radio button list in repeater control

Question

I have a repeater control in my page. I need to have a radio button in all the rows(Item template) on checking an radio button the remaining radio buttons must unchecked.

How to do this?

Thanks in advance, Tor

Answer 1

Unfortunately, it's a known bug ( http://support.microsoft.com/kb/316495 ) that the GroupName property doesn't work as expected when used in a Repeater. The problem is that the Repeater implements the INamingContainer interface which requires all nested controls to have a unique name when rendered out to HTML. This causes the radio buttons to break because in order for them to work properly they must have identical names.

There are 2 work-arounds that I've come across:

1 - The first is a client-side javascript solution. It was provided by Microsoft support. Or an easier to read version here. The instructions are as follows. Include the following javascript in the HEAD:

function SetUniqueRadioButton(nameregex, current)
{
      re = new RegExp(nameregex);
      for(i = 0; i < document.forms[0].elements.length; i++)
      {
            elm = document.forms[0].elements[i]
            if (elm.type == 'radio')
            {
                  if (re.test(elm.name))
                  {
                          elm.checked = false;
                  }
             }
      }
      current.checked = true;
}

Now the function needs to be linked to the Radio Buttons in the OnDataItemBound event of the repeater. Replace "RadioButton" with the name of your RadioButton control and "RadioGroup" with the GroupName you have chosen:

protected void Repeater1_ItemDataBound(object sender, RepeaterItemEventArgs e)
{
      if (e.Item.ItemType != ListItemType.Item && e.Item.ItemType != ListItemType.AlternatingItem) return;
      RadioButton rb = (RadioButton) e.Item.FindControl("RadioButton");
      string script = "SetUniqueRadioButton('Repeater1.*RadioGroup',this)";
      rb.Attributes.Add("onclick", script);
}

2 - The second solution is a server-side solution using a custom usercontrol that inherits from RadioButton. The tutorial and source code can be downloaded here: http://www.codeproject.com/KB/webforms/How_group_RButtons.aspx