【发布时间】：2016-10-28 23:59:04
【问题描述】：
我已经尝试了一段时间来填充一个列表框，但我似乎无法弄清楚。我已经非常广泛地研究了实体框架 7 文档，但我还是新手。目前还没有很多针对 MVC6/EF7 的教程，因此很难知道将一个实体类与另一个实体类关联的最佳实践是什么。请原谅问题的长度，我只是想彻底。
我正在使用实体框架 7、asp.net 5 和 MVC 6。
重现问题的步骤
- 创建一个新的 ASP.Net Web 应用程序 → 项目名称：ListBox.Web → 解决方案名称 ListBox
- 选择 APS.NET 5 模板 → Web 应用程序
-
在Models文件夹中创建两个类
父.cs
using System.Collections.Generic; using System.ComponentModel.DataAnnotations; namespace ListBox.Web.Models { public class Parent { public int ParentId { get; set; } [Required] public string Name { get; set; } public ICollection<Child> Children { get; set; } } }Child.cs
using System.ComponentModel.DataAnnotations; namespace ListBox.Web.Models { public class Child { public int ChildId { get; set; } [Required] public string Name { get; set; } public int ParentId { get; set; } public Parent Parent { get; set; } } } -
在
_Layout.cshtml中添加控制器链接<ul class="nav navbar-nav"> <li><a asp-controller="Home" asp-action="Index">Home</a></li> <li><a asp-controller="Parents" asp-action="Index">Parents</a></li> <li><a asp-controller="Children" asp-action="Index">Children</a></li> <li><a asp-controller="Home" asp-action="About">About</a></li> <li><a asp-controller="Home" asp-action="Contact">Contact</a></li> </ul> -
创建数据库
ListBox\src\ListBox.Web>dns ef migrations add Initial ListBox\src\ListBox.Web>dnx ef database update 运行网络应用程序
-
添加一对父母。
-
尝试添加一个孩子。
控制器源代码
using System.Linq;
using Microsoft.AspNet.Mvc;
using Microsoft.AspNet.Mvc.Rendering;
using Microsoft.Data.Entity;
using ListBox.Web.Models;
namespace ListBox.Web.Controllers
{
public class ChildrenController : Controller
{
private ApplicationDbContext _context;
public ChildrenController(ApplicationDbContext context)
{
_context = context;
}
// GET: Children
public IActionResult Index()
{
var applicationDbContext = _context.Child.Include(c => c.Parent);
return View(applicationDbContext.ToList());
}
// GET: Children/Details/5
public IActionResult Details(int? id)
{
if (id == null)
{
return HttpNotFound();
}
Child child = _context.Child.Single(m => m.ChildId == id);
if (child == null)
{
return HttpNotFound();
}
return View(child);
}
// GET: Children/Create
public IActionResult Create()
{
ViewData["ParentId"] = new SelectList(_context.Set<Parent>(), "ParentId", "Parent");
return View();
}
// POST: Children/Create
[HttpPost]
[ValidateAntiForgeryToken]
public IActionResult Create(Child child)
{
if (ModelState.IsValid)
{
_context.Child.Add(child);
_context.SaveChanges();
return RedirectToAction("Index");
}
ViewData["ParentId"] = new SelectList(_context.Set<Parent>(), "ParentId", "Parent", child.ParentId);
return View(child);
}
// GET: Children/Edit/5
public IActionResult Edit(int? id)
{
if (id == null)
{
return HttpNotFound();
}
Child child = _context.Child.Single(m => m.ChildId == id);
if (child == null)
{
return HttpNotFound();
}
ViewData["ParentId"] = new SelectList(_context.Set<Parent>(), "ParentId", "Parent", child.ParentId);
return View(child);
}
// POST: Children/Edit/5
[HttpPost]
[ValidateAntiForgeryToken]
public IActionResult Edit(Child child)
{
if (ModelState.IsValid)
{
_context.Update(child);
_context.SaveChanges();
return RedirectToAction("Index");
}
ViewData["ParentId"] = new SelectList(_context.Set<Parent>(), "ParentId", "Parent", child.ParentId);
return View(child);
}
// GET: Children/Delete/5
[ActionName("Delete")]
public IActionResult Delete(int? id)
{
if (id == null)
{
return HttpNotFound();
}
Child child = _context.Child.Single(m => m.ChildId == id);
if (child == null)
{
return HttpNotFound();
}
return View(child);
}
// POST: Children/Delete/5
[HttpPost, ActionName("Delete")]
[ValidateAntiForgeryToken]
public IActionResult DeleteConfirmed(int id)
{
Child child = _context.Child.Single(m => m.ChildId == id);
_context.Child.Remove(child);
_context.SaveChanges();
return RedirectToAction("Index");
}
}
}
子 Create.cshtml
@model ListBox.Web.Models.Child
@{
ViewData["Title"] = "Create";
}
<h2>Create</h2>
<form asp-action="Create">
<div class="form-horizontal">
<h4>Child</h4>
<hr />
<div asp-validation-summary="ValidationSummary.ModelOnly" class="text-danger"></div>
<div class="form-group">
<label asp-for="Name" class="col-md-2 control-label"></label>
<div class="col-md-10">
<input asp-for="Name" class="form-control" />
<span asp-validation-for="Name" class="text-danger" />
</div>
</div>
<div class="form-group">
<label asp-for="ParentId" class="col-md-2 control-label"></label>
<div class="col-md-10">
<select asp-for="ParentId" class ="form-control"></select>
</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>
</form>
<div>
<a asp-action="Index">Back to List</a>
</div>
@section Scripts {
<script src="~/lib/jquery/dist/jquery.min.js"></script>
<script src="~/lib/jquery-validation/dist/jquery.validate.min.js"></script>
<script src="~/lib/jquery-validation-unobtrusive/jquery.validate.unobtrusive.min.js"></script>
}
【问题讨论】：
标签： asp.net-core-mvc entity-framework-core asp.net-mvc-scaffolding