Null check doesn't work as expected in Razor

Question

I have these models :

public class Project
{
    public int ProjectID { get; set; }
    public string ProjectTitle { get; set; }
    public string ProjectDetails { get; set; }
    public Bid SelectedBid { get; set; }

    public virtual ICollection<Bid> Bids{ get; set; }

}
public class Bid
{
    public int BidID { get; set; }
    public string BidTitle { get; set; }
    public string BidDetails { get; set; }

    public virtual Project Project { get; set; }
}

And I have this Razor :

@if(Model.SelectedBid == null)
{
   <dt>
      Status : 
   </dt>

   <dd>        
      Bid not Selected
   </dd>
}
else
{
   <dt>
      Status : 
   </dt>

   <dd>
      Bid Selected.
   </dd>    
}

While debugging in the View, Model has this selected bid :

base = {System.Data.Entity.DynamicProxies.Bid_88FA74D99E4E553A1039D70D55E452C7931E74DCCCA8B5237C0A208B12CCA8C4} But it still accepts null situation.

Here is my controller :

 public ActionResult Details(int? id)
    {
        if (id == null)
        {
            return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
        }
        Project project = db.Projects.Find(id);
        return View(project);
    }

Can you tell me what is wrong with this code? Thanks.

you should debug the view, and check if SelectedBid is null or not — Fabio
– Fabio, Commented Dec 17, 2015 at 13:12
@FabioLuz I checked in the View, it's still not null. But it says bid not selected. — jason
– jason, Commented Dec 17, 2015 at 13:16
@jason did you mean the SelectedBid is not null and the comparison SelectedBid == null is returning true? — Fabio
– Fabio, Commented Dec 17, 2015 at 13:20

Sam FarajpourGhamari · Accepted Answer · 2015-12-17 13:47:20Z

3

Try this in your action method:

Project project = db.Projects
    .Include(p=>p.SelectedBid)
    .FirstOrDefault(p=>p.ProjectID==Id);

Also don't forget to add System.Data.Entity namespace.

answered Dec 17, 2015 at 13:47

Sam FarajpourGhamari

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2 Comments

jason Over a year ago

Thanks, worked like a charm. Can you tell the magic of Include?

Sam FarajpourGhamari Over a year ago

EF doesn't fetch relative objects which associated with requested object from DB. Instead make a proxy object to lazy load the object. Therefore when you check Model.SelectedBid == null it returns true because it is not loaded yet and obviously null. But if you debug the code you can see actual data not a null object because debugger loaded the object while you debug the code. By adding include we say to EF fetch included object also and doesn't lazy load it.

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