如何在 MVC3 中将嵌套的 ViewModel 从 View 绑定到 Controller? [英] How can I bind nested ViewModels from View to Controller in MVC3?

问题描述

我正在用 C# 开发一个 ASP.NET MVC 3 应用程序，我使用 Razor.我现在正在处理一个关于通过控制器通过视图传递/接收到视图的视图模型绑定对象的问题.让我们说清楚.我有以下 ViewModel:

I am developing an ASP.NET MVC 3 application in C# and I use Razor. I am now dealing with a problem concerning the binding of objects through ViewModels passed/received to/from the View by the Controller. Let's make it clear. I have the following ViewModels:

public class ContainerViewModel
{
   public int ContainerId {get; set;}
   public string ContainerName {get; set;}
   public List<ItemPostModel> ItemData {get; set;}
}

public class ItemPostModel
{ 
   public int ItemId {get; set;}
   public string ItemName {get; set;}
   public int ItemValue {get; set;}
}

ContainerViewModel 用于将数据传递给视图.它的属性 ContainerId 和 ContainerName 仅用于显示目的.List 属性必须使用 Form 填充.视图看起来像这样(它是一个简化版本):

The ContainerViewModel is used to pass the data to the View. Its properties ContainerId and ContainerName are used just for display purposes. The List<ItemPostModel> property has to be filled using a Form. The View looks something like this (it is a simplified version):

<strong>@Model.ContainerName</strong>


@using (Html.BeginForm()) 
{
    <fieldset>
    @foreach(var item in Model.ItemData)
    {
       @Html.TextBox(item.ItemId);
       @Html.TextBox(item.ItemName);
       @Html.TextBox(item.ItemValue);

       <p>
           <input type="submit" value="Save" />
       </p>
    }
    </fieldset>
}

Controller对应的动作方法如下:

public ActionResult UpdateItems()
{
   //fill in the ContainerViewModel lcontainer

   return View("UpdateItems", lcontainer);
}

[HttpPost]
public ActionResult UpdateItems(int containerId, ItemPostModel itemData)
{
   //store itemData into repository
}

问题在于，使用此代码，传递给 Post ActionMethod UpdateItems 的 ItemPostModel itemData 始终为空.containerId 已正确传递.如果我在控制器中使用以下代码，结果相同(显然不是 DRY)；

The problem is that with this code the ItemPostModel itemData passed to the Post ActionMethod UpdateItems is always empty. The containerId is correctly passed. Same result if I use the following code in the Controller (obviously not DRY);

[HttpPost]
public ActionResult UpdateItems(ContainerViewModel container)
{
   //extract itemData from ContainerViewModel container
   //store itemData into repository
}

我如何教导"应用程序我希望将表单元素存储在List?我应该修改 ModelBinder 还是有更简单的方法来执行此任务?谢谢大家的回答.

How can I "teach" the application that I want the form elements stored in the List<ItemPostModel>? Shall I modify the ModelBinder or there is a simpler way to perform this task? Thanks everybody for your answers.

推荐答案

不要在视图中编写循环.使用编辑器模板:

Don't write loops in a view. Use editor templates:

<strong>@Model.ContainerName</strong>
@using (Html.BeginForm()) 
{
    <fieldset>
        @Html.EditorFor(x => x.ItemData)
        <input type="submit" value="Save" />
    </fieldset>
}

在相应的编辑器模板(~/Views/Shared/EditorTemplates/ItemPostModel.cshtml)中:

and inside the corresponding editor template (~/Views/Shared/EditorTemplates/ItemPostModel.cshtml):

@model ItemPostModel
@Html.TextBox(x => x.ItemId)
@Html.TextBox(x => x.ItemName)
@Html.TextBox(x => x.ItemValue)

在控制器操作中，您可能需要指定前缀:

And in the controller action you might need to specify the prefix:

[HttpPost]
public ActionResult UpdateItems(
    int containerId, 
    [Bind(Prefix = "ItemData")]ItemPostModel itemData
)
{
   //store itemData into repository
}

这应该就是全部了.编辑器模板将负责为绑定生成正确的输入字段名称.

and that should be pretty much all. The editor template will take care of generating the proper input field names for the binding to work.

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