Comments on: ASP.Net CheckBoxes should be able to have values

By: Jason

Jason — Wed, 01 Apr 2009 17:04:57 +0000

I took what Ryan and WUZ provided and created a server control. This will appear in the toolbox. I had to convert it to VB for this web application.

Option Strict On
Option Explicit On

Imports System
Imports System.Collections.Generic
Imports System.ComponentModel
Imports System.Text
Imports System.Web
Imports System.Web.UI
Imports System.Web.UI.WebControls

Namespace UI.WebControls
     _
    Public Class CheckBoxWithValue
        Inherits System.Web.UI.WebControls.CheckBox

         Property Value() As String
            Get
                Dim s As String = CStr(ViewState("Value"))
                If s Is Nothing Then
                    Return String.Empty
                Else
                    Return s
                End If
            End Get
            Set(ByVal value As String)
                ViewState("Value") = value
            End Set
        End Property

        Protected Overrides Sub OnPreRender(ByVal e As System.EventArgs)
            MyBase.OnPreRender(e)
            Me.InputAttributes("Value") = Me.Value
        End Sub

        Protected Overrides Sub RenderContents(ByVal writer As HtmlTextWriter)
            writer.Write(Text)
        End Sub

    End Class
End Namespace

By: Andrew

Andrew — Wed, 08 Oct 2008 14:58:25 +0000

Sorry, it stripped out my asp code:

asp:CheckBox runat=”server” value=”04″ id=”control”

By: Andrew

Andrew — Wed, 08 Oct 2008 14:12:27 +0000

I found an almost decent way of doing this:

Declare your checkbox:

Then you can programatically add any values by looping through your controls, looking for checkboxes, and doing this:

Control.InputAttributes.Add(“value”, Control.Attributes(“value”))

It will complain that value is not a valid attribute on the asp:checkbox tag, but it works.

By: Chris

Chris — Fri, 03 Oct 2008 08:55:10 +0000

I managed to sort this out by using the CheckedChanged event handler. All you need to do is programmatically change the checked value, then you can reference the checkbox.checked value directly because it fires before the page load event like so....

protected void yourcheckbox_CheckedChanged(object sender, EventArgs e)
    {
        if (yourcheckbox.Checked == true)
        {
            yourcheckbox.Checked = false;
        }
        else
        {
            yourcheckbox.Checked = true;
        }
    }

Hope this helps. :-)

By: wuz

wuz — Sun, 21 Sep 2008 14:39:15 +0000

I think Ryan's custom class is the way to go, and as heared 100 times before we can just use InputAttributes to render the property to html:

public class CheckBoxWithValue : CheckBox
{
public string Value
{
get { return ViewState["Value"] as string; }
set { ViewState["Value"] = value; }
}

protected override void OnPreRender(EventArgs e)
        {
            base.OnPreRender(e);
            this.InputAttributes["value"] = this.Value;
        }
}

By: Nigel

Nigel — Tue, 05 Aug 2008 15:43:48 +0000

There is a similar problem with the name attribute. I’d like to render checkbox controls for use with client side scripts.

Although ChkBox.InputAttributes["name"] = “customName”; does add the name attribute to the HTML page. ASP makes this usless as it also puts in it’s duplicate name attribute.

By: David J Bunge

David J Bunge — Mon, 30 Jun 2008 16:49:54 +0000

The “Value” attribute shows in my browser.
In my ASPX page:

Rendered HTML:
Family

So, the value shows in HTML for me. I’m using ASP.Net 2.0, and I do get the Validation Warning on Visual Studio. However, I’m ignoring it, as the attribute is rendered. Just wanted to share.

By: Tim Phelps

Tim Phelps — Fri, 13 Jun 2008 17:39:03 +0000

Here’s the solution:

Use the InputAttributes property rather than the Attributes property of the CheckBox class.

cb.InputAttributes["value"] = “foo”;

Works like a charm.

Found this on Dave Parslow’s blog:

http://www.daveparslow.com/2007/08/assigning-value-to-aspnet-checkbox.html

By: Michael Bielski

Michael Bielski — Wed, 11 Jun 2008 21:22:02 +0000

Ryan, your custom class doesn’t work. The value attribute is STILL not rendered in the final HTML on the page. It may be in the viewstate, but the tag doesn’t have it. If I ever find a solution, I’ll post it.

By: Ryan Tremaine

Ryan Tremaine — Mon, 07 Apr 2008 00:36:34 +0000

I agree they should have included it. Easy to get around however:

public class CheckBoxWithValue : CheckBox
    {
        public string Value
        {
            get { return ViewState["Value"] as string; }
            set { ViewState["Value"] = value; }
        }
    }