ASP.NET MVC中一对多关系ViewModel的CRUD操作

Question

过去几天我一直在网上寻找，但仍然无法得到我想要的。也许是我的研究方式不对。但问题是我有一个订单型号

public class Order
{
[Key]
public int Id { get; set; }
public int TotalItems { get; set; }
public DateTime DeliveryDate { get; set; }
public string OrderNumber { get; set; }
public string DeliveryAddress { get; set; }
[ForeignKey("ClientId")]
public int ClientId { get; set; }

public int OrderItemId { get; set; }
[ForeignKey("OrderItemId")]
public List<OrderItem> OrderItems { get; set; }
public Client Client { get; set; }
}

和一个OrderItem模型

public class OrderItem
{
public int Id { get; set; }
[ForeignKey("OrderId")]
public int OrderId{ get; set; }
public int InventoryInfoId { get; set; }
[ForeignKey("InventoryInfoId")]
[Required]
public string ItemCode { get; set; }
public int Quantity { get; set; }
public virtual InventoryInfo InventoryInfo { get; set; }
public Order Order { get; set; }
}

根据用户输入，一个订单可以有多个OrderItems。这是我的OrderViewModel

public class OrderViewModel
{
//public int OrderId { get; set; }
//public string OrderNumber { get; set; }
//public string DeliveryAddress { get; set; }
//public int ClientId { get; set; }
//public DateTime Deliverydate { get; set; }
public Order Order { get; set; }
public IList<OrderItem> OrderItems { get; set; }
public int ItemCode { get; set; }
public int Quantity { get; set; }
}

这是我的Create.cshtml

<div class="row">
<div class="col-md-4">
<form asp-action="Create">
<div asp-validation-summary="All" class="text-danger"></div>
<div class="form-group">
<label asp-for="Order.ClientId" class="control-label"></label>
<select asp-for="Order.ClientId" class="form-control" asp-items="ViewBag.ClientId">
<option>-- Select Client --</option>
</select>
<span asp-validation-for="Order.ClientId" class="text-danger"></span>
</div>
<div class="form-group">
<label asp-for="Order.OrderNumber" class="control-label"></label>
<input asp-for="Order.OrderNumber" class="form-control" />
<span asp-validation-for="Order.OrderNumber" class="text-danger"></span>
</div>
<div class="form-group">
<label asp-for="Order.DeliveryDate" class="control-label"></label>
<input type="date" data-val="true" asp-for="Order.DeliveryDate" class="form-control" />
<span asp-validation-for="Order.DeliveryDate" class="text-danger"></span>
</div>
<div class="form-group">
<label asp-for="Order.DeliveryAddress" class="control-label"></label>
<input asp-for="Order.DeliveryAddress" class="form-control" />
<span asp-validation-for="Order.DeliveryAddress" class="text-danger"></span>
</div>
<table id="tblCustomers" class="table" cellpadding="0" cellspacing="0">
<thead>
<tr>
<th style="width:150px">Item Code</th>
<th style="width:150px">Quantity</th>
<th></th>
</tr>
</thead>
<tbody></tbody>
<tfoot id="item-list">
<tr>
<td>
<select asp-for="OrderItems[0].ItemCode" class="items" asp-items="@ViewBag.Item"></select>
</td>
<td><input type="text" asp-for="OrderItems[0].Quantity" class="items" /></td>
@*<td><input type="button" id="btnAdd" value="Add" /></td>*@
</tr>
</tfoot>
</table>
<button id="add">Add another item</button>
<div class="form-group">
<input type="submit" value="Create" class="btn btn-default" />
</div>
</form>
</div>
</div>

@section Scripts {
@{await Html.RenderPartialAsync("_ValidationScriptsPartial");}
<script>
$("#add").click(function (e) {
e.preventDefault();
var i = ($(".items").length) / 2;
var model = @Html.Raw(@ViewBag.Items);
var n = '<tr><td><select id="OrderItems_' + 1 + '_ItemCode" name="OrderItems[' + 1 + '].ItemCode" class="items" /></td>' +
'<td><input type="text" class="items" name="OrderItems[' + 1 + '].Quantity" /></td></tr>'
$("#item-list").append(n);
var Items = "";
$(model).each(function (e) {
Items = Items + '<option value="' + this.Value + '">' + this.Text + '</option>'
});
var subItemList = $("#OrderItems" + 1 + "_ItemCode");
subItemList.empty();
subItemList.append(Items);
});
</script>
}

用户有两个部分，订单详细信息和订单项目这是我的订单控制器创建

[HttpPost]
[ValidateAntiForgeryToken]
public async Task<IActionResult> Create([Bind("ClientId", "OrderNumber", "DeliveryDate", "DeliveryAddress")]OrderViewModel OrderVM)
{
try
{
if (ModelState.IsValid)
{
var order = new Order()
{
Id = OrderVM.OrderId,
DeliveryAddress = OrderVM.DeliveryAddress,
DeliveryDate = OrderVM.Deliverydate,
OrderNumber = OrderVM.OrderNumber
};
_context.Add(order);
await _context.SaveChangesAsync();
return RedirectToAction(nameof(Index));
}
}
catch (DbUpdateException ex)
{
//Log the error(uncomment ex variable name and write a log.
ModelState.AddModelError("", "Unable to save changes. " +
"Try again, and if the problem persists " +
"see your system administrator.");
}
PopulateClientDropDownList(OrderVM.ClientId);
CreateMultipleOrderItem();
return View(OrderVM);
}

事实上，我现在很失落，因为我已经尝试了几个教程和示例，但似乎没有什么能帮助我。也许我听不懂。伙计们，请帮帮我！

在杰弗瑞的帮助下。

[HttpPost]
[ValidateAntiForgeryToken]
public async Task<IActionResult> Create(OrderViewModel OrderVM)
{
try
{
if (ModelState.IsValid)
{
//var order = new Order()
//{
//    Id = OrderVM.OrderId,
//    DeliveryAddress = OrderVM.DeliveryAddress,
//    DeliveryDate = OrderVM.Deliverydate,
//    OrderNumber = OrderVM.OrderNumber
//};
_context.AddRange(OrderVM);

//_context.AddRange(OrderVM.OrderItems);
await _context.SaveChangesAsync();
return RedirectToAction(nameof(Index));
}
}
catch (DbUpdateException ex)
{
//Log the error(uncomment ex variable name and write a log.
ModelState.AddModelError("", "Unable to save changes. " +
"Try again, and if the problem persists " +
"see your system administrator.");
}
PopulateClientDropDownList(OrderVM.Order.ClientId);
CreateMultipleOrderItem();
return View(OrderVM);
}

控制器的编辑版本允许数据从我的视图页面传递到控制器。但是有一个错误。InvalidOperationException：未找到实体类型"OrderViewModel"。请确保已将实体类型添加到模型中。Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.GetOrCreateEntry(对象实体(

Answer 1

试试这样的

PD_8