I am trying to build a dropdown list for a winform interop, and I am building the dropdown in code. However, I am having a problem getting the data to bind based on the DataTemplate I specify.

What am I missing?

drpCreditCardNumberWpf = new ComboBox();

            DataTemplate cardLayout = new DataTemplate {DataType = typeof (CreditCardPayment)};
            StackPanel sp = new StackPanel
                                {
                                    Orientation = System.Windows.Controls.Orientation.Vertical
                                };

            TextBlock cardHolder = new TextBlock {ToolTip = "Card Holder Name"};
            cardHolder.SetBinding(TextBlock.TextProperty, "BillToName");
            sp.Children.Add(cardHolder);

            TextBlock cardNumber = new TextBlock {ToolTip = "Credit Card Number"};
            cardNumber.SetBinding(TextBlock.TextProperty, "SafeNumber");
            sp.Children.Add(cardNumber);

            TextBlock notes = new TextBlock {ToolTip = "Notes"};
            notes.SetBinding(TextBlock.TextProperty, "Notes");
            sp.Children.Add(notes);

            cardLayout.Resources.Add(sp, null);

            drpCreditCardNumberWpf.ItemTemplate = cardLayout;