HttpPost actionResult says object is null

Question

Im trying to insert a list of players into a team, I have the list of players being sent to the controller and am picking them up, I then Create a new Team but when I go to add each player I get an error thrown saying: An exception of type 'System.NullReferenceException' occurred in EloraCurling.dll but was not handled in user code

Additional information: Object reference not set to an instance of an object.

Here is the code for my ActionResult:

[HttpPost]
    [ValidateAntiForgeryToken]
    public ActionResult CreateLeagueTeam(ICollection<int> members)
    {
        Team team = new Team();

        team.IsBonspiel = false;
        team.IsLeague = true;

        //sets the year the team is created
        team.YearActive = games.getSeasonYear();
        //finds and sets the league ID for the team
        int leagueId = (int)Session["leagueId"];
        League league = db.Leagues.Find(leagueId);
        team.League = league;

        //adds each member to the team
        foreach (int memberId in members)
        {
            Member newMember = new Member();
            newMember = db.Members.Find(memberId);
            newMember.Teams.Add(team);

            //team.Members.Add(newMember);
        }
        //gets the first member in the list and makes that member the skip
        int skipId = members.First();
        Member skip = db.Members.Find(skipId);
        //assigns the member to the skip position and sets the team name
        team.Skip = skip;
        team.Name = skip.LastName;



        if (ModelState.IsValid)
        {
            db.Teams.Add(team);
            db.SaveChanges();
            return RedirectToAction("Index");
        }
    }

The Member Model:

 public class Member : Entity
{
    [Display(Name = "First Name")]
    public string FirstName { get; set; }

    [Display(Name = "Last Name")]
    public string LastName { get; set; }

    public string Address { get; set; }

    public string City { get; set; }

    public string PostalCode { get; set; }

    public DateTime? DateOfBirth { get; set; }

    public ApplicationUser User { get; set; }

    public bool HasSmartServe { get; set; }

    public string SmartServeNumber { get; set; }

    public bool IsActive { get; set; }

    public bool IsEnabled { get; set; }

    public string User_Id { get; set; }

    public List<MembershipEntry> MembershipEntries { get; set; }

    public List<Team> Teams { get; set; }

    public List<League> Leagues { get; set; }

    public List<Committee> Committees { get; set; }
}

I am getting the members and can see that it is an object but not sure why it will not add.

Mrinal Kamboj · Accepted Answer · 2016-04-11T16:43:38.853

0

Is the error on this line:

newMember.Teams.Add(team);

then that is because Teams of type List<Team> needs initialization before usage, something like:

newMember.Teams = new List<Team>();

// Now call inside same loop

newMember.Teams.Add(team);

this is purely on the basis of quick review of the code, I am not too sure regarding the business logic, where you want to assign an already created list object to the newMember.Teams, but this surely needs initialization before a Add method can be called to add another team

edited Apr 11 '16 at 16:43

answered Apr 11 '16 at 16:37

Mrinal Kamboj

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Mrinal is probably right. As a helper, usually when I have lists in my objects, I will make sure that the class has a parameterless constructor to initialize any and all lists. – Jonathan Apr 11 '16 at 16:40

score 0 · Answer 2 · answered Apr 11 '16 at 16:38

You are not initializing your Teams property in your Member. Simply add a default constructor for Member and initialize the Teams to an empty List<Team>:

public class Member : Entity
{
    public void Member()
    {
       Teams = new List<Team>();
    }

    public List<Team> Teams { get; set; }

HttpPost actionResult says object is null

2 Answers2