Problem with using a ToExpando method - asp.net-mvc

Question

Hi I i try to use a ToExpando solution to use anonymous classes in razor views.
I use this solution -> Dynamic Anonymous type in Razor causes RuntimeBinderException
I'll write what i did:
I added a file Extensions.cs where i put following code:
public static class Extensions
{
public static ExpandoObject ToExpando(this object anonymousObject)
{
IDictionary<string, object> anonymousDictionary = HtmlHelper.AnonymousObjectToHtmlAttributes(anonymousObject);
IDictionary<string, object> expando = new ExpandoObject();
foreach (var item in anonymousDictionary)
expando.Add(item);
return (ExpandoObject)expando;
}
}
I wrote a query that receive a tuples from database in controller method:
IEnumerable<dynamic> articles = (from p in db.Articles.Where(p => p.user_id == 2)
select new
{
p.article_id,
p.title,
p.date,
p.category,
AverageScore = db.Articles_Scores
.Where(o => o.user_id == p.user_id && p.article_id == o.article_id)
.Average(m => m.score)
}).AsEnumerable()
.Select(r => r.ToExpando());
int ii = 0;
foreach(var it in articles) {
// HERE I CAN READ EVERYTHING
ii = it.article_id;
}
return View(articles);
In view I declare a model:
#model IEnumerable<dynamic>
And I try to get every tuples:
#foreach (dynamic item in Model) {
// some code
#item.article_id // HERE IS EXCEPTION
}
In the foreach line I got an Exception:
RuntimeBinderException: 'System.Dynamic.ExpandoObject' does not contain a definition for 'article_id'
What did I do wrong?

Answer 1

You need to call .AsEnumerable() or .ToList() first to force ToExpando to run on the client.

Answer 2

Try:
dynamic articles = (from p in db.Articles.Where(p => p.user_id == 2_
select new
{
p.article_id,
p.title,
p.date,
p.category,
AverageScore = db.Articles_Scores
.Where(o => o.user_id == p.user_id && p.article_id == o.article_id)
.Average(m => m.score)
}).AsEnumerable()
.Select(r => r.ToExpando());
Edit: Make sure you declare dynamic not var
Edit 2: In your for look, you're declaring var again. Change it to:
#foreach (dynamic item in Model) {
// some code
#item.article_id // HERE IS EXCEPTION
}

Answer 3

Ok, building on the first two answers, I added another extension method that I'm surprised I don't see here:
public static List<ExpandoObject> ToExpandoList<T>(this IEnumerable<T> ie) {
return ie.Select(o => o.ToExpando()).ToList();
}
And now in my view I have code like this, and it works just fine using Razor.
var peoples = from f in "tom dick susan roberto".Split(' ')
select new { FirstName = f, Age = f.Length };
ViewBag.People = peoples.ToExpandoList();

Answer 4

The problem is HtmlHelper.AnonymousObjectToHtmlAttributes(), it's replacing
'_' with '-' for the property name. Look at the comment for the method.