动态创建的单选按钮不显示选中的ASP.NET

Question

I'm writing a WebApplication that has a list of RadioButton controls, dynamically generated based on information from a database. My problem is, the RadioButton that I "check" is not displaying as being checked.

HTML:

<asp:CustomValidator ID="vgCheckRequiredChoice" Display="Static" runat="server" ValidationGroup="vgTicketTypeChoice"
    Text="You must select an office location to continue." ForeColor="Red"></asp:CustomValidator>
<table style="padding: 10px 10px 10px 10px; width: 100%" cellpadding="5px 5px 5px 5px">
    <asp:Repeater ID="rptType" runat="server" OnItemDataBound="rptType_ItemDataBound">
        <ItemTemplate>
            <tr style="border-bottom: solid 1px #000000; padding: 40px 10px 10px 10px;">
                <td style="width: 30%;">
                    <asp:RadioButton runat="server" ID="RadioButtonLocation" Text='<%# Bind("LocationName") %>' 
                    GroupName='<%# Bind("LocationID") %>' ValidationGroup="vgTicketTypeChoice"
                    CausesValidation="true" />
                </td>
            </tr>
        </ItemTemplate>
    </asp:Repeater>
</table>
<div style="float: right; display: inline; padding-right: 20px; padding-top: 20px;">
    <asp:Button runat="server" ID="ButtonCancel" Text="Cancel" PostBackUrl="~/Default.aspx" />
    <asp:Button runat="server" ID="ButtonDefiningLocation" Text="Next >>"OnClick="ButtonDefiningLocation_Click" />
</div>

Here is the JavaScript that I'm using to check each unique RadioButton:

 <script type="text/javascript">
    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;
    }
</script>

Last but not least the CodeBehind:

protected void rptType_ItemDataBound(object sender, RepeaterItemEventArgs e)
    {
        if (e.Item.ItemType != ListItemType.Item && e.Item.ItemType != ListItemType.AlternatingItem)
            return;
        RadioButton rdo = (RadioButton)e.Item.FindControl("RadioButtonLocation");
        string script =
           "SetUniqueRadioButton('rptType.*VisitingOffice',this)";
        rdo.Attributes.Add("onclick", script);
    }

    protected void ButtonDefiningLocation_Click(object sender, EventArgs e)
    {
        rptType.DataBind();
        if (Page.IsValid)
        {
            foreach (RepeaterItem ri in rptType.Items)
            {
                switch (ri.ItemType)
                {
                    case ListItemType.Item:
                    case ListItemType.AlternatingItem:
                        RadioButton rb = (RadioButton)ri.FindControl("RadioButtonLocation");
                        if (rb.Checked)
                        {
                            var LocationID = rb.GroupName;
                            DataService ds = new DataService();
                            DataTable tbl = ds.GetLocation(LocationID);
                            Response.Write(LocationID);

                        }
                        break;
                }
            }
        }
    }

As you can see, in the codebehind, when I stepthrough the program and get down to "rb.checked" it will display the correct options for rb (Example: {Text="Houston" Checked= false} even if Houston is the selected RadioButton.)

Answer 1

In case anyone else has the same problem, I figured out where my mistake was. In the Page_Load I had forgotten to set the DataSource and the DataBind for the repeater in the if "is not PostBack" section. PageLoad should look like this.

protected void Page_Load(object sender, EventArgs e)
    {
        var FormattingPlaceHolder = Master.FindControl("BottomLinkButtonDiv");
        FormattingPlaceHolder.Visible = false;
        if(!IsPostBack)
        {
        var ds = new DataService();
        rptType.DataSource = ds.GetLocationIDs();
        rptType.DataBind();
        }
    }

Thanks everyone for their suggestions. Happy coding.

Answer 2

My guess is that the call to databind in the click event is resetting the values. If I need to call databind explicitly I do it after control changed events eg In LoadComplete http://msdn.microsoft.com/en-us/library/ms178472(v=vs.100).aspx I used to have this problem quite a lot but I'm wise to it now (touch wood).