Silverlight 4 Overriding the DataForm Autogenerate to insert Combo Boxes bound to Converters - silverlight-4.0

Question

I've been working towards a solution for some time and could use a little help. I know I've seen an example of this before, but tonight I cannot find anything close to what I need.
I have a service that provides me all my DropDownLists, either from Cache or from the DomainService. They are presented as IEnumerable, and are requested from the a repository with GetLookup(LookupId).
I have created a custom attribute that I have decorated my MetaDataClass that looks something like this:
[Lookup(Lookup.Products)]
public Guid ProductId
I have created a custom Data Form that is set to AutoGenerateFields and I am intercepting the autogenerate fields.
I am checking for my CustomAttribute and that works.
Given this code in my CustomDataForm (standard comments removed for brevity), what is the next step to override the field generation and place a bound combobox in its place?
public class CustomDataForm : DataForm
{
private Dictionary<string, DataField> fields = new Dictionary<string, DataField>();
public Dictionary<string, DataField> Fields
{
get { return this.fields; }
}
protected override void OnAutoGeneratingField(DataFormAutoGeneratingFieldEventArgs e)
{
PropertyInfo propertyInfo = this.CurrentItem.GetType().GetProperty(e.PropertyName);
foreach (Attribute attribute in propertyInfo.GetCustomAttributes(true))
{
LookupFieldAttribute lookupFieldAttribute = attribute as LookupFieldAttribute;
if (lookupFieldAttribute != null)
{
// Create a combo box.
// Bind it to my Lookup IEnumerable
// Set the selected item to my Field's Value
// Set the binding two way
}
}
this.fields[e.PropertyName] = e.Field;
base.OnAutoGeneratingField(e);
}
}
Any cited working examples for SL4/VS2010 would be appreciated.
Thanks
Update - Here's where I am at. I get my combo now, but it's always empty even though itemsSource is not.
if (lookupFieldAttribute != null)
{
ComboBox comboBox = new ComboBox();
Binding newBinding = e.Field.Content.GetBindingExpression(TextBox.TextProperty).ParentBinding.CreateCopy();
newBinding.Mode = BindingMode.TwoWay;
newBinding.Converter = new LookupConverter(lookupRepository);
newBinding.ConverterParameter = lookupFieldAttribute.Lookup.ToString();
comboBox.SetBinding(ComboBox.SelectedItemProperty,newBinding);
comboBox.ItemsSource = lookupRepository.GetLookup(lookupFieldAttribute.Lookup);
e.Field.Content = comboBox;
}

Answer 1

I found a solution.
if (lookupFieldAttribute != null)
{
ComboBox comboBox = new ComboBox();
Binding newBinding = e.Field.Content.GetBindingExpression(TextBox.TextProperty).ParentBinding.CreateCopy();
var itemsSource = lookupRepository.GetLookup(lookupFieldAttribute.Lookup);
var itemsSourceBinding = new Binding { Source = itemsSource };
comboBox.SetBinding(ItemsControl.ItemsSourceProperty, itemsSourceBinding);
newBinding.Mode = BindingMode.TwoWay;
newBinding.Converter = new LookupConverter(lookupRepository);
newBinding.ConverterParameter = lookupFieldAttribute.Lookup.ToString();
comboBox.SetBinding(ComboBox.SelectedItemProperty,newBinding);
e.Field.Content = comboBox;
}