of this can't access the page's control set to change the .Text value.
In the end the easiest option is to make use of hidden fields as Nick said. These are technically 'input' controls and their values changed on the client-side are sent to the server as you desire. You'd just have to keep the label/span and hidden field/input synchronized on the client.
Hope this helps.
It seems everyone is doing this (in code posts etc.)...but I don't know how. :(
Whenever I try to manipulate an asp element using JavaScript I get an "element is null" or "document is undefined" etc. error.....
JavaScript works fine usually,...but only when I add the runat="server" attribute does the element seem invisible to my JavaScript.
Any suggestions would be appreciated.
Thanks, Andrew
What's probably happening is that your element/control is within one or more ASP.NET controls which act as naming containers (Master page, ITemplate, Wizard, etc), and that's causing its ID to change.
You can use "view source" in your browser to confirm that's what's happening in the rendered HTML.
If your JavaScript is in the ASPX page, the easiest way to temporarily work around that is to use the element's ClientID property. For example, if you had a control named TextBox1 that you wanted to reference via JS:
var textbox = document.getElementById('<%= TextBox1.ClientID %>');
Making an element runat="server" changes the client-side ID of that element based on what ASP.NET naming containers it's inside of. So if you're using document.getElementById to manipulate the element, you'll need to pass it the new ID generated by .NET. Look into the ClientId property to get that generated ID...you can use it inline in your Javascript like so:
var element = document.getElementById('<%=myControl.ClientID%>');
If you have a textbox:
<asp:TextBox id="txtText" runat="server" />
YOu can use:
var textBox=document.getElementById('<%=txtText.ClientID %>');
Any WebControl exposes the same ClientID property.
All though the question has been answered, thought I would just post some further info...
Rick Strahl provided quite an intresting work around to this problem.
http://www.west-wind.com/WebLog/posts/252178.aspx
Thankfully when ASP .NET 4.0 arrives, it will allow you to specify exacly what the client ID's will be!
http://www.codeproject.com/KB/aspnet/ASP_NET4_0ClientIDFeature.aspx
I have this label control in my web page
<asp:Label ID="Label1" runat="server" Text="test"></asp:Label>
And when the page rendered the id of the control changes to something like this
<span id="ctl00_ContentPlaceHolder1_Label3">test</span>
How can I stop asp.net from changing IDs in order to perform a jQuery operation like this
$('#label1').html(xml);
Short answer:
Set ClientIDMode="Static"
<asp:Label ID="myLabel" ClientIDMode="Static" runat="server" Text="testing"></asp:Label>
Long answer:
.NET 4 now has the ability to let you choose your ClientIDMode:
Type: System.Web.UI.ClientIDMode
A value that indicates how the ClientID property is generated.
AutoID
The ClientID value is generated by concatenating the ID values
of each parent naming container with the ID value of the control. In
data-binding scenarios where multiple instances of a control are
rendered, an incrementing value is inserted in front of the control's
ID value. Each segment is separated by an underscore character (_).
This algorithm was used in versions of ASP.NET earlier than ASP.NET 4.
Static The ClientID value is set to the value of the ID property. If
the control is a naming container, the control is used as the top of
the hierarchy of naming containers for any controls that it contains.
Predictable This algorithm is used for controls that are in data-bound
controls. The ClientID value is generated by concatenating the
ClientID value of the parent naming container with the ID value of the
control. If the control is a data-bound control that generates
multiple rows, the value of the data field specified in the
ClientIDRowSuffix property is added at the end. For the GridView
control, multiple data fields can be specified. If the
ClientIDRowSuffix property is blank, a sequential number is added at
the end instead of a data-field value. This number begins at zero and
is incremented by 1 for each row. Each segment is separated by an
underscore character (_).
Inherit The control inherits the ClientIDMode setting of its NamingContainer control. This is the default.
instead of using this selector
$('#Label1')
use this one, basically you are using the classic asp inline server side code.
$('#<%= Label1.ClientID %>')
this will insert whatever ID that is generated to be placed as a literal.
If you wish to use external files then I would suggest you create an obj that is global on the page to hold all of your client ids and then reference that obj within your external files (not ideal but it is a solution)
var MyClientIDs = {
Label1 = '<%= Label1.ClientID %>',
Label2 = '<%= Label2.ClientID %>',
Textbox1 = '<%= Textbox1.ClientID %>',
Textbox2 = '<%= Textbox2.ClientID %>'
};
and then in your external file you can access Label1 for example: $('#' + MyClientIDs.Label1)
In .NET 4+ set ClientIDMode="Static". This will solve your problem.
Example:
<asp:Label ID="Label1" ClientIDMode="Static" runat="server" Text="test"></asp:Label>
You can't stop asp.net from generating those IDs. That's just how it does things.
You can still use jquery like so:
$('#<%=label1.ClientID %>').html(xml)
or
$('[id$=_label1]').html(xml)
If and only if you're container layout is never going to change and you require to put your JavaSctipt/jQuery in an external file, you could use the generated ids within your jQuery selectors i.e.
$('#ctl00_ContentPlaceHolder1_Label3').html(xml);
Obviously, this approach requires you to find out what the generated ids will be and requires caution if you ever start changing the site/application construction.
Otherwise, your best options are
1. Use the inline server side code markup. The downside to this approach is that you cannot put your js code in an external file -
$('#<%= Label3.ClientID %>').html(xml);
2. Define unique CSS classes on each control you need to use in your jQuery, which would still allow you to put your js code in an external file -
<asp:Label ID="Label3" runat="server" Text="test" CssClass="label3">
</asp:Label>
$('.label3').html(xml);
3. Use jQuery selectors to pattern match the original id, which again, would allow you to put your js code in an external file -
$('[id$=Label3]').html(xml);
This jQuery selector will select all elements with attribute id whose value ends with Label3. The only potential downside that I could see with this approach is that in theory, it could be possible to have a Label control with id Label3 in say, a Master page and also in two content pages. In this example, using the jQuery selector above would match all three labels, which may have unwanted consequences.
