c# - 外键不起作用 | ASP .NET MVC 5 应用程序

Question

我正在尝试将发布到数据库的消息与发送该消息的相应 userId 连接起来。

但它不起作用，并返回错误:无法将 NULL 值插入表“aspnet-idelabs10-20160411101634.dbo.Ides”的列“UserId”中；列不允许为空。插入失败。该声明已终止。

这是非常符合逻辑的，因为它不能为空。

这是我的代码:

namespace idelabs10.Migrations
{
using System;
using System.Data.Entity.Migrations;

public partial class second : DbMigration
{
    public override void Up()
    {

        CreateTable(
           "dbo.Ides",
        c => new
        {
            IdeId = c.Int(nullable: false, identity: true),
            Emne = c.String(),
            Forslag = c.String(),
            UserId = c.String(nullable: false, maxLength: 128),
        })
           .PrimaryKey(t => t.IdeId)
           .ForeignKey("dbo.AspNetUsers", t => t.UserId, cascadeDelete: true)
           .Index(t => t.UserId);

        CreateTable(
            "dbo.AspNetRoles",
            c => new
                {
                Id = c.String(nullable: false, maxLength: 128),
                Name = c.String(nullable: false, maxLength: 256),
            })
            .PrimaryKey(t => t.Id)
            .Index(t => t.Name, unique: true, name: "RoleNameIndex");

        CreateTable(
            "dbo.AspNetUserRoles",
            c => new
            {
                UserId = c.String(nullable: false, maxLength: 128),
                RoleId = c.String(nullable: false, maxLength: 128),
            })
            .PrimaryKey(t => new { t.UserId, t.RoleId })
            .ForeignKey("dbo.AspNetRoles", t => t.RoleId, cascadeDelete: true)
            .ForeignKey("dbo.AspNetUsers", t => t.UserId, cascadeDelete: true)
            .Index(t => t.UserId)
            .Index(t => t.RoleId);

        CreateTable(
            "dbo.AspNetUsers",
            c => new
            {
                Id = c.String(nullable: false, maxLength: 128),
                Email = c.String(maxLength: 256),
                EmailConfirmed = c.Boolean(nullable: false),
                PasswordHash = c.String(),
                SecurityStamp = c.String(),
                PhoneNumber = c.String(),
                PhoneNumberConfirmed = c.Boolean(nullable: false),
                TwoFactorEnabled = c.Boolean(nullable: false),
                LockoutEndDateUtc = c.DateTime(),
                LockoutEnabled = c.Boolean(nullable: false),
                AccessFailedCount = c.Int(nullable: false),
                UserName = c.String(nullable: false, maxLength: 256),
            })
            .PrimaryKey(t => t.Id)
            .Index(t => t.UserName, unique: true, name: "UserNameIndex");

        CreateTable(
            "dbo.AspNetUserClaims",
            c => new
            {
                Id = c.Int(nullable: false, identity: true),
                UserId = c.String(nullable: false, maxLength: 128),
                ClaimType = c.String(),
                ClaimValue = c.String(),
            })
            .PrimaryKey(t => t.Id)
            .ForeignKey("dbo.AspNetUsers", t => t.UserId, cascadeDelete: true)
            .Index(t => t.UserId);

        CreateTable(
            "dbo.AspNetUserLogins",
            c => new
            {
                LoginProvider = c.String(nullable: false, maxLength: 128),
                ProviderKey = c.String(nullable: false, maxLength: 128),
                UserId = c.String(nullable: false, maxLength: 128),
            })
            .PrimaryKey(t => new { t.LoginProvider, t.ProviderKey, t.UserId })
            .ForeignKey("dbo.AspNetUsers", t => t.UserId, cascadeDelete: true)
            .Index(t => t.UserId);



    }

表“Ides”无法按照我想要的方式运行，因为它似乎无法从 aspnetuser 请求用户 ID。

有什么想法吗？顺便说一句，我对这个还很陌生:)

名为 Forslag2 的 Controller 的代码

using System;
using System.Collections.Generic;
using System.Data;
using System.Data.Entity;
using System.Linq;
using System.Net;
using System.Web;
using System.Web.Mvc;
using idelabs10.Models;

namespace idelabs10.Controllers
{
public class Forslag2Controller : Controller
{
    private ApplicationDbContext db = new ApplicationDbContext();

    // GET: Forslag2
    public ActionResult Index()
    {
        return View(db.Ides.ToList());
    }

    // GET: Forslag2/Details/5
    public ActionResult Details(int? id)
    {
        if (id == null)
        {
            return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
        }
        Ide ide = db.Ides.Find(id);
        if (ide == null)
        {
            return HttpNotFound();
        }
        return View(ide);
    }

    // GET: Forslag2/Create
    public ActionResult Create()
    {
        return View();
    }

    // POST: Forslag2/Create
    // To protect from overposting attacks, please enable the specific properties you want to bind to, for 
    // more details see http://go.microsoft.com/fwlink/?LinkId=317598.
    [HttpPost]
    [ValidateAntiForgeryToken]
    public ActionResult Create([Bind(Include = "IdeId,Emne,Forslag,UserId")] Ide ide)
    {
        if (ModelState.IsValid)
        {
            db.Ides.Add(ide);
            db.SaveChanges();
            return RedirectToAction("Index");
        }

        return View(ide);
    }

    // GET: Forslag2/Edit/5
    public ActionResult Edit(int? id)
    {
        if (id == null)
        {
            return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
        }
        Ide ide = db.Ides.Find(id);
        if (ide == null)
        {
            return HttpNotFound();
        }
        return View(ide);
    }

    // POST: Forslag2/Edit/5
    // To protect from overposting attacks, please enable the specific properties you want to bind to, for 
    // more details see http://go.microsoft.com/fwlink/?LinkId=317598.
    [HttpPost]
    [ValidateAntiForgeryToken]
    public ActionResult Edit([Bind(Include = "IdeId,Emne,Forslag,UserId")] Ide ide)
    {
        if (ModelState.IsValid)
        {
            db.Entry(ide).State = EntityState.Modified;
            db.SaveChanges();
            return RedirectToAction("Index");
        }
        return View(ide);
    }

    // GET: Forslag2/Delete/5
    public ActionResult Delete(int? id)
    {
        if (id == null)
        {
            return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
        }
        Ide ide = db.Ides.Find(id);
        if (ide == null)
        {
            return HttpNotFound();
        }
        return View(ide);
    }

    // POST: Forslag2/Delete/5
    [HttpPost, ActionName("Delete")]
    [ValidateAntiForgeryToken]
    public ActionResult DeleteConfirmed(int id)
    {
        Ide ide = db.Ides.Find(id);
        db.Ides.Remove(ide);
        db.SaveChanges();
        return RedirectToAction("Index");
    }

    protected override void Dispose(bool disposing)
    {
        if (disposing)
        {
            db.Dispose();
        }
        base.Dispose(disposing);
    }
}
}

Answer 1

首先，您需要激活该操作的授权，以便仅允许登录的帖子。如果您使用标准 MVC 应用程序，则非常简单，只需将“Authorize”属性添加到方法中即可。接下来，从环境中获取 UserId 并将其用于插入，请参见下面的示例(我从传入成员中删除了 UserId 以避免混淆):

[HttpPost]
[ValidateAntiForgeryToken]
[Authorize]
public ActionResult Create([Bind(Include = "IdeId,Emne,Forslag")] Ide ide)
{
    if (ModelState.IsValid)
    {
        ide.UserId = User.Identity.GetUserId()
        db.Ides.Add(ide);
        db.SaveChanges();
        return RedirectToAction("Index");
    }

    return View(ide);
}