我列出了一系列项目，我希望顶部工具有一个选项，你点击它并为它添加一个子对象，让我解释一下：
public class SupportItem
{
[Display(Name = "Categoría")]
[ConcurrencyCheck, Required]
public string Type { get; set; }
[Key, HiddenInput(DisplayValue = false)]
public int SupportItemId { get; set; }
[Display(Name = "Nombre")]
[ConcurrencyCheck,Required]
public string Name { get; set; }
[ConcurrencyCheck]
[Display(Name = "Descripción Corta")]
[DataType(DataType.MultilineText)]
[Required]
public string Description { get; set; }
[HiddenInput(DisplayValue = false)]
public virtual SupportItem Father { get; set; }
[Display(Name = "Descripción detallada")]
[DataType(DataType.MultilineText)]
[Required]
public string LongDescription { get; set; }
[HiddenInput(DisplayValue = false)]
public bool Children { get; set; }
}
现在你可以看到，这个实体有一个类型为SupporItem的父。现在我要做的就是列出所有内容并添加一个选项，让您轻松为您选择的项添加一个子项，继承视图定义：
@model IEnumerable<Domain.Entities.SupportItem>
@{
ViewBag.Title = "IndexSupportItems";
Layout = "~/Views/Shared/_AdminLayout.cshtml";
}
<h2>Index Support Items</h2>
<p>
@Html.ActionLink("Crear nuevo item principal", "Create")
</p>
<table class="Grid">
<tr>
<th>
Tipo
</th>
<th>
Nombre
</th>
<th>
Descripción
</th>
<th>
Acciones
</th>
</tr>
@foreach (var item in Model)
{
<tr>
<td>@item.Type</td>
@if(item.Children)
{
<td>@Html.ActionLink(item.Name,"ListChildren", new{item.SupportItemId})</td>
}
else
{<td>@item.Name</td>
}
<td>@item.Description</td>
<td>
@Html.ActionLink("Delete","DeleteSupportItem", new{item.Father.SupportItemId})<br />
@Html.ActionLink("Add subitem sub-item","AddSubitem", new{item.SupportItemId})<br />
@Html.ActionLink("Edit","EditSupportItem", new{item.SupportItemId})
</td>
</tr>
}
</table>
现在您可以看到，执行此操作的操作链接指向名为AddSubitem的方法，该方法实现如下：
public ViewResult AddSubitem(int supportItemId)
{
SupportItem child = new SupportItem() { Father = repo.GetSupportItemFromId(supportItemId) };
return View(child);
}
正如您所看到的，我收到了一个supportItemId，它是来自父权限（我想要添加新子项的那个）的id，在我的数据库上下文中找到它并创建新对象并指向Father对象我刚刚发现。完成后，返回的视图是：
@model Domain.Entities.SupportItem
@{
ViewBag.Title = "AddSubitem";
}
<h2>AddSubitem</h2>
@using (Html.BeginForm()) {
@Html.ValidationSummary(true)
<fieldset>
<legend>Support Item</legend>
<div class="editor-label">
@Html.LabelFor(model => model.Type)
</div>
<div class="editor-field">
@Html.EditorFor(model => model.Type)
@Html.ValidationMessageFor(model => model.Type)
</div>
<div class="editor-label">
@Html.LabelFor(model => model.Name)
</div>
<div class="editor-field">
@Html.EditorFor(model => model.Name)
@Html.ValidationMessageFor(model => model.Name)
</div>
<div class="editor-label">
@Html.LabelFor(model => model.Description)
</div>
<div class="editor-field">
@Html.EditorFor(model => model.Description)
@Html.ValidationMessageFor(model => model.Description)
</div>
<div class="editor-label">
@Html.LabelFor(model => model.LongDescription)
</div>
<div class="editor-field">
@Html.EditorFor(model => model.LongDescription)
@Html.ValidationMessageFor(model => model.LongDescription)
</div>
<p>
<input type="submit" value="Create" />
</p>
</fieldset>
}
<div>
@Html.ActionLink("Back to List", "Index")
</div>
@section Scripts {
@Scripts.Render("~/bundles/jqueryval")
}
在这个视图中，用户将设置一些变量，如名称和描述，然后提交对象，以便我可以将它持久保存到数据库，问题是我从中得到的对象view将其父亲id作为自己的id，并且Father属性为null，因此我最终更新了我想用此方法添加子对象的父对象：
public bool SaveSupportItem（SupportItem supportItem） { bool retorno = false;
if (supportItem.SupportItemId == 0)
{
context.SupportItems.Add(supportItem);
supportItem.Father.Children = true;
retorno = true;
}
else
{
SupportItem itemDB = context.SupportItems.Find(supportItem.SupportItemId);
if (itemDB != null)
{
itemDB.Name = supportItem.Name;
itemDB.Type = supportItem.Type;
itemDB.LongDescription = supportItem.LongDescription;
itemDB.Description = supportItem.Description;
retorno = true;
}
}
context.SaveChanges();
return retorno;
}
我在这里做错了什么？为什么我不能创建一个新对象？
感谢您花时间阅读本文，我们将非常感谢您的帮助！
答案 0 :(得分：0)
好吧，试试这个：
将此添加到您的SupportItem类
public class SupportItem
{
[Key]
[HiddenInput(DisplayValue = false)]
[ForeignKey("Father"), DatabaseGenerated(DatabaseGeneratedOption.None)]
public int SupportItemId { get; set; }
public virtual Father Father { get; set; }
...................
...................
}
然后改变：
@Html.ActionLink("Add subitem sub-item","AddSubitem", new{item.SupportItemId})<br />
到
@Html.ActionLink("Add subitem sub-item","AddSubitem", "Controller Name here" new{SupportItemId = @Model.FatherId})<br />
另外因为我们需要在这里new{SupportItemId = @Model.FatherId}，所以ActionLink需要在父亲的详细信息中，例如在父亲的详细信息中，只有单个父亲是当前的，或者你需要将supportItem与特定的父亲。
假设您使用的是ViewModel：
，您的控制器可能如下所示 [HttpGet]
public ActionResult CreateSuppo(int supportItemId)
{
var model = new CreateSupportItemViewModel ();
model.SupportItemId= supportItemId;
return View(model);
}
[HttpPost]
public ActionResult Create(CreateSupportItemViewModel viewModel)
{
if(ModelState.IsValid)
{
var father= db.Fathers.Single(f => f.FatherId == viewModel.SupportItemId);
var supportItem= new SupportItem();
supportItem.Name = viewModel.Name;
....................
.................
father.SupportItems.Add(supportItem);
db.SaveChanges();
}
return View(viewModel);
}