How can I hide a repeater in ASP.NET C# if the DataSource contains no items?

Question

I have an ASP.NET page that uses a repeater nested within another repeater to generate a listing of data. It\'s to the effect of the following:

Answer 1

I don't think what you are doing is going to work I get an error when I try and set the DataSource as you are trying to do; however, in the code behind you do this:

Assuming you added a listener to your parent repeater's ItemDataBoundEvent, then you will need to change your linq query slightly to not use an anonymous type (Create a protected class that has your properties) In mjy case I am using dto as the class name.

void rep1_ItemDataBound(object sender, RepeaterItemEventArgs e)
{

    Repeater rep2 = (Repeater)e.Item.FindControl("rep2");
    rep2.DataSource = ((dto)e.Item.DataItem).y;
    rep2.DataBind();
}

I'd love to learn why you think you can't solve this in the code behind.

Answer 2

use this:

protected void Repeater1_PreRender(object sender, EventArgs e)
{
    if (Repeater1.Items.Count < 1)
    {
        container.Visible = false;
    }
}

Answer 3

Try something like:

<asp:Repeater runat="server" DataSource='<%#Eval("Data2")%>' 
    Visible='<%# ((IEnumerable)Eval("Data2")).GetEnumerator().MoveNext() %>'>

for the nested repeater

Answer 4

Why not use a ListView? It offers much of the same functionality including an EmptyDataTemplate.

Answer 5

This won't hide the repeater completely, but you can subclass the Repeater control so that it includes a GridView-like empty data template:

using System;
using System.Web.UI;
using System.Web.UI.WebControls;

public class EmptyCapableRepeater : Repeater
{
    public ITemplate EmptyDataTemplate { get; set; }

    protected override void OnDataBinding ( EventArgs e )
    {
        base.OnDataBinding( e );

        if ( this.Items.Count == 0 )
        {
            EmptyDataTemplate.InstantiateIn( this );
        }
    }
}

You can them use it in your .aspx like this:

<custom:EmptyCapableRepeater runat="server" ID="rptSearchResults">
    <ItemTemplate>
        <%# Eval( "Result" )%>
    </ItemTemplate>
    <SeparatorTemplate>
        <br />
    </SeparatorTemplate>
    <EmptyDataTemplate>
        <em>No results were found.</em>
    </EmptyDataTemplate>
</custom:EmptyCapableRepeater>

Answer 6

I know this is an old thread and the answer above is a very nice solution, but I had a similar problem and have found another vary simple solution I thought I would share also. This validates just fine and displays the same.

Just change your footer template to:

<FooterTemplate> 
            <li style="display:none;">This will not show.</li></ul> 
</FooterTemplate> 

Or if your using tables:

<FooterTemplate> 
            <tr> style="display:none;"><td>But something must be in here.</td></tr></table> 
</FooterTemplate> 

Hope that helps someone!