将复杂的ViewModel传递给MVC 3中的HttpPost方法

Question

我目前正在为我的项目编写一个Edit函数,我似乎无法使View Model正确,允许它从View传回Controller.视图模型的结构如下:

public class CreateUserViewModel : ICreateUserViewModel
{
    #region Properties
    public string UserName { get; set; }
    public string Password { get; set; }
    public string Email { get; set; }
    public string SelectedUserType { get; set; }
    public List<ICreateUserItemViewModel> UserTypes { get; set; }
    public List<ICreateUserItemViewModel> Products { get; set; }
    public List<ICreateUserItemViewModel> Languages { get; set; }
    #endregion

    #region Constructor
    public CreateUserViewModel()
    {
    }

    public CreateUserViewModel(List<Product> products, List<Language> languages)
    {
        Products = new List<ICreateUserItemViewModel>();
        foreach (var prod in products)
        {
            var prodVM = new CreateUserItemViewModel
            {
                Name = prod.Name,
                IsSelected = false,
                ID = (int)prod.ID
            };
            Products.Add(prodVM);
        }

        Languages = new List<ICreateUserItemViewModel>();
        foreach (var lang in languages)
        {
            var langVM = new CreateUserItemViewModel
            {
                Name = lang.Name,
                IsSelected = false,
                ID = (int)lang.ID
            };
            Languages.Add(langVM);
        }

    }
    #endregion
}

子类ViewModel CreateUserItemViewModel:

public class CreateUserItemViewModel : ICreateUserItemViewModel
{
    public string Name { get; set; }
    public int ID { get; set; }
    public bool IsSelected { get; set; }
}

我希望这个子类在视图中表示为一个复选框,因此用户可以选择是否包含它.

用户控制器:

[HttpPost]
public ActionResult Create(CreateUserViewModel model)
{
    if (ModelState.IsValid)
    {
        User newUser = new User();
        newUser.UserName = model.UserName;
        newUser.Password = model.Password;
        newUser.Email = model.Email;
        newUser.Products = model.Products; //Always NULL

当我在应用程序的这一部分上设置断点时,将填充用户名密码和电子邮件的属性,但产品和语言为空.我使用Fiddler2来观察传入控制器的内容,这是输出:

UserName=asdasdsdasd&Password=asd&Email=asD%40asd.com&type.IsSelected=Admin
&prod.ID=1&prod.IsSelected=true&prod.IsSelected=false
&prod.ID=2&prod.IsSelected=false
&prod.ID=3&prod.IsSelected=false
&prod.ID=4&prod.IsSelected=false
&lang.ID=1&lang.IsSelected=true&lang.IsSelected=false
&lang.ID=2&lang.IsSelected=true&lang.IsSelected=false
&lang.ID=3&lang.IsSelected=false
&lang.ID=4&lang.IsSelected=false
&lang.ID=5&lang.IsSelected=false
&lang.ID=6&lang.IsSelected=false
&lang.ID=7&lang.IsSelected=false
&lang.ID=8&lang.IsSelected=false
&lang.ID=9&lang.IsSelected=false
&lang.ID=10&lang.IsSelected=false
&lang.ID=11&lang.IsSelected=false
&lang.ID=12&lang.IsSelected=false
&lang.ID=13&lang.IsSelected=false
&lang.ID=14&lang.IsSelected=false
&lang.ID=15&lang.IsSelected=false
&lang.ID=16&lang.IsSelected=false
&lang.ID=17&lang.IsSelected=false
&lang.ID=18&lang.IsSelected=false
&lang.ID=19&lang.IsSelected=false

创建视图的代码块是:

<div class="editor-label">
    @Html.Label("User Products:")
</div>
<div class="editor-field">
    @foreach (var prod in Model.Products)
    {
        @Html.Label(prod.Name)
        @Html.HiddenFor(x => prod.ID)
        @Html.CheckBoxFor(x => prod.IsSelected, new { name = prod.Name })
    }
</div>
<div class="editor-label">
    @Html.Label("User Languages:")
</div>
<div class="editor-field">
    @foreach (var lang in Model.Languages)
    {
        @Html.Label(lang.Name)
        @Html.HiddenFor(x => lang.ID)
        @Html.CheckBoxFor(x => lang.IsSelected, new { name = lang.Name })
    }
</div>
<p>
    <input type="submit" value="Create" />
</p>

我已经在这方面工作了很长一段时间,我开始认为我想做的事情是不可能的.我希望它返回CreateUserViewModel完全填充用户选择的所有值,但我只是不知道如何实现这一点.

有任何想法吗？

Answer 1

使用for循环而不是foreach.

@for (int i=0; i < Model.Products.Count; i++)
{
    @Html.Label(prod.Name)
    @Html.HiddenFor(model => model.Products[i].ID)
    @Html.CheckBoxFor(model => model.Products[i].IsSelected, new { name = prod.Name })
}

您的属性表达式需要包含模型绑定器的足够信息,以确定如何将POST值绑定到模型.

您还可以尝试为其创建编辑器模板ICreateUserItemViewModel,然后将标记更改为以下内容.

@Html.EditorFor(model => model.Products)