将id从视图传递给控制器

Question

其实我是MVC的初学者.简单的问题:

例如,我有类别页面的ViewModel:

public class CategoryViewModel
{
    public int ProductId {get;set;}
    public int CategoryId {get;set;}
    public string ProductName {get;set;}
    public string CategoryName {get;set;}
}

在控制器中,我传递CategoryId和CategoryName到视图:

public ActionResult Index()
{
    CategoryViewModel categoryViewModel = new CategoryViewModel();
    categoryViewModel.CategoryId = catId; \\Get from DB
    categoryViewModel.CategoryName = catName; \\Get from DB

    return View("Category", categoryViewModel);
}

然后在视图上我需要将产品添加到此类别:

<form action=@Url.Action("AddProduct", "Category") method="POST" enctype = "multipart/form-data">
    <textarea name ="ProductName"></textarea>
    <input type="submit" value="Add"/>
</form>

在AddProduct的控制器中:

[HttPost]
public ActionResult AddPost(CategoryViewModel categoryViewModel)
{
    var productName = categoryViewModel.ProductName;
    var categoryId = ?
    ProductRepository.AddProductToCategory(productName, categoryId);

    return new EmptyResult();
}

问题:如何获得CategoryId？或许还有另一种方法？

Answer 1

更改视图以包含CategoryId属性的控件

@model CategoryViewModel
@using(Html.BeginForm("AddProduct", "Category"))
{
  @Html.HiddenFor(m => m.CategoryId)
  @Html.TextAreaFor(m => m.ProductName)
  <input type="submit" value="Add" />
}

注意,总是使用强类型html助手来生成你的html.