EDIT:
I thought it might be useful to raise your attention to the IDOverride control. An Example page can be found here
It allows you to specify which controls should have their mangled id within the outputted HTML markup overridden with the id as is given in the .aspx file when rendering out the HTML page. I have only played with it briefly with a single Master Page and Panels, but it appears to work well. Using this, you could use the original ids within your jQuery selectors. Be aware however, that the results are unpredictable if you were to have controls with the same ids in your Master page(s) and Content page(s) that are combined to render the HTML for one page.
Short answer, don't worry about using the asp.net IDs. In asp.net you can add your own attribute to a tag:
<asp:TexBox ID="myTBox" runat="server" MyCustomAttr="foo" />
Then in jquery you can refer to this element via:
$("input[MyCustomAttr='foo']")
I do this all the time with jQuery. Hope it helps.
You can call a class name rather than using an ID
For example;
$('.CssClassName'). ...
Or if you type this in the MasterPage's very first line, your control IDs won't change :
ClientIDMode="Static"
For example;
<%# Master Language="C#" AutoEventWireup="true" CodeFile="MasterPage.master.cs" Inherits="Main_MasterPage" ClientIDMode="Static" %>
The inline code is the correct way to do it. However this will be changing in ASP.NET 4.0. We have spent some time adding a feature that allows full control of the IDs that are generated client side. Below are some resources on the web about this feature.
http://blog.osbornm.com/archive/2009/01/06/asp.net-4.0-clientid-overview-again.aspx
http://channel9.msdn.com/shows/10-4/10-4-Episode-3-ASPNET-WebForms-40/
Most of the suggestions here will work, but test results on jQuery code show that pure ID selectors are by far the fastest. The one I use most often:
$("[id$=origControlId]")
is pretty slow, but the problem isn't too apparent unless the page has many controls and a lot of jQuery.
Since is it fairly painless to assign multiple classes to a control, you could give each one a CSSClass that matches the ID. Since they would then be unique (you'll have to watch repeater type controls that generate multiple controls), you could select by class.
For example:
<asp:Label ID="Label1" CssClass="Label1 SomeOtherClass" runat="server" Text="test">
</asp:Label>
could be selected uniquely by:
$(".Label1")
Which is almost as fast as an ID select.
I had never considered this one:
$('#<%= Label1.ClientID %>')
but I'm going to try it!
You have to pass the control's ClientID to the javascript code (I doubt though that Label1 gets renamed to Label3)
ClientScriptManager.RegisterClientScriptBlock(GetType(), "someKey",
"$('#" + Label1.ClientID + "').html(xml);", true);
You can use the ClientID (just like everyone else said) but the problem with that is that it cannot be used in an external JavaScript File.
So, ideally, instead of using the ID to reference it from jQuery, use a CSS class:
<asp:Label ID="Label1" runat="server" Text="test" CssClass="myclass"></asp:Label>
Then you can reference it like such:
$(".myclass")
You can override the ClientID and the UniqueID as this fella did.
/// <summary>
/// Override to force simple IDs all around
/// </summary>
public override string UniqueID
{
get
{
return this.ID;
}
}
/// <summary>
/// Override to force simple IDs all around
/// </summary>
public override string ClientID
{
get
{
return this.ID;
}
}
You may also create a custom control that inherits from Label that overrides the ID property to be what you want it to be.
This can be achieved by replacing the asp.net id with the original id as the control is rendered.
This is pretty easy and can be donw by creating a set of custom controls.
http://www.bytechaser.com/en/articles/ts8t6k5psp/how-to-display-aspnet-controls-with-clean-id-value.aspx
At the risk of being patently obvious change:
<asp:Label ID="Label1" runat="server" Text="test"></asp:Label>
to
<Label ID="Label1" Text="test"></Label>
You need to put the property ClientIDMode="Static" in your button, this grants the ID will be the same in runtime, it's what you need to get object in Javascript.
you don't need to "prevent" asp.net from changing the control id in order to use jquery, or javascript at all for that matter.
the id that gets rendered on your page is the ClientID property of the control and what you're setting on the control itself is the ID. you can't set the ClientID property, it's generated for you and may or may not be the same as your ID. however, as others have mentioned you can use the ClientID property either in your aspx:
$('<%= Label1.ClientID %>').html()
or by registering the client script in your code behind file using one of the ClientScriptManager methods.
Just get rid of the placeholder. Or select by class or DOM hierarchy. Or even use partial matching on the ID as a last resort. There are many easy, clean ways to select an element in jQuery, we need to wean ourselves away from our old, ugly ASP.NET habits.
And Dreas Grech put the final nail in the coffin. You can't use use external script files with the $('#<%=label1.ClientID %>') type solutions.
Mike
You still can use PlaceHolders and set ClientIDMode in the PlaceHolder tag :
<asp:ContentPlaceHolder ID="BodyContent" runat="server" ClientIDMode="Static">
</asp:ContentPlaceHolder>
None of the contained controls IDs will be altered.
Simple, with overriding the control class. Here is an example with an HtmlGenericControl but you can do it with any ASP.Net control:
public class NoNamingContainerControl : HtmlGenericControl
{
public NoNamingContainerControl(string tag) : base(tag) { }
public override string ClientID
{
get
{
return this.ID;
}
}
}