Comments on: MVC Beta to RTW upgrade issue – AddModelError and NullReferenceExceptions

By: Sean Yang

Sean Yang — Thu, 03 Dec 2009 09:35:01 +0000

Thank you very much. It works well. Cool!

By: Man

Man — Mon, 19 Oct 2009 16:17:55 +0000

Thank you very much! You’re the boss!

By: Jeff Stewart

Jeff Stewart — Wed, 30 Sep 2009 17:19:07 +0000

Just ran into this very same problem. Very, very odd behavior on MVC’s part. (BTW, my shot-in-the-dark Google search for this problem was “addmodelerror value null”, which led me to this post.)

By: Arjen de Mooij

Arjen de Mooij — Tue, 25 Aug 2009 09:11:17 +0000

Thx, mate, had exactly the same problem

By: pikesville Paesano

pikesville Paesano — Fri, 17 Jul 2009 13:24:17 +0000

Thanks! you saved me a few aspirin!

By: Scott

Scott — Fri, 26 Jun 2009 03:45:46 +0000

Top Jimmy, he’s the king!

By: Greg McNamara

Greg McNamara — Fri, 08 May 2009 02:10:00 +0000

Thanks for that workaround Jimmy! Probably saved me hours of time and some of my hair! I’m overriding the DefaultModelBinder which was affecting the ModelState and causing a NullReferenceException on my dropdown list.

By: Jason Dentler

Jason Dentler — Tue, 21 Apr 2009 14:00:52 +0000

Thanks for that fix Jimmy! I had the same issue with DropDownList. For me specifically, a required drop down list was hidden with jQuery before the form was submitted, so it didn’t post a value. The value never made it to the model state. When I added an error saying the field was required, the HtmlHelper assumed it would have a value just because the key existed in the model state dictionary.

By: Steven Harman

Steven Harman — Fri, 27 Mar 2009 14:43:09 +0000

Jimmy,
At first glance it seems like this might actually be a bug (where bug could be defined as behavior which breaks the “rule of least surprise”) in asp.net mvc, yes? Or is it just simply a side effect of the way your populating/handling error states?

Either way, it seems like something that might come up often enough to warrant some attention & possibly a fix within the asp.net mvc framework. Should we get Phil on the phone?