How to use ODataQueryOptions with $ expand

Question

I used the following code to enter Odata style parameters into the query. This works fine until I try to use $ expand and I get an error when casting

Cannot use an object of type 'System.Data.Entity.Infrastructure.DbQuery 1[System.Web.Http.OData.Query.Expressions.SelectExpandBinder+SelectAllAndExpand 1 [STOS.Repository.Entities.Item]]' to enter 'System.Collections. Generic.IEnumerable`1 [STOS.Repository.Entities.Item].

  public static List<T> ApplyTo<T>(HttpRequestMessage request, IQueryable<T> query) { var context = new ODataQueryContext(TheEdmModel(), typeof(T)); var newOptions = new ODataQueryOptions<T>(context, request); return ((IEnumerable<T>)newOptions.ApplyTo(query)).ToList(); } 

I understand that when $ expand is used, another wrapper class is returned, but how can I convert it to a list?

Answer 1

Please follow this sample https://aspnet.codeplex.com/SourceControl/latest#Samples/WebApi/OData/v3/ODataQueryableSample/ : public class OrderController: ApiController

 public IQueryable<Order> Get(ODataQueryOptions queryOptions) { // Register a custom FilterByValidator to disallow custom logic in the filter query if (queryOptions.Filter != null) { queryOptions.Filter.Validator = new RestrictiveFilterByQueryValidator(); } // Validate the query, we only allow order by Id property and // we only allow maximum Top query value to be 9 ODataValidationSettings settings = new ODataValidationSettings(){ MaxTop = 9 }; settings.AllowedOrderByProperties.Add("Id"); queryOptions.Validate(settings); // Apply the query return queryOptions.ApplyTo(OrderList.AsQueryable()) as IQueryable<Order>; }