MVC 'Model' threw an exception of type 'System.NullReferenceException'

Asked Mar 04 '19 at 15:11

Active Mar 04 '19 at 15:30

Viewed 1,251 times

I have a _Layout file that contains this. The _HeaderModel class gets initialized correctly.

<partial name="_Header" model='new _HeaderModel((int?)ViewData["ActiveIndex"])' />

_Header contains

@page
@model Project.Pages.Shared._HeaderModel
@Model.ActiveIndex

I get this error:

'Model' threw an exception of type 'System.NullReferenceException'

Model isn't even a null reference; trying to access the property throws this exception. I really can't do it any more basic. What am I doing wrong?

Edit: This has nothing to do with the generic NullReferenceException thread. I know what a NullReferenceException is (duh) but why would it be happening here? This is a very specific case that regards ASP.NET Core 2.

edited Mar 04 '19 at 15:30

Liam

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asked Mar 04 '19 at 15:11

Etienne Charland

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Is it ASP.NET Core, right? And are you using controller + view? – Alexander Mar 04 '19 at 15:14
ASP.NET Core 2.2, using plain Razor page. I know what a NullReferenceException is (duh) but why would it happen here? – Etienne Charland Mar 04 '19 at 15:15
Have you tried to specify full name in `partial` to page like `/Page/Shared/_Header`? – Alexander Mar 04 '19 at 15:20
That doesn't change anything, except that I must then add .cshtml at the end – Etienne Charland Mar 04 '19 at 15:26
What is `@Model.ActiveIndex` supposed to be (or do) ? – Henk Holterman Mar 04 '19 at 15:39
Does the HeaderModel constructor set the activeindex or leave it an uninitialized null? – Mark Fitzpatrick Mar 04 '19 at 15:44
The constructor sets it; but you never get to read that property because I can't even get a reference to Model. Constructor: public _HeaderModel(int? activeIndex) { this.ActiveIndex = activeIndex; } – Etienne Charland Mar 04 '19 at 16:02
Why did 2 people vote to close the question without having any clue about the answer? – Etienne Charland Mar 04 '19 at 16:18
4

Oh, found the answer here!! Removing @page at the top of the partial view fixes it https://stackoverflow.com/a/52014029/3960200 – Etienne Charland Mar 04 '19 at 16:21

MVC 'Model' threw an exception of type 'System.NullReferenceException'

0 Answers0