IList<T> to IQueryable<T>
Solution 1:
List<int> list = new List<int>() { 1, 2, 3, 4, };
IQueryable<int> query = list.AsQueryable();
If you don't see the AsQueryable() method, add a using statement for System.Linq.
Solution 2:
Use the AsQueryable<T>() extension method.