将 ViewModel 属性从局部视图绑定到主视图

Question

我对 ASP.NET MVC 以及基本上所有与 Web 相关的东西都很陌生。对不起，如果这是 nooby，但我正在尝试这样做：

我有一个具有复杂属性的 ViewModel（在此处导航）：

public class Request
{
    public virtual BaseRequestData RequestData { get; set; }
}

BaseRequestData 是抽象的，但有几个继承自它的类，它们还有其他类似的属性：

public class AcceleratorRequestData : BaseRequestData
{
    [Display(Name="Downside amount")]
    [Range(-100,0,ErrorMessage = "Downside participation must be between 0 and -100")]
    [Required]
    public decimal PutNotional { get; set; }

    [Display(Name="Upside strike")]
    [Range(1, 2, ErrorMessage = "Upside strike must be between 100% and 200%")]
    public decimal CallPercentStrike { get; set; }

}

在我的主“创建”视图上，我绑定到我的请求模型，但我想通过用户从下拉列表中选择它的类型（例如，AcceleratorRequestData）为我的 BaseRequestData 创建一个部分视图。 我尝试过的 是使用一些 jQuery 来调用控制器并根据下拉菜单呈现部分视图。这是我的部分观点之一，它是一堆表单组：

 @model Synapse.Models.AcceleratorRequestData

@Html.ValidationSummary(true,"",new {@class = "text-danger"})
<div class="form-group">
    @Html.LabelFor(m => Model.PutNotional, new {@class = "control-label col-md-2"})
    <div class="col-md-10">
        @Html.EditorFor(model => model.PutNotional, new {htmlAttributes = new {@class = "form-control"}})
        @Html.ValidationMessageFor(model => model.PutNotional, "", new {@class = "text-danger"})
    </div>
</div>
<div class="form-group">
    @Html.LabelFor(m => Model.CallPercentStrike, new { @class = "control-label col-md-2" })
    <div class="col-md-10">
        @Html.EditorFor(model => model.CallPercentStrike, new { htmlAttributes = new { @class = "form-control" } })
        @Html.ValidationMessageFor(model => model.CallPercentStrike, "", new { @class = "text-danger" })
    </div>
</div>

在我的主视图中替换占位符 <div>：

@using (Html.BeginHorizontalForm())
{
    @Html.AntiForgeryToken()

    <hr/>
    @Html.ValidationSummary(true, "", new {@class = "text-danger"})
    <div id="accelRequestPh" style="display: none;"></div>

    <input type="submit" value="Create" class="btn btn-default" />

}

但是在这里我的验证属性和绑定失败（显然，因为我的 BaseRequestData 对象未绑定到我的 Request 对象的实例）。我怎样才能做到这一点？我应该使用编辑器模板吗？如果我这样做了，我的主视图模型如何知道它们？

Answer 1

将AcceleratorRequestData 添加到您的Request 类中：

    public class Request
{
    public virtual BaseRequestData RequestData { get; set; }
    public  AcceleratorRequestData acceleratorRequestData { get; set; }
}

然后更改局部视图的模型：

@model Synapse.Models.Request.AcceleratorRequestData

Answer 2

所以我放弃了渲染不同 html 元素的下拉菜单，而是将下拉菜单移至上一页，以便将具体的子类传递给视图。像这样：

我的下拉菜单调用这个控制器：

    /// <summary>
    /// Get the correct view depending on the dropdown
    /// </summary>
    /// <param name="productType"></param>
    /// <returns></returns>
    [HttpGet]
    public ActionResult Create(string productType)
    {
        Request request = new Request();
        switch (productType)
        {
            case "Accelerator":
                request.RequestData = new AcceleratorRequestData();
                request.ColloquialType = ColloquialType.Accelerator;
                return View(request);
            case "BarrierAccelerator":
                request.RequestData = new BarrierAcceleratorRequestData();
                request.ColloquialType = ColloquialType.BarrierAccelerator;
                return View(request);
            default:
                return RedirectToAction("Index", "Requests");
        }
    }

返回父视图：

@using (Html.BeginHorizontalForm())
{
    @Html.AntiForgeryToken()

    <hr/>
    @Html.ValidationSummary(true, "", new {@class = "text-danger"})
    @Html.EditorFor(x => x.RequestData)

    <input type="submit" value="Create" class="btn btn-default"/>
}

我在这里为我的每个 BaseRequestData 孩子使用编辑器模板。这是一个：

@model Synapse.Models.AcceleratorRequestData

@Html.Hidden("ModelType", Model.GetType())           
@Html.ValidationSummary(true,"",new {@class = "text-danger"})
<div class="form-group">
    @Html.LabelFor(m => Model.PutNotional, new {@class = "control-label col-md-2"})
    <div class="col-md-10">
        @Html.EditorFor(model => model.PutNotional, new {htmlAttributes = new {@class = "form-control"}})
        @Html.ValidationMessageFor(model => model.PutNotional, "", new {@class = "text-danger"})
    </div>
</div>
<div class="form-group">
    @Html.LabelFor(m => Model.CallPercentStrike, new { @class = "control-label col-md-2" })
    <div class="col-md-10">
        @Html.EditorFor(model => model.CallPercentStrike, new { htmlAttributes = new { @class = "form-control" } })
        @Html.ValidationMessageFor(model => model.CallPercentStrike, "", new { @class = "text-danger" })
    </div>
</div>

隐藏的 html 助手来自此链接：ViewModel with List<BaseClass> and editor templates

而且我还必须编辑我的 global.cs

 public class MvcApplication : HttpApplication
    {
        protected void Application_Start()
        {
            AreaRegistration.RegisterAllAreas();
            FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
            RouteConfig.RegisterRoutes(RouteTable.Routes);
            BundleConfig.RegisterBundles(BundleTable.Bundles);
            log4net.Config.XmlConfigurator.Configure(new FileInfo(Server.MapPath("~/Web.config")));
            ModelBinders.Binders.Add(typeof(BaseRequestData), new BaseRequestDataModelBinder());
        }
    }

    public class BaseRequestDataModelBinder : DefaultModelBinder
    {
        protected override object CreateModel(ControllerContext controllerContext, ModelBindingContext bindingContext, Type modelType)
        {
            ValueProviderResult typeValue = bindingContext.ValueProvider.GetValue(bindingContext.ModelName + ".ModelType");
            Type type = Type.GetType(
                (string)typeValue.ConvertTo(typeof(string)),
                true
            );
            object model = Activator.CreateInstance(type);
            bindingContext.ModelMetadata = ModelMetadataProviders.Current.GetMetadataForType(() => model, type);
            return model;
        }
    }

希望这对某人有所帮助！