How to display foreign key values in MVC View

Question

I am trying my best to get a simple MVC application to display foreign key values, but I just can't get it to work.

Here's my classes:

public partial class Kingdoms
{
    public Kingdoms()
    {
        this.Provinces = new HashSet<Provinces>();
    }

    [Key]
    public int KingdomID { get; set; }
    public string Kingdom { get; set; }
    public Nullable<int> KingdomNr { get; set; }
    public Nullable<int> IslandNr { get; set; }
    public Nullable<System.DateTime> Created { get; set; }
    public Nullable<System.DateTime> Modified { get; set; }
    public bool AtWar { get; set; }
    public string Stance { get; set; }

    public virtual ICollection<Provinces> Provinces { get; set; }
}

public partial class Provinces
{
    public Provinces()
    {
        this.ProvinceData = new HashSet<ProvinceData>();
    }

    [Key]
    public int ProvinceID { get; set; }
    public int KingdomID { get; set; }
    public string Province { get; set; }
    public string Race { get; set; }
    public Nullable<int> Land { get; set; }
    public Nullable<int> Networth { get; set; }
    public Nullable<System.DateTime> Created { get; set; }
    public Nullable<System.DateTime> Modified { get; set; }

    public virtual Kingdoms Kingdoms { get; set; }
    public virtual ICollection<ProvinceData> ProvinceData { get; set; }
}

This is in my Controller:

public ActionResult SearchIndex(int networthfrom = 0, int networthto = 0, int landfrom = 0, int landto = 0, int nwafrom = 0, int nwato = 0)
    {
        var provinces = from p in db.Provinces select p;
        return View(provinces);
    }

Now, I have to say that I am using the Add View option in Visual Studio 2012 from this ActionResult. The default View (SearchIndex.cshtml) will show:

@Html.DisplayFor(modelItem => item.KingdomID)

Which will show the ID of the Kingdom. But I want to show the string value Kingdom from Kingdoms class. I have tried the following:

@Html.DisplayFor(modelItem => item.Kingdoms.Kingdom)

But that just generates this: Error. An error occurred while processing your request.

I am publishing this application to Azure FYI.

Solution

Rewrite your action:

public ActionResult SearchIndex(int networthfrom = 0, int networthto = 0, int landfrom = 0, int landto = 0, int nwafrom = 0, int nwato = 0)
    {
        var provinces = db.Provinces.Include(p=>p.Kingdoms);
        return View(provinces);
    }

and use in view

@Html.DisplayFor(modelItem => item.Kingdoms.Kingdom)

Comments

[kerzek]

Is the error a Null reference exception? If so, it could be because Kingdoms are not loaded (lazy loading). I'd suggest creating a view model, and use it in the view

[JBeagle]

ViewModels and AutoMapper are your friends. I suggest a good read up on these.