Html.DisplayNameFor背后的逻辑是什么

Question

Today I'm noticed strange behavior in scaffolded razor views, which have IEnumerable<Item> model.

Even if model is a IEnumerable it's use single item notation for the table header

@model IEnumerable<Item>

<table class="table">
    <tr>
        <th>
            @Html.DisplayNameFor(model => model.Genre)
        </th>
        ... 
        <th>
            @Html.DisplayNameFor(model => model.Price)
        </th>
        <th></th>
    </tr>

    @foreach (var item in Model)
    {
        <tr> ... </tr>
    }
...

How it's itself 'unpack' collection to a single items and if it's so clever, what else it could do?

Answer 1

It's using this overload:

public static MvcHtmlString DisplayNameFor<TModel, TValue>(
    this HtmlHelper<IEnumerable<TModel>> html,
    Expression<Func<TModel, TValue>> expression
)

(see MSDN )

You can use the extension method on an IEnumerable<T> , while the lambda uses just the T to get at the property.