asked on

reference a control that has been dynamically created

I have a web project created with vs2008 and .net 3.5. I have created a radiobuttonlist control in a table cell dynamically by adding the control to the tablecell.controls collection. The problem is that I can't retrieve this control from code behind on a button click, the tablecell.controls collection returns 0 as the count.

How can I do this? I need to read the radiobuttonlist selection to perform an action.

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kaufmed

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Miguel Oz

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Dmitry G

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james henderson

ASKER

Sorry, all, seems I didn't provide enough information. This is a content page that is using a master page. I have a function called loadPage() that is called from a button click. The control is defined in an xml file, along with the options:
<control name="OptionList" type="radio">
<options>
<option text="Option1" code="OPT1" />
<option text="Option2" code="OPT2" />
<option text="Option3" code="OPT3" />
<option text="Option4" code="OPT4" />
<option text="Option5" code="OPT5" />
</options>
</control>

Here is the code that write the control on the page:
switch (controlType.Value)
{
case "radio":
rl = new RadioButtonList();
rl.ID = controlName.Value;

rl.SelectedIndexChanged += new EventHandler(rlb_SelectedIndexChanged);

var options = item.XPathSelectElement("options");

foreach (XElement opt in options.Elements())
rl.Items.Add(new ListItem(opt.Attribute("text").Value, opt.Attribute("code").Value));

tr = TableSurvey.Rows[2];
tc = tr.Cells[0];
tc.Text = "Please select an option";

tc = tr.Cells[2];
tc.Controls.Add(rl);
break;
}

This displays the control perfectly and the control works as expected, but no event fires and I don't know how to reference the control correctly to try to read it's selection.

I really appreciate you all taking a stab at this.

james henderson

ASKER

Forgot to add the event code:
private void rlb_SelectedIndexChanged(object sender, EventArgs e)
{
sOption = ((RadioButtonList) sender).SelectedValue;
}

sOption is a class level string.

SOLUTION

Miguel Oz

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james henderson

ASKER

here is the code behind for the page. it's only for a single page, so there's nothing missing.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Xml; //namespace to deal with XML documents
using System.Xml.Linq; //namespace to deal with LINQ to XML classes
using System.Xml.XPath;
using System.Xml.Serialization;
using System.IO;
using TMSSI.BipiDTC;
using System.Web.UI.HtmlControls;

namespace TMSSI.BipiDTC.Pradaxa.Branded
{
public partial class branded : System.Web.UI.Page
{
private static string pageName = null;
private string xmlTranslations = HttpContext.Current.ApplicationInstance.Server.MapPath("~/Translations.xml");
private string xmlPages = HttpContext.Current.ApplicationInstance.Server.MapPath("~/WebPageDefinitions.xml");
RadioButtonList rl = null;
private string sOption = null;

protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
pageName = "script";
loadPage();
}

}

protected void Button2_Click(object sender, EventArgs e)
{
fetchNextPage();
}

protected void Button1_Click(object sender, EventArgs e)
{

}

private void fetchNextPage()
{
switch (pageName)
{
case "script":
System.Diagnostics.Debug.WriteLine("Option: " + sOption);
break;

}

}

private void fetchLastPage()
{

}

private void loadPage()
{
XElement xml = XElement.Load(xmlPages);
foreach (XElement child in xml.Elements())
System.Diagnostics.Debug.WriteLine(child);

TableRow tr = null;
TableCell tc = null;

string val = "/webPage[@name='" + pageName + "']";

var pages = xml.XPathSelectElements(val);
foreach (XElement item in pages.Elements())
{
System.Diagnostics.Debug.WriteLine(item.Name.ToString());

switch (item.Name.ToString())
{
case "formTitle":
XAttribute title = item.Attribute("title");

tr = TableSurvey.Rows[0];
tc = tr.Cells[0];
tc.Text = title.Value;

break;

case "narration":
XAttribute loc = item.Attribute("location");
System.Diagnostics.Debug.WriteLine(loc.Value);
loc.Value += "/eng";

XElement trx = XElement.Load(xmlTranslations);
var xlat = trx.XPathSelectElement(loc.Value);

tr = TableNarration.Rows[0];
tc = tr.Cells[0];
tc.Text = xlat.Value;

break;

case "control":
XAttribute controlType = item.Attribute("type");
XAttribute controlName = item.Attribute("name");

switch (controlType.Value)
{
case "radio":
rl = new RadioButtonList();
rl.ID = controlName.Value;

rl.SelectedIndexChanged += new EventHandler(rlb_SelectedIndexChanged);

var options = item.XPathSelectElement("options");

foreach (XElement opt in options.Elements())
rl.Items.Add(new ListItem(opt.Attribute("text").Value, opt.Attribute("code").Value));

tr = TableSurvey.Rows[2];
tc = tr.Cells[0];
tc.Text = "Please select an option";

tc = tr.Cells[2];
tc.Controls.Add(rl);
//form1.Controls.Add(rl);
break;
}

break;

}

}

}

private void processPage()
{

}

private void rlb_SelectedIndexChanged(object sender, EventArgs e)
{
sOption = ((RadioButtonList) sender).SelectedValue;

}

}
}

james henderson

ASKER

figured it out. needed to put the code that draws the control in the page_load method.

thanks to all of you for your help.