asp:repeater show count of items in each category

Question

I have a simple repeater that gets the 'groups' of 'widgets' The home page lists all of the groups:

<ItemTemplate>
    <tr>
        <td width="60" class="center"><%# DataBinder.Eval(Container.DataItem, "Number") %></td>
        <td><a href="Stories.aspx?ProjectID=<%# DataBinder.Eval(Container.DataItem, "ProjectId") %>"><%# DataBinder.Eval(Container.DataItem, "Name") %></a></td>
        <td><%# DataBinder.Eval(Container.DataItem, "Description") %></td>
    </tr>
</ItemTemplate>

Code Behind

private void LoadForm()
{
    using (MarketingWebContentEntities context = new MarketingWebContentEntities())
    {
        rptGroup.DataSource = (from groups in context.URLGroup
                               select groups).ToList();
        rptGroup.DataBind();
    }
}

I would like within the repeater to show number of 'widgets' within each 'group'. I know I'd need to run a query on the 'widgets' table to see how many items are in that list. I'm just unsure how to add that within the repeater mark-up.

Answer 1

As mentioned in the comment, you could use the ItemDataBound event for this.

This example is in VB - been a while since I wrote C#, though will give you an idea. I haven't checked it for syntax either, it's more an example to get you up and running.

In your <ItemTemplate> add yourself, say, a ASP:Label. In this case, it's called myLabel

So in your code behind, create a private method that will handle the ItemDataBound event.

Protected Sub myRepeater_ItemDataBound(sender As Object, e As System.Web.UI.WebControls.RepeaterItemEventArgs) Handles myRepeater.ItemDataBound

    If (e.Item.ItemType = ListItemType.Item Or e.Item.ItemType = ListItemType.AlternatingItem) Then

        Dim uG As URLGroup = CType(e.Item.DataItem, URLGroup)
        '' you now have the group for that one item
        '' you should now be able to get additional information needed.
        '' you can also get the myLabel from this item 
        dim lbl as Label = CType(e.Item.FindControl("myLabel", Label)
        '' and set its text to whatever you need
        lbl.Text = MyCounter

    End If

End Sub

Hopefully this will get you on your way.

Here is a link to the MSDN documentation for it too.

Answer 2

I used the OnItemDataBount event

<asp:Repeater runat="server" ID="rptGroup" OnItemDataBound="rptDestinationCount_ItemDataBound">
    <HeaderTemplate>
        <table id="tblUrlGroup" class="table table-bordered table-striped table-condensed">
            <thead>
                <tr>
                    <th>Name</th>
                    <th style="width:20px;">Count</th>
                    <th style="width:35px;">Add</th>
                </tr>
            </thead>
            <tbody>
    </HeaderTemplate>
    <ItemTemplate>
            <tr>
                <td><a href="ManageGroup.aspx?Id=<%# DataBinder.Eval(Container.DataItem, "URLGroupRowID") %>"><i class="icon-wrench" rel="tooltip" title="Edit Group Name"></i></a> <a href="DestinationGroup.aspx?Id=<%# DataBinder.Eval(Container.DataItem, "URLGroupRowID") %>"><%# DataBinder.Eval(Container.DataItem, "Name") %></a></td>
                <td class="center"><asp:HiddenField runat="server" ID="hidURLGroupRowID" Value='<%# DataBinder.Eval(Container.DataItem, "URLGroupRowID") %>' /><asp:Label runat="server" ID="lblCount"></asp:Label></td>
                <td class="center">                                
                    <a href="DestinationGroup.aspx?Id=<%# DataBinder.Eval(Container.DataItem, "URLGroupRowID") %>"><i class="icon-plus" rel="tooltip" title="Manage Destination URLs"></i></a>
                </td>
            </tr>
    </ItemTemplate>
    <FooterTemplate>
          </tbody>
        </table>
    </FooterTemplate>
</asp:Repeater>     

On the function I made sure I was only looking through the repeater Item and Item Template. The hidden field is set with the ID with the datasource. This allowed me to run a query and set the lblCount.Text to the destination count.

Code Behind

protected void rptDestinationCount_ItemDataBound(object sender, RepeaterItemEventArgs e)
{
    if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)
    {
        using (MarketingWebContentEntities context = new MarketingWebContentEntities())
        {
            Label lblCount = (Label)e.Item.FindControl("lblCount");
            HiddenField hidURLGroupRowID = (HiddenField)e.Item.FindControl("hidURLGroupRowID");
            int groupRowID = Convert.ToInt32(hidURLGroupRowID.Value);

            var destination = (from dest in context.URLDestination
                               where dest.URLGroup.URLGroupRowID == groupRowID
                               select dest).ToList();

            lblCount.Text = destination.Count.ToString();


        }
    }
}