导航、剃刀视图、控制器的 ASP.NET 问题

Question

我正在为学校开发一个简单的网站应用程序，但我遇到了导航问题。

我在这个项目中使用 Visual Studio 2019。

我正在尝试从Views/Home/Index 导航到Views/Product/List，但一直无法导航（404 错误）。

这里是_Layout：

<nav class="navbar navbar-expand-md navbar-dark bg-primary">
        <a class="navbar-brand" href="/">SportsPro</a>
        <button class="navbar-toggler" type="button"
                data-toggle="collapse" data-target="#navbarSupportedContent"
                aria-controls="navbarSupportedContent" aria-expanded="false"
                aria-label="Toggle navigation">
            <span class="navbar-toggler-icon"></span>
        </button>
        <nav class="collapse navbar-collapse" id="navbarSupportedContent">
            <div class="navbar-nav mr-auto">
                <a class="nav-item nav-link active" asp-controller="Home" asp-action="Index">Home</a>
                <a class="nav-item nav-link active" asp-controller="Product" asp-action="List">Products</a>
                <a class="nav-item nav-link active" asp-controller="Technician" asp-action="List">Technicians</a>
                <a class="nav-item nav-link active" asp-controller="Customer" asp-action="List">Customers</a>
                <a class="nav-item nav-link active" asp-controller="Incident" asp-action="List">Incidents</a>
                <a class="nav-item nav-link active" asp-controller="Registration" asp-action="GetCustomer">Registrations</a>
            </div>
            <div class="navbar-nav navbar-right">
                <a class="nav-item nav-link active" asp-controller="Home" asp-action="About">About</a>
            </div>
        </nav>
    </nav>

查看Views/Product/List：

@model Product
@{
    ViewData["Title"] = "Products";
}
<h1>Product Manager</h1>
<form>...

HomeController:

using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Logging;
using SportsPro.Models;
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Threading.Tasks;

namespace SportsPro.Controllers
{
    public class HomeController : Controller
    {
        private SportsProContext context { get; set; }

        public HomeController(SportsProContext ctx)
        {
            context = ctx;
        }

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

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

        public IActionResult Privacy()
        {
            return View();
        }
       ....
    }
}

ProductController:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;
using SportsPro.Models;

namespace SportsPro.Controllers
{
    public class ProductController : Controller
    {
        private SportsProContext context { get; set; }

        public ProductController(SportsProContext ctx)
        {
            context = ctx;
        }

        [HttpGet]
        public IActionResult Add()
        {
            ViewBag.Action = "Add";
            ViewBag.ProductCode = context.Products.OrderBy(p => p.Name).ToList();
            return View("Edit", new Product());
        }

        [HttpGet]
        public IActionResult Edit(int id)
        {
            ViewBag.Action = "Edit";
            ViewBag.ProductCode = context.Products.OrderBy(p => p.Name).ToList();
            var product = context.Products.Find(id);
            return View(product);
        }

        [HttpPost]
        public IActionResult Edit(Product product)
        {
            if (ModelState.IsValid)
            {
                if (product.ProductID == 0)
                    context.Products.Add(product);
                else
                    context.Products.Update(product);

                context.SaveChanges();
                return RedirectToAction("List", "Product");
            }
            else
            {
                ViewBag.Action = (product.ProductID == 0) ? "Add" : "Edit";
                ViewBag.ProductCode = context.Products.OrderBy(p => p.Name).ToList();
                return View(product);
            }
        }

        [HttpGet]
        public IActionResult Delete(int id)
        {
            var product = context.Products.Find(id);
            return View(product);
        }

        [HttpPost]
        public IActionResult Delete(Product product)
        {
            context.Products.Remove(product);
            context.SaveChanges();
            return RedirectToAction("List", "Product");
        }
    }
}

还有其他代码示例可以帮助解决我的问题吗？我觉得我的问题在于我的ProductController。

Answer 1

据我了解，您想点击菜单栏上的产品按钮，然后转到您列出产品的页面。

<a class="nav-item nav-link active" asp-controller="Product" asp-action="List">Products</a>

上述代码的含义如下：转到您的产品控制器和该控制器的列出动作。

要做到这一点，您首先必须在产品控制器中创建一个名为 List() 的函数。到目前为止，您的 Product 控制器中似乎没有一个名为 List() 的函数。

public async Task<IActionResult> List()
{
     var products = await context.Products.ToListAsync();
     return View(products);
}

创建 List 函数后，您应该将模型从控制器返回到您的 Views/Product/List.cshtml

然后您可以在视图中使用该模型，如下所示：

@model IEnumerable<Product>

<div>
    @foreach(var product in Model){
        <a>@product.Name</a>
    }
<div>