asp.net-mvc - asp mvc 使用 View 模型在 View 中列出产品详细信息

Question

我正在尝试在 View 中列出单个产品详细信息。产品规范是动态变化的，因为规范是在表格中逐行添加的，这意味着我们可以为每个产品添加大量规范(就像在电子商务网站中所做的那样)。现在我可以使用 ViewBag 来满足要求，但我决定使用 ViewModel作为更好的做法。

模型类:

// Product:
public partial class ProductTable
{
    public ProductTable()
    {
        this.SpecificationsTable = new HashSet<SpecificationsTable>();
    }

    public int ProductID { get; set; }
    public string Title { get; set; }
    public string SmallDescription { get; set; }
    public string FullDescription { get; set; }

    public virtual ICollection<SpecificationsTable> SpecificationsTable { get; set; }
    }

//Specifications:
public partial class SpecificationsTable
{
    public int SpecificationsID { get; set; }
    public string SpecificationName { get; set; }
    public string SpecificationValue { get; set; }
    public Nullable<int> ProductID { get; set; }
    public virtual ProductTable ProductTable { get; set; }
}

View 模型:

public class DetailsViewModel
{
    public int ProductID { get; set; }
    public string Title { get; set; }
    public string SmallDescription { get; set; }
    public string FullDescription { get; set; }
    public string SpecificationName { get; set; }
    public string SpecificationValue { get; set; }
}

操作方法

public ActionResult ProductDetails(int id)
{
    var details = (from c in dbo.ProductTable
                   join s in dbo.SpecificationsTable 
                   on c.ProductID equals s.ProductID
                   where c.ProductID == id
                   select new DetailViewModel
                   {
                       Title = c.Title,
                       SmallDescription = c.SmallDescription,
                       FullDescription = c.FullDescription
                   }).ToList();

     // To remove repeated product title , small and full description
     var distinctItems = details.GroupBy(x => x.ProductID).Select(y => y.First());

     // To show product title, small and full description for this product

     ViewBag.ProductDetails = distinctItems;

     var specifications = (from c in dbo.ProductTable
                             join s in dbo.SpecificationsTable 
                             on c.ProductID equals s.ProductID
                             where c.ProductID == id
                             select new DetailViewModel
                             {
                                 SpecificationName = s.SpecificationName,
                                 SpecificationValue = s.SpecificationValue
                             }).ToList();

    // To show list of specifications for this product
    ViewBag.Specifcations = specifications;
    return View();
}

预期输出:

详情:

Title: New Samsung offer

SmallDescription : Something small 

FullDescription : Something full

规范:

Mobile Name :Samsung

Model : 2015

Price : 70 $

Color:  White

我正在使用数据库优先方法，我正在尝试学习如何在这里使用 View 模型。

Answer 1

您当前的 View 模型没有反射(reflect)您想要在 View 中显示的内容，这是每个产品的多个规范，因此您需要一个集合属性。将您的 View 模型更改为

public class SpecificationVM
{
  public string Name { get; set; }
  public string Value { get; set; }
}
public class ProductVM
{
  public string Title { get; set; }
  public string SmallDescription { get; set; }
  public string FullDescription { get; set; }
  IEnumerable<SpecificationVM> Specifications { get; set; }
}

然后在 Controller 中，使用填充您的 View 模型

public ActionResult ProductDetails(int id)
{
  var product = db.ProductTable.Where(p => p.ProductID == id).FirstOrDefault();
  // note you may need to add .Include("SpecificationsTable") in the above
  if (product == null)
  { 
    return new HttpNotFoundResult();
  }
  ProductVM model = new ProductVM()
  {
    Title = product.Title,
    SmallDescription = product.SmallDescription,
    FullDescription = product.FullDescription,
    Specifications = product.SpecificationsTable.Select(s => new SpecificationVM()
    {
      Name = s.SpecificationName,
      Value = s.SpecificationValue
    })
  };
  return View(model);
}

然后在 View 中

@model yourAssembly.ProductVM
<h2>Details</h2>
@Html.DisplayNameFor(m => m.Title)
@Html.DisplayFor(m => m.Title)
.... // ditto for SmallDescription and FullDescription 
<h2>Specifications</h2>
@foreach(var item in Model.Specifications)
{
  @Html.DisplayFor(m => item.Name)
  @Html.DisplayFor(m => item.Value)
}