C# Visual Studio asp.net 将项目添加到列表属性

Question

我目前正在开展一个为自行车商店建模的项目。在我的“订单”对象中，我有一个 lis 对象用于订单上的 Bike 项目。我如何将自行车添加到此列表中？即我想在创建视图中显示可用自行车的列表，然后将其中一辆或多辆添加到订单中。

我的控制器：

        public ActionResult Create()
        {
            return View();
        }


        [HttpPost]
        [ValidateAntiForgeryToken]
        public ActionResult Create([Bind(Include = "OrderNumber,CustomerName,OrderDate,PickupDate,TotalCost,PaymentMethod")] Order order)
        {
            if (ModelState.IsValid)
            {
                db.Orders.Add(order);
                db.SaveChanges();
                return RedirectToAction("Index");
            }

            return View(order);
        }

我的库存模型

public class Inventory
    {
        public int Id { get; set; }

        public string SerialNumber { get; set; }

        public virtual Store Store { get; set; }
        public int? StoreId { get; set; }

        public string Model { get; set; }

        public string Description { get; set; }

        public Decimal InventoryCost { get; set; }

        public Decimal RecSalePrice { get; set; }

        public Decimal SalePrice { get; set; }

        public string PaymentMethod { get; set; }

        public virtual BikeCategory Category { get; set; }
        public int? CategoryId { get; set; }







    }       

我的订单型号：

namespace BikeStore.Models
{

    public class Order
    {
        public Order()
        {
            OrderedItems = new List<Inventory>();
        }

        public string CustomerName { get; set; } //FROM CONTROLLER User.Identity.Name

        public virtual List<Inventory> OrderedItems { get; set; }


         [Key, DatabaseGenerated(System.ComponentModel.DataAnnotations.Schema.DatabaseGeneratedOption.Identity)]
        public int OrderNumber { get; set; }

在订单的创建视图中：

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

    <div class="form-horizontal">
        <h4>Order</h4>
        <hr />
        @Html.ValidationSummary(true, "", new { @class = "text-danger" })
        <div class="form-group">
            @Html.LabelFor(model => model.CustomerName, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.EditorFor(model => model.CustomerName, new { htmlAttributes = new { @class = "form-control" } })
                @Html.ValidationMessageFor(model => model.CustomerName, "", new { @class = "text-danger" })
            </div>
        </div>

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


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

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

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

        <div class="form-group">
            <div class="col-md-offset-2 col-md-10">
                <input type="submit" value="Create" class="btn btn-default" />
            </div>
        </div>
    </div>
}

<div>
    @Html.ActionLink("Back to List", "Index")
</div>

Answer 1

首先创建视图模型来表示您想要在视图中显示/编辑的内容（根据需要添加显示和验证属性）

public class InventoryVM
{
  public int ID { get; set; }
  public string Name { get; set; }
  public bool IsSelected { get; set; }
}
public class OrderVM
{
  public string PaymentMethod { get; set; }
  public List<InventoryVM> Inventory { get; set; }
}

请注意，CustomerName、OrderDate 和 Total 是不合适的（您不希望用户编辑这些 - 应该在保存订单之前立即在 POST 方法中设置它们）。不确定PickupDate 代表什么，但如果它是实际日期，那么这也不合适（它会在收集订单时单独设置）。我还建议 PaymentMethod 是 PaymentType 的枚举或集合，并在视图中使用下拉列表进行选择。

那么GET方法就是

public ActionResult Create()
{
  // Get all available bikes, for example
  var inventory = db.Inventory;
  OrderVM model = new OrderVM
  {
    Inventory = inventory.Select(i => new
    {
      ID = i.ID,
      Name = i.Model // modify this to suit what you want to display in the view
    }).ToList()
  };
  return View(model);
}

在视图中

@model yourAssembly.OrderVM
@using (Html.BeginForm())
{
  for(int i = 0; i < Model.Inventory.Count; i++)
  {
    @Html.HiddenFor(m => m.Inventory[i].ID)
    @Html.CheckBoxFor(m => m.Inventory[i].IsSelected)
    @Html.LabelFor(m => m.Inventory[i].IsSelected, Model.Inventory[i].Name)
  }
  @Html.TextBoxFor(m => m.PayentMethod)
  <input type="submit" value="Create" />
}

POST 方法是

public ActionResult Create(OrderVM model)
{
  // Initialize a new Order and map properties from view model
  var order = new Order
  {
    CustomerName = User.Identity.Name,
    OrderDate = DateTime.Now,
    ....
    PaymentMethod = model.PaymentMethod
  }
  // Save the order so that you now have its `ID`
  IEnumerable<int> selectedItems = model.Inventory.Where(i => i.IsSelected).Select(i => i.ID);
  foreach(var item in selectedItems)
  {
    // You have not shown the model for this so just guessing
    var orderItem = new OrderItem{ OrderID = order.Id, InventoryId = item };
    db.OrderItems.Add(orderItem);
  }
  db.SaveChanges();
}

旁注：

1. 如果您希望能够允许用户选择多于一个 项目，你可以把bool IsSelected改成int Quantity
2. 如果您想显示有关项目的其他信息， 说Description 和Cost 你可以包含其他属性 在InventoryVM 视图模型中显示它们 @Html.DisplayFor(m => m.Inventory[i].Description)
3. 如果要显示所有选定项目的总成本 查看，您将需要使用 javascript/jquery
4. 如果ModelState 可能无效，您将需要重新填充 返回视图之前InventoryVM的属性（如图 只有ID 和IsSelected 属性回发）或​​包括 视图中其他属性的隐藏输入