ASP.Net MVC - 关联对象的下拉列表 [英] ASP.Net MVC - dropdown list for associated objects

问题描述

在我的应用程序中有两个模型： Product 和 ProductType 。 产品引用 ProductType （在DB中，它被命名为 ProductTypeId ），而 ProductType 有两列（ Id 和名称）。

我可以使用以下代码获得正确填充和显示在论坛上的下拉列表：

控制器：

  var typeList = new SelectList（_entities.ProductType.ToList（），Id，Name）; 
 ViewData [Types] = typeList; 
  

查看：

 code><％= Html.DropDownList（ProductType，（IEnumerable< SelectListItem>）ViewData [Types]）％> 
  

然而，我的问题就是它不会在Controller中更新模型。如果我离开代码，那么ModelState是无效的，因为视图中的 ProductType 字符串，但是，如果我把它改为其他任何东西，似乎我不能更长的时间是指控制器内的。

解决方案

我刚刚尝试了相同的东西，它对我很好>

控制器：

  public ActionResult Create（）
 {
 configuredatorDataContext dc = new configuratorDataContext（）; 
 SelectList typelist = new SelectList（dc.Product_types.ToList（），id，Name）; 
 ViewData [Product_Types] =类型列表; 
 ViewData.Model = new Product（）; 
 return View（）; 
} 
 
 [AcceptVerbs（HttpVerbs.Post）] 
 public ActionResult Create（Product createProduct）
 {
 // createProduct here包含正确的type_id wich 
} 
  

查看：

 <％= Html.DropDownList（type_id，（IEnumerable< SelectListItem>）ViewData [Product_Types]）％> 
  

I have two models in my application: Product and ProductType. Product has a reference to ProductType (in the DB it's named ProductTypeId), while ProductType has two columns (Id and Name).

I can get the dropdown to be properly populated and displayed on the forum using the following code:

Controller:

var typeList = new SelectList(_entities.ProductType.ToList(), "Id", "Name");
ViewData["Types"] = typeList; 

View:

<%= Html.DropDownList("ProductType", (IEnumerable<SelectListItem>) ViewData["Types"]) %>

However my problem becomes that it's not updating the model back in the Controller. If I leave the code as is, then the ModelState is invalid because of the ProductType string in the view, However, if I change it to anything else, it seems I can no longer refer to it within the controller.

解决方案

I just tried the very same thing and it worked for me just fine

controller:

 public ActionResult Create()
    {
    configuratorDataContext dc = new configuratorDataContext();
    SelectList typelist = new SelectList(dc.Product_types.ToList(), "id", "Name");
    ViewData["Product_Types"] = typelist;
    ViewData.Model = new Product(); 
    return View();
    } 

    [AcceptVerbs(HttpVerbs.Post)]
    public ActionResult Create(Product createProduct)
    {
    // createProduct here contains correct type_id wich 
    }

view:

  <%= Html.DropDownList("type_id", (IEnumerable<SelectListItem>) ViewData["Product_Types"])%>

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