Expression.Call - Calling linq extension: FirstOrDefault, Where

Question

I am trying to create the following dynamically, however I am having problems calling the extension method FirstOrDefault:

 using(var context =          


        

Answer 1

Are you sure e.Cars is an IQueryable<T>?

If not, you can't pass it to Queryable.FirstOrDefault<T>(IQueryable<T>).

If it's an IEnumerable<T>, change your code to call Enumerable.FirstOrDefault<T>(IEnumerable<T>):

 var result =
     Expression.Call(
         typeof(Enumerable),
         "FirstOrDefault",
         new Type[] { TypeSystem.GetElementType(property.Type) },
         property);