Question

So I have this model setup

public class ListOfThings
{
    public int Id {get;set;}
    public List<int> DefaultRanks {get;set;}

    static public IEnumerable<ListOfThings> ListOfDefault{
       get {
            listOfDefault = new List<ListOfDefault>();
            listOfDefault.Add(N1);
            listOfDefault.Add(N2);
            listOfDefault.Add(N3);
            return listOfDefault.AsReadOnly();
       }
    }

    static public ListOfThings N1{ get { return new ListOfThings { Id = 1, Addend = new List<int> { 1 }}; } }  
    static public ListOfThings N2{ get { return new ListOfThings { Id = 2, Addend = new List<int> { 1,2 }}; } }
    static public ListOfThings N3{ get { return new ListOfThings { Id = 3, Addend = new List<int> { 1,2,3 }}; } }

    static private ListOfThings n1;
    static private ListOfThings n2;
    static private ListOfThings n3;
    static private List<ListOfThings> listOfDefault;
}

And whenever I try to query that static Ienumerable, it’ll give me a null value.

var test = ListOfThings.ListOfDefault.Where(a => a.Id == 2);

And if I try to do this, it’ll give me a cast warning.

ListOfThings test = ListOfThings.ListOfDefault.Where(a => a.Id == 2);

Any advice is appreciated..

Thanks!!
-G

Answer 1

There are some problems in your code. The changes I made are:

// in a getter
listOfDefault = new List<ListOfDefault>(); 
// should be:
listOfDefault = new List<ListOfThings>();

// static getters
static public ListOfThings N1{ get { return new ListOfThings { Id = 1, Addend = new List<int> { 1 }}; } }  
static public ListOfThings N2{ get { return new ListOfThings { Id = 2, Addend = new List<int> { 1,2 }}; } }
static public ListOfThings N3{ get { return new ListOfThings { Id = 3, Addend = new List<int> { 1,2,3 }}; } }
// should be:

static public ListOfThings N1 { get { return new ListOfThings { Id = 1, DefaultRanks = new List<int> { 1 } }; } }
static public ListOfThings N2 { get { return new ListOfThings { Id = 2, DefaultRanks = new List<int> { 1, 2 } }; } }
static public ListOfThings N3 { get { return new ListOfThings { Id = 3, DefaultRanks = new List<int> { 1, 2, 3 } }; } }

And the most important is you don’t call the FirstOrDefault() on your LINQ (if you want to get more objects use ToList() ):

var test = ListOfThings.ListOfDefault.Where(a => a.Id == 2).FirstOrDefault();

This way it should work.