自己感觉这种方法挺简洁的:
<asp:Repeater ID="Repeater_A" runat="server">
<ItemTemplate>
<!-- Add your Item Template Here -->
</ItemTemplate>
<FooterTemplate>
<asp:Label ID="lblEmpty" Text="No Result" runat="server" Visible='<%#bool.Parse((Repeater_A.Items.Count==0).ToString())%>'>
</asp:Label>
</FooterTemplate>
</asp:Repeater>