包含模型列表的模型 (MVC-3，Razor)

Question

包含模型列表的模型 (MVC-3，Razor)

29

这个问题困扰我已经两天了。有一些类似的帖子，但没有一个完全解决我的问题。

使用MVC-3，Razor语法：

-- EDIT.cshtml --

@using (Html.BeginForm("Edit", "My", FormMethod.Post, new { enctype = "multipart/form-data" }))
{
    <!-- Some fields... -->
    <div class="editor-field">
        @Html.TextAreaFor(m => m.LongDescription)
        @Html.ValidationMessageFor(m => m.LongDescription)
    </div>

    <!-- Some more fields work... Including picture upload (summary).-->
    <input name="button" type="submit" value="Add Picture" />

    <!-- Picture Item display -->
    @foreach(var thumbnail in Model.ThumbnailImagePathAndNames) 
    {
      <img src="@Url.Content(@thumbnail.ThumbnailPicturePath)" alt="" width="200" />
      @Html.RadioButtonFor(o=>o.SelectedImage, @thumbnail.ImageGUID)  Primary Picture 
      <!-- Checkbox to mark for deletion -->
      @Html.CheckBoxFor(o=>thumbnail.Delete) Delete ???????? <!---- Here is a problem - I don't understand how this should work -->
    }
    <input id="Submit1" name="button" type="submit" value="Complete Edit!" />
}

-- 我的控制器.cs --

 [HttpPost]
 public ActionResult Edit(String button, HttpPostedFileBase file, MyMainModel model)
 {
     // if button = submit picture,  work with picture here and break(long story)

     // save model data
         // if valid, save and redirect


     // not valid or error, load up view like normal but with error messages
     model.LoadThumbnails();
     return View(model);

 }

-- MyMainModel.cs --

public class MyMainModel
{
    // some properties...
     public Guid? SelectedImage { get; set; }

    [Display(Name = "Detailed Description")]
    public String LongDescription { get; set; }

    // some more properties....


    // and finally my list of models
    public IList<ThumbnailModel> ThumbnailImagePathAndNames { get; set; }

    public void LoadThumbnails()
    {
         // load up initial thumbnail models
         this.ThumbnailImagePathAndNames = new List<ThumbnailModel>(readDataService.GetThumbnailModels(this.SomeID));
    }
}

-- 缩略图模型.cs --

public class ThumbnailModel
{
    public Guid ImageGUID { get; set; }
    public String FullSizePicturePath { get; set; }
    public String ThumbnailPicturePath { get; set; }

    public bool Delete { get; set; }
}

那么问题出在哪里呢？当按下“Complete Edit!”按钮时，MyController的Edit被调用，如预期地保留了所有MyMainModel的数据……除了ThumbnailModel列表 - 它们变成了null。

应该如何解决这个问题？我尝试了许多不同的方法，包括制作可编辑模板和使用EditFor(o=>...，但都没有成功（这变得很困惑，因为我不知道EditFor是针对整个集合还是仅针对集合中的单个项 - 我两种方式都尝试了）。所有这些方法在添加复选框以进行删除时仍然有效，因此需要检索ThumbnailModels列表以检查内部Delete属性值。

感谢您的阅读和尝试理解。

[免责声明 - 一些变量和方法名称已更改以保护无辜程序。许多代码已被剥离并替换为注释代码。]

- Rob

那不应该是 thumbnail=>thumbnail.Delete 吗？ - Buildstarted

1个回答

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- Darin Dimitrov · Accepted Answer

这里有一个我准备好的示例来说明一些概念：

模型：

public class MyMainModel
{
    public Guid? SelectedImage { get; set; }
    public string LongDescription { get; set; }

    public IEnumerable<ThumbnailModel> ThumbnailImagePathAndNames { get; set; }

    public HttpPostedFileBase File { get; set; }
}

public class ThumbnailModel
{
    public Guid ImageGUID { get; set; }
    public bool Delete { get; set; }
}

控制器：

public class HomeController : Controller
{
    public ActionResult Index()
    {
        var model = new MyMainModel
        {
            // TODO: fetch from the repository instead of hardcoding
            ThumbnailImagePathAndNames = new[] 
            {
                new ThumbnailModel { ImageGUID = Guid.NewGuid() },
                new ThumbnailModel { ImageGUID = Guid.NewGuid() },
                new ThumbnailModel { ImageGUID = Guid.NewGuid() },
            }
        };
        return View(model);
    }

    [HttpPost]
    public ActionResult Index(MyMainModel model) 
    {
        ... the model will be properly bound here
    }
}

视图：

@model AppName.Models.MyMainModel
@{
    ViewBag.Title = "Index";
    Layout = "~/Views/Shared/_Layout.cshtml";
}
@using (Html.BeginForm("index", "home", FormMethod.Post, new { enctype = "multipart/form-data" }))
{
    <div class="editor-field">
        @Html.TextAreaFor(m => m.LongDescription)
        @Html.ValidationMessageFor(m => m.LongDescription)
    </div>
    <input type="file" name="file" />
    <!-- Use different names for the upload and complete submit
         buttons so that you can distinguish which one was clicked
         in the POST action 
    -->
    <input name="upload" type="submit" value="Add Picture" />

    @Html.EditorFor(x => x.ThumbnailImagePathAndNames)    
    <input name="complete" type="submit" value="Complete Edit!" />
}

编辑器模板: (~/Views/Home/EditorTemplates/ThumbnailModel.cshtml):

@model AppName.Models.ThumbnailModel
<!-- Pass the image id as hidden field -->
@Html.HiddenFor(x => x.ImageGUID)
@Html.CheckBoxFor(x => x.Delete)