How to get choices from lookup field using CSOM?

Question

I have an MVC app and am trying to recreate a Lookup site column on a page with a drop down list (add all the choices to the list). The itemColl ends up being empty, is there something that I'm not loading correctly?

SharePointContext spContext = SharePointContextProvider.Current.GetSharePointContext(HttpContext);
ClientContext clientContext = spContext.CreateUserClientContextForSPHost();
Field field = clientContext.Web.Fields.GetByInternalNameOrTitle('InternalName');

clientContext.Load(field);
clientContext.ExecuteQuery();

FieldLookup lkField = clientContext.CastTo<FieldLookup>(field);
clientContext.Load(lkField, f => f.LookupList);
clientContext.ExecuteQuery();

var list = clientContext.Web.Lists.GetById(new Guid(lkField.LookupList));

var itemColl = list.GetItems(CamlQuery.CreateAllItemsQuery());
clientContext.Load(itemColl, items => items.Include(listItem => listItem[lkField.LookupField]));
clientContext.Load(itemColl);
clientContext.ExecuteQuery();

Answer 1

You have to hack into the schema of the field:

ctx.Load(field, (s) => s.SchemaXml);
ctx.ExecuteQuery();
var lookupListId = XElement.Parse(field.SchemaXml)
                              .Attributes()
                              .First(s => s.Name == "List")
                              .Value;

See: Convert Field To FieldLookup using ClientContext