ASP.NET RazorPages: System.NullReferenceException: 'Object reference not set to an instance of an object.'

Question

I'm very new to ASP.NET and I'm trying some things out right now. I try to make a simple dashboard right now which displays some set numbers, but I get this System.NullReferenceException The whole day I try to fix this, but it keeps throwing this exception.

index.cshtml:

@model XSP.ViewModels.DashboardViewModel

              <img src="assets/images/plane-icon.png" alt="deliver-icon">
                                    </span>
                                    <h2>Errors</h2>
                                </div><!--/.icon-box-->
                                <h3>@Model.errors</h3>
                                <p>0 This Week</p>
                            </div><!--/.profile-state-->
                        </div><!--/.col-->

My HomeController where the values are getting filled:

    public class HomeController : Controller
    {
        public IActionResult Index()
        {
            DashboardViewModel dashboard = new DashboardViewModel();

            dashboard.onlineplayers = 1;
            dashboard.errors = 222;
            return View(dashboard);
        }
    }

And here's my ViewModel

    public  class DashboardViewModel
    {
        public  int onlineplayers { get; set; };
        public  int errors { get; set; };
    }

I already checked the other threads before I asked this question where the solution was always in the Controller adding return View(XX); but I have a return value.

Thanks for your help :)

I alredy saw that post and no it did not help me (maybe I'm just too stupid). This line throws the exception: `
@Model.errors
` — Hakuryuu, May 22 '21 at 18:52
Try debugging `Index` method and see whether the `dashboard` object is being passed correctly. I think that the page you're rendering is not actually `Index` page, but some other. That's why you're getting `nullreference` — Miraziz, May 22 '21 at 19:47
You mean in the HomeController? If yes, no it does not get passed. — Hakuryuu, May 22 '21 at 19:55

Pritom Sarkar · Accepted Answer · 2021-05-22T20:35:46.170

0

try this, I think it resolves your issue.

you should ignore ; in your class.

 public  class DashboardViewModel
    {
        public  int onlineplayers { get; set; }
        public  int errors { get; set; }
    }

Update

The solution is just remove the @page keyword.For example a Index.cshtml razor page will get it's model from Index.cshtml.cs file method.

edited May 22 '21 at 20:35

answered May 22 '21 at 18:54

Pritom Sarkar

2,154
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Hi, no it does not fix my problem. Error is same as before. – Hakuryuu May 22 '21 at 19:05
Pls, explain the difference between this and PO code? – Serge May 22 '21 at 19:17
@Hakuryuu I updated my answer.please check – Pritom Sarkar May 22 '21 at 19:20
@Serge it's not different totally. just for experiment. – Pritom Sarkar May 22 '21 at 19:22
I already removed those. Still same error. – Hakuryuu May 22 '21 at 19:28
Can you add this line ```@using XSP.ViewModels```? in _Viewimports.cshtml? – Pritom Sarkar May 22 '21 at 19:33
@Hakuryuu my machine works perfectly in your code now. – Pritom Sarkar May 22 '21 at 19:40
I added `@using XSP.ViewModels` but it still throws the exception – Hakuryuu May 22 '21 at 19:40
rebuild your project, if not works then please share your ```index.cshtml``` all code. – Pritom Sarkar May 22 '21 at 19:42
Did not fix the issue. Full index.cshtml: https://pastebin.com/utww6Z6N – Hakuryuu May 22 '21 at 19:49
why you actually used this ```@page```.no need here. remove it into all of your views, ```@page``` then it works. – Pritom Sarkar May 22 '21 at 20:14
It was added automatically. When I remove it and compile it it says this: http://prntscr.com/139yz0h – Hakuryuu May 22 '21 at 20:18
please check your route. it's your routing problem. check ```startup.cs```.can you added extra Area in your application? and is your application asp.net core MVC ? – Pritom Sarkar May 22 '21 at 20:29
please check ```startup.cs``` ```app.UseMvc(routes => { routes.MapRoute( name: "default", template: "{controller=Home}/{action=Index}/{id?}"); });``` by the way,you have to obviously remove ```@page```. – Pritom Sarkar May 22 '21 at 20:32
Yeah I just added that a few minutes ago. It catches now the controller and removing the @page fixed the issue! Thank you! – Hakuryuu May 22 '21 at 20:35

ASP.NET RazorPages: System.NullReferenceException: 'Object reference not set to an instance of an object.'

@Model.errors

1 Answers1