详情查看asp.net mvc5 外值为空

Question

I have the problem, that foreign values are not visible in my view.

The value of TestId is correct in the DB but in the details view not correct visible.

My view (in the browser) doesn`t show eny value for TestName.

My model classes:

public class Issue
{
    public int Id { get; set; }

    public string Title { get; set; }

    public int TestId { get; set; }
    public Test Test { get; set; }
}


public class Test
{
    public int TestId { get; set; }
    public string TestName { get; set; }

    public List<Issue> Issues { get; set; }
}

My Issue Contorller:

// GET: Issues
public ActionResult Index()
{
    var issues = db.Issues.Include(i => i.Test);
    return View(issues.ToList());
}

// GET: Issues/Details/5
public ActionResult Details(int? id)
{
    if (id == null)
    {
        return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
    }
    Issue issue = db.Issues.Find(id);
    if (issue == null)
    {
        return HttpNotFound();
    }
    return View(issue);
}

My Details View:

<dl class="dl-horizontal">
    <dt>
        Title
    </dt>
    <dd>
        @Html.DisplayFor(model => model.Title)
    </dd>
    <dt>
        Test
    </dt>
    <dd>
        @Html.DisplayFor(model => model.Test.TestName)
    </dd>
</dl>

The model.Title works great without any problems. In my DB of issue model I can see:

ID  Title   TestId 
1   Test1   1
2   Test2   3
3   Test3   5

Answer 1

You should use Include to load navigation property.

Issue issue = db.Issues.Include(a => a.Test).FirstOrDefault(a => a.Id == id);