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PODropdownListFor - Null Reference Exception on page model
 

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  1. PODropdownListFor - Null Reference Exception on page model
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    <p>I'm trying to save one of my Models to the database. Given the models:</p> <pre><code>public class Foo { public int Id { get; set; } public string Name { get; set; } public virtual Bar Something { get; set; } } public class Bar { public int Id { get; set; } public string Name { get; set; } } public class FooPageModel { public Foo F { get; set; } public List&lt;SelectListItem&gt; Bars { get; set; } } </code></pre> <p>In my controller I have:</p> <pre><code>public ActionResult Add(){ var bars = ... // get all bars from db context var barsList = new List&lt;SelectListItem&gt;(); barsList.AddRange(bars.Select(b =&gt; new SelectListItem { Text = b.Name, Value = b.Name })); var model = new FooPageModel { Bars = barsList }; return View("Add", model); } </code></pre> <p>Now for the View (strongly typed to FooPageModel):</p> <pre><code>&lt;%: Html.DropdownListFor(f =&gt; f.F.Bar, Model.Bars) %&gt; </code></pre> <p>The view renders fine, with the values I expect, but when I submit the page form, I get a NullReferenceException (on the view line pasted above before the action on the controller is ever reached). I thought maybe if I modified my controller code to:</p> <pre><code>var model = new FooPageModel { F = new Foo(), Bars = barsList } </code></pre> <p>However, this fails as well. I suppose I could re-write FooPageModel to just be a list of strings of the information I want, but it seems redundant to duplicate Model logic; I'm pretty new to CTP in general, so maybe that's how it's done?</p> <p>I was able to code up something similar for a ComplexType (an address Model) and had no problems. If the stack trace would be helpful, let me know and I'll post it. Thanks in advance.</p>
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    1. USJon
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    1. COSolved: It's my fault for only putting psuedo code up and not the actual code. The problem was that in my model, I had a couple of int and float objects. These are created in the database as non-nullable types. I changed my model to use int? and float? and everything seems to be ok.
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      1. PODropdownListFor - Null Reference Exception on page model
      1. USJon
 

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Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

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