CODEWITHSUNDEEP
c#asp.net-mvcsimple-injector
Adrug
Adrug

Reputation: 303

parameter passed from constructor NRE ASP.NET

I used WebForms (legacy) + ASP.NET MVC + SimpleInjector 

public abstract class CustomBaseController : Controller
{
    protected User user;
    protected IAppDbContext repo;
    public CustomBaseController(User user, IAppDbContext repo)
    {
        this.user = user;
        this.repo = repo;
    }
}
// my controller
[MyCustomAuthorize]
public class MyCustomController : CustomBaseController
{
    public MyCustomController(User user, IAppDbContext repo) : base(user, repo)
    {
    }

    [HttpPost]
    public ActionResult PostMethod()
    {
        user.Name = "NewUserName"; // throw NullReferenceException that user is null
        // some logic
        // some logger
    }
}
// user entity
public class User
{
    public Guid Id { get; protected set; }
    public string Email { get; protected set; }
    public string DisplayName { get; protected set; }

    public string FirstName { get; protected set; }
    public string LastName { get; protected set; }

    // and other properties
}

// Register DI
private static void InitializeContainer()
{
    var container = new Container();
    container.Register<IUserSessionManagement, UserSessionManagement >(Lifestyle.Scoped);
    container.Register<User>(() => container.GetInstance<UserSessionManagement>().UserSession, Lifestyle.Scoped);
    DependencyResolver.SetResolver(new SimpleInjectorDependencyResolver(container));
}

// Wrapper for User 
public class UserSessionManagement : IUserSessionManagement
{
    public User UserSession { get; }
    public UserSessionManagement(IAppDbContext repo)
    {
        UserSession = (HttpContext.Current.Session[SESSION_AUTHENTICATED_USER] as User) ?? new User(Guid.Empty, null, null);
    }
}

I catch NullReferenceException (user is null) on /PostMethod request. I was looking for any place where the reference could wipe. Nothing. Reference cannot rewrite. it looks like GC has cleaned all the links.

NOTE: I cannot reproduce this in debugging. I know about this problem from the logs.

NOTE1: MyCustomController created successful (user is not null). Post request to throw expection that user is null.

Upvotes: 0

Views: 75

Answers (1)

Leonardo Wildt
Leonardo Wildt

Reputation: 2599

Take a look at this answer Here

We would have to see your CustomBaseController To see more. 

public MyCustomController() : base()
{
}

You may just need a parameterless constructor.

Upvotes: -1

Related Questions