asp:RadioButtonList doesn't set correct selected item on load

Question

I have this code:

<asp:RadioButtonList ID="rblExpDate" runat="server" >
    <asp:ListItem Selected="True" Text="No expiration date"></asp:ListItem>
    <asp:ListItem Text="Expires on:"></asp:ListItem>
</asp:RadioButtonList>

that I would like to be always, on page load, to mark the first option ("no expiration date"). However, if the user marks the second option and reloads, the second option is selected, even though I do this on page load:

rblExpDate.Items[0].Selected = true;
rblExpDate.SelectedIndex = 0;

Appreciate your help!

Answer 1

Are you sure that your code is not within a postback check?

        if (!Page.IsPostBack)
        {
            rblExpDate.Items[0].Selected = true;
            rblExpDate.SelectedIndex = 0;
        }

More to the point, this sounds like a strange requirement that doesn't sound very useable. Why have an option available if you are always going to override it?

Answer 2

What most probably happens is that the code executed on Page_Load runs first, setting the element you want. After that the SelectedIndexChanged event of the RadioButtonList fires and gets the selected item from the ViewState, overriding what the code did. You have to debug this, though.

Answer 3

The solution I chose is in Javascript (mootools):

window.addEvent('domready', function() {
         $("rblExpDate_0").checked = true;
});

(I gave up on the .net side)

thanks for your help @Slavo and @Daniel Dyson.