如何将视图重定向到主页 - ASP.NET Core MVC

Question

这是我的第一个 ASP.NET 核心 MVC 项目，也是我的第一个 C# 体验。我正在创建一个模仿 ubereats/doordash.

的网络应用程序

现在，我正在编写 register/login 系统并将其与 SQL 数据库合并。 register/create 帐户功能运行良好，但现在我需要弄清楚如何在某人登录时对其进行身份验证。

所以，我写算法的方式是：

用户创建帐户 - 数据库已更新（运行良好）。
用户点击登录超链接 - 将他们带到登录页面（同样有效）
用户输入电子邮件和密码并按下提交（我在这里没有收到任何错误，但我认为我没有正确创建 form/authenticated）。
控制器获取用户输入的电子邮件和密码 - 如果数据库找到电子邮件，则检查密码是否正确。
如果正确 - 将用户重定向到主页，否则刷新并再次显示登录表单。

我需要帮助来检查和检索数据库中的项目，然后验证它们是否正确。

如果登录成功，我还需要帮助将用户重定向到主页（位于视图中的“主页”文件夹内）。 C# 和 asp.net 似乎非常先进，所以我想知道是否有一个我不知道的简单函数可能有用。

有人可以帮助我让登录部分正常工作吗？

登录控制器的这个特定部分是我认为的问题：

// GET: Logins/Create
public IActionResult LoginPortal()
{
    return View();
}

[HttpPost]
public async Task<IActionResult> LoginPortal(int id)
{
        var movie = await _context.Login.FindAsync(id);

        if (movie == null)
        {
            return View();
        }

        return View("Home/Index");
}

这是我目前的情况：

LoginsController.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc;                             //including necessary directories 
using Microsoft.AspNetCore.Mvc.Rendering;
using Microsoft.EntityFrameworkCore;
using EasyEats.Data;
using EasyEats.Models;

namespace EasyEats.Controllers
{
    public class LoginsController : Controller                      //log-in & register controller 
    {
        private readonly EasyEatsContext _context;

        public LoginsController(EasyEatsContext context)
        {
            _context = context;
        }

        // GET: Logins
        public async Task<IActionResult> Index()
        {
            return View(await _context.Login.ToListAsync());
        }

        // GET: Logins/Details/5
        public async Task<IActionResult> Details(int? id)
        {
            if (id == null)
            {
                return NotFound();
            }

            var login = await _context.Login
                .FirstOrDefaultAsync(m => m.ID == id);
            if (login == null)
            {
                return NotFound();
            }

            return View(login);
        }

        // GET: Logins/Create
        public IActionResult Create()
        {
            return View();
        }

        // POST: Logins/Create
        // To protect from overposting attacks, enable the specific properties you want to bind to, for 
        // more details, see http://go.microsoft.com/fwlink/?LinkId=317598.
        [HttpPost]
        [ValidateAntiForgeryToken]
        public async Task<IActionResult> Create([Bind("ID,FirstName,LastName,Address,Email,PhoneNumber,Password")] Login login)
        {
            if (ModelState.IsValid)
            {
                _context.Add(login);
                await _context.SaveChangesAsync();
                return RedirectToAction(nameof(Index));
            }
            return View(login);
        }


        // GET: Logins/Create
        public IActionResult LoginPortal()
        {
            return View();
        }

        [HttpPost]
        public async Task<IActionResult> LoginPortal(int id)
        {
            var movie = await _context.Login.FindAsync(id);

            if (movie == null)
            {
                return View();
            }

            return View("Home/Index");
        }

        // POST: Logins/Edit/5
        // To protect from overposting attacks, enable the specific properties you want to bind to, for 
        // more details, see http://go.microsoft.com/fwlink/?LinkId=317598.
        [HttpPost]
        [ValidateAntiForgeryToken]
        public async Task<IActionResult> Edit(int id, [Bind("ID,FirstName,LastName,Address,Email,PhoneNumber,Password")] Login login)
        {
            if (id != login.ID)
            {
                return NotFound();
            }

            if (ModelState.IsValid)
            {
                try
                {
                    _context.Update(login);
                    await _context.SaveChangesAsync();
                }
                catch (DbUpdateConcurrencyException)
                {
                    if (!LoginExists(login.ID))
                    {
                        return NotFound();
                    }
                    else
                    {
                        throw;
                    }
                }
                return RedirectToAction(nameof(Index));
            }
            return View(login);
        }

        // GET: Logins/Delete/5
        public async Task<IActionResult> Delete(int? id)
        {
            if (id == null)
            {
                return NotFound();
            }

            var login = await _context.Login
                .FirstOrDefaultAsync(m => m.ID == id);
            if (login == null)
            {
                return NotFound();
            }

            return View(login);
        }

        // POST: Logins/Delete/5
        [HttpPost, ActionName("Delete")]
        [ValidateAntiForgeryToken]
        public async Task<IActionResult> DeleteConfirmed(int id)
        {
            var login = await _context.Login.FindAsync(id);
            _context.Login.Remove(login);
            await _context.SaveChangesAsync();
            return RedirectToAction(nameof(Index));
        }

        private bool LoginExists(int id)
        {
            return _context.Login.Any(e => e.ID == id);
        }
    }
}

Login.cs（型号）

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;

namespace EasyEats.Models
{
    public class Login                      //class for customer log-in & registration information 
    {
        public int ID { get; set; }

        [Required]
        [Display(Name = "First Name")]
        public string FirstName { get; set; }

        [Required]
        [Display(Name = "Last Name")]
        public string LastName { get; set; }

