converting a composite collection with collection container from xaml to C#

Question

Basically I want to convert something I did in xaml to C#. This is related to the following issue: Bind a string in xaml to a property

Here is why the proxy is needed and used in my case: http://www.thomaslevesque.com/2011/03/21/wpf-how-to-bind-to-data-when-the-datacontext-is-not-inherited/

Proxy class to allow me to bind to the CollectionContainer:

public class BindingProxy : Freezable
{
    #region Overrides of Freezable

    protected override Freezable CreateInstanceCore()
    {
        return new BindingProxy();
    }

    #endregion

    public object Data
    {
        get { return (object)GetValue(DataProperty); }
        set { SetValue(DataProperty, value); }
    }

    // Using a DependencyProperty as the backing store for Data.  This enables animation, styling, binding, etc...
    public static readonly DependencyProperty DataProperty =
        DependencyProperty.Register("Data", typeof(object), typeof(BindingProxy), new UIPropertyMetadata(null));
}

Proxy defined in my control's resources:

<UserControl.Resources>
   <global:BindingProxy x:Key="proxy" Data="{Binding }" />
</UserControl.Resources>

Xaml code that I ultimately want to convert to C#:

<ComboBox ItemsSource="{Binding NameCollection}">
   <ComboBox.ItemsSource>
      <CompositeCollection>
         <x:StaticExtension Member="VM:NameClass.NoName " />
         <CollectionContainer Collection="{Binding Data.NameCollection, Source={StaticResource proxy}}" />
      </CompositeCollection>
   </ComboBox.ItemsSource>
 </ComboBox>

String Constant that I don't want in my View Model collection, but want shown to the user:

public class NameClass
{
   public const string NoName = "[None]";
}

Answer 1

I think I was over complicating it, by trying to include the proxy. But really it was a pretty simple solution:

 ComboBox comboBox1 = new ComboBox { Height = 18, Width = 100, FontSize = 9.5 };

 CompositeCollection compositeCollection = new CompositeCollection();
 compositeCollection.Add(NameClass.NoName);

 CollectionContainer collectionContainer = new CollectionContainer();
 collectionContainer.Collection = ItemsSource1;

 compositeCollection.Add(collectionContainer);

 comboBox1.ItemsSource = compositeCollection;