ASP.NET MVC 4 - for 循环发布模型集合属性但 foreach 没有 [英] ASP.NET MVC 4 - for loop posts model collection properties but foreach does not

问题描述

假设我有以下模型:

public class Person
{
    public string Name { get; set; }
    public int Age { get; set; }
}

public class Town
{
    public string Name { get; set; }
    public IEnumerable<Person> People { get; set; }
}

然后，在我的 Razor 视图中，我有这个:

Then, in my Razor view, I have this:

@model Town
@using(Html.BeginForm())
{
    <table>
        @foreach(var person in Model.People)
        {
            <tr>
                <td>@Html.TextBoxFor(m => person.Name)</td>
                <td>@Html.TextBoxFor(m => person.Age)</td>
            </tr>
        }
    <table>
    <input type="submit" />
}

然后，我有一个 POST 操作，如下所示:

Then, I have an action for the POST, something like this:

[HttpPost]
public ActionResult Index(Town theTown)
{
    //....
}

当我发布时，IEnumerable 没有出现.如果我在 Fiddler 中查看它，该集合仅发布一次，并且不会枚举该集合，因此我得到:

When I post, the IEnumerable<Person> does not come across. If I look at it in Fiddler, the collection only posts once, and doesn't enumerate the collection, so I get:

People.Name = "whatever"
People.Age = 99

但是，如果我将 People 更改为 IList 并使用 for 循环而不是 foreach...

However, if I change People to an IList and use a for loop instead of a foreach...

@for(var i = 0;i < Model.People.Count;i++)
{
    <tr>
        <td>@Html.TextBoxFor(m => Model.People[i].Name)</td>
        <td>@Html.TextBoxFor(m => Model.People[i].Age)</td>
    </tr>
}

它有效.难道我做错了什么?我错过了什么?

It works. Am I doing something wrong? What am I missing?

推荐答案

问题不在于 IEnumerable 或 IList 它是您呈现集合的方式你的看法.

the problem is not with the IEnumerable or the IList it the way you are rendering the collection in your view.

@for(var i = 0;i < Model.People.Count;i++)
{
    <tr>
        <td>@Html.TextBoxFor(m => Model.People[i].Name)</td>
        <td>@Html.TextBoxFor(m => Model.People[i].Age)</td>
    </tr>
}

请注意，对于每个列表项，您都附加了一个连续索引，这使模型绑定器能够发挥其魔力

Observe that with each list item you are appending a continuous index which enables the model binder to do its magic

好书

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