        [Required]
        public string Address { get; set; }

        [Required]
        public string Email { get; set; }

        [Required]
        [Display(Name = "Phone Number")]
        public int PhoneNumber { get; set; }

        [Required]
        public string Password { get; set; }
    }
}

在我的“Views”文件夹中：我有一个 Home 文件夹、Logins 文件夹和 Shared 文件夹

Index.cshtml（在 Views 的“Home”文件夹内）

@{
    ViewData["Title"] = "Home Page";
}

<div class="text-center">
    <h1 class="display-4">Welcome</h1>
    <p>Learn about <a href="https://docs.microsoft.com/aspnet/core">building Web apps with ASP.NET Core</a>.</p>
</div>

LoginPortal.cshtml（在视图的“登录”文件夹内）

@model EasyEats.Models.Login

@{
    ViewData["Title"] = "Create";
}

<hr />
<div class="row">
    <div class="col-md-4">
        <form asp-action="LoginPortal">
            <div asp-validation-summary="ModelOnly" class="text-danger"></div>
            <div class="form-group">
                <label asp-for="Email" class="control-label"></label>
                <input asp-for="Email" class="form-control" />
                <span asp-validation-for="Email" class="text-danger"></span>
            </div>
            <div class="form-group">
                <label asp-for="Password" class="control-label"></label>
                <input asp-for="Password" class="form-control" />
                <span asp-validation-for="Password" class="text-danger"></span>
            </div>
            <div class="form-group">
                <input type="submit" value="Log in" class="btn btn-primary" />
            </div>
        </form>
    </div>
</div>

@section Scripts {
    @{await Html.RenderPartialAsync("_ValidationScriptsPartial");}
}

_Layout.cshtml（共享文件夹内）

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>@ViewData["Title"] - EasyEats</title>
    <link rel="stylesheet" href="~/lib/bootstrap/dist/css/bootstrap.min.css" />
    <link rel="stylesheet" href="~/css/site.css" />
</head>
<body>
    <header>
        <nav class="navbar navbar-expand-sm navbar-toggleable-sm navbar-light bg-white border-bottom box-shadow mb-3">
            <div class="container">
                <a class="navbar-brand" asp-area="" asp-controller="Home" asp-action="Index">EasyEats</a>
                <button class="navbar-toggler" type="button" data-toggle="collapse" data-target=".navbar-collapse" aria-controls="navbarSupportedContent"
                        aria-expanded="false" aria-label="Toggle navigation">
                    <span class="navbar-toggler-icon"></span>
                </button>
                <div class="navbar-collapse collapse d-sm-inline-flex flex-sm-row-reverse">
                    <partial name="_LoginPartial" />
                    <ul class="navbar-nav flex-grow-1">
                        <li class="nav-item">
                            <a class="nav-link text-dark" asp-area="" asp-controller="Home" asp-action="Index">Home</a>
                        </li>
                    </ul>
                </div>
            </div>
        </nav>
    </header>
    <div class="container">
        <main role="main" class="pb-3">
            @RenderBody()
        </main>
    </div>

    <footer class="border-top footer text-muted">
        <div class="container">
            &copy; 2020 - EasyEats - <a asp-area="" asp-controller="Home" asp-action="Privacy">Privacy</a>
        </div>
    </footer>
    <script src="~/lib/jquery/dist/jquery.min.js"></script>
    <script src="~/lib/bootstrap/dist/js/bootstrap.bundle.min.js"></script>
    <script src="~/js/site.js" asp-append-version="true"></script>
    @RenderSection("Scripts", required: false)
</body>
</html>

_LoginPartial.cshtml（共享文件夹内）

<ul class="navbar-nav">
    <li class="nav-item">
        <a class="nav-link text-dark" asp-controller="Logins"
           asp-action="Create">Register</a>
    </li>
    <li class="nav-item">
        <a class="nav-link text-dark" asp-controller="Logins"
           asp-action="LoginPortal">Login</a>
    </li>
</ul>

以下是一些图片： Homepage

Create Account page Login Page

Answer 1

I need help going through and retrieving items in the database and then verifying if they are correct.

您可以在数据库中找到该模型，其电子邮件与您从 form.Then 发布的电子邮件相同，请检查您找到的模型的密码。

I also need help redirecting the user to the homepage (which is inside of the "Home" folder in views) if the login is successful.

你可以使用 return RedirectToAction("Index", "Home");.

这是一个工作演示：

控制器：

public IActionResult LoginPortal()
{
    return View();
}

[HttpPost]
public async Task<IActionResult> LoginPortal(Login login)
{
    //for easy testing,i just hardcode the list
    var list = new List<Login>() {
    new Login(){Email="a",Password="123"},
    new Login(){Email="b",Password="111"}
    };
    //you could find it in the database
    //var movie = _context.Login.Where(a => a.Email == login.Email).FirstOrDefault();

    var movie = list.Where(a => a.Email == login.Email).FirstOrDefault();
    if (movie == null)
    {
        return View(login);
    }
    if (movie.Password==login.Password)
    {
        return RedirectToAction("Index", "Home");
    }
    return View();
}

结果：

更新：

您可以像下面这样设置 ModelState 错误：

[HttpPost]
public async Task<IActionResult> LoginPortal(Login login)
{
    //...
    if (movie == null)
    {
        ModelState.AddModelError("Email", "Do not find such email");
        return View(login);
    }
    if (movie.Password==login.Password)
    {
        return RedirectToAction("Index", "Home");
    }
    ModelState.AddModelError(string.Empty, "invalid login attempt");
    return View();
}

如何将视图重定向到主页 - ASP.NET Core MVC

How to redirect view to homepage - ASP.NET Core MVC

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c#

model-view-controller

asp.net-mvc

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