Max value LINQ using class - linq

Question

I've got this class
public class Materiale
{
public string IdMateriale { get; set; }
public string GenereMateriale { get; set; }
public string Categoria { get; set; }
public string Modello { get; set; }
public string Tipo { get; set; }
public string NumSerie { get; set; }
public int Anno { get; set; }
public string DittaCostruttrice { get; set; }
public string Note { get; set; }
public List<Controllo> Controlli = new List<Controllo>();
}
public class Controllo
{
public string IdControllo { get; set; }
public DateTime DataControllo { get; set; }
public string IdMateriale { get; set; }
public string Utente { get; set; }
public string Stato { get; set; }
public string Note { get; set; }
}
I want to query a list of "Materiale" filtering "Controlli". I need to retrieve all properties of the "Materiale" class and only one property of the "Controllo" class (the one named "Stato"). From the list "Controlli" I need the one that has the most recent "DataControllo" property.
I try this in a LINQ query but I receive an error (Max doesn't exist in the current context)
List<Materiale> m = new List<Materiale>();
List<Materiale> m2 = (from ma in m
from c in ma.Controlli
where c.DataControllo == Max(c.DataControllo)
select new
{
ma, c.Stato
}).ToList();
Can someone help me

Answer 1

#Christos is correct, here is my version with let in query syntax:-
List<Materiale> m2 = from m in MaterialeList
let RecentControllo = m.OrderByDescending(x => x.DataControllo)
.FirstOrDefault()
select new Materiale
{
IdMateriale = m.IdMateriale,
GenereMateriale = m.GenereMateriale,
//Similarily other properties of Materiale here
Stato = RecentControllo != null ? RecentControllo.Stato : ""
}).ToList();

Answer 2

I think that you need something more simple like the following one:
List<Materiale> m2 = from ma in m
let mostRecentControllo = ma.Controlli
.OrderByDescending(c=>c.DataControllo)
.FirstOrDefault()
select new
{
Materiale = ma,
Stato = mostRecentControllo != null
? mostRecentControllo.Stato : null
}).ToList();
I have supposed that each Materiale's Controlli list contains Controllo with the same IdMateriale.