How do I use Eval() to reference values in a SortedDictionary in an asp Repeater?

Question

I thought I was clever to switch from the memory intensive DataView to SortedDictionary as a memory efficient sortable data structure. Now I have no idea how get the key and value out of the datasource in the <%# or Eval() expressions.

SortedDictionary<int, string> data = RetrieveNames();
rCurrentTeam.DataSource = data;
rCurrentTeam.DataBind();

<asp:Repeater ID="rNames" runat="server">
 <ItemTemplate>
  <asp:Label ID="lblName" runat="server" Text='<%# Eval("what?") %>' />
 </ItemTemplate>
</asp:Repeater>

Any suggestions?

Answer 1

Use either of these two options:

<%# Eval("Key") %>
<!-- or -->
<%# Eval("Value") %>

depending on whether you need the key or the value from the dictionary.

This makes sense if you think about how data binding works. Data binding is a process by which a control takes an enumerable sequence, iterates that sequence, and uses reflection to extract values from each item in the sequence based on properties that the item exposes.

Since SortedDictionary<TKey,TValue> implements the IEnumerable<KeyValuePair<TKey, TValue>> interface you know that the repeater will enumerate a sequence of KeyValuePair<TKey, TValue> objects, binding to each one in turn.

If you look at the properties that are exposed by the KeyValuePair<TKey,TValue> class you will see just two: Key and Value. Since they are public properties you can Eval them and the control will be able to extract the values that they encapsulate.