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提供一个完整的 ASP.NET MVC 实现增删改查（CRUD）操作的示例。该示例使用 SQL Server 数据库，以一个简单的 Product 实体为例。

步骤 1：创建 ASP.NET MVC 项目

首先，在 Visual Studio 中创建一个新的 ASP.NET MVC 项目。

步骤 2：定义数据模型

在 Models 文件夹下创建 Product.cs 文件：

csharp

using System.ComponentModel.DataAnnotations;namespace YourNamespace.Models
{public class Product{public int Id { get; set; }[Required]public string Name { get; set; }[Required]public decimal Price { get; set; }}
}

步骤 3：创建数据库上下文

在 Models 文件夹下创建 ProductContext.cs 文件：

csharp

using Microsoft.EntityFrameworkCore;namespace YourNamespace.Models
{public class ProductContext : DbContext{public ProductContext(DbContextOptions<ProductContext> options) : base(options){}public DbSet<Product> Products { get; set; }}
}

步骤 4：配置数据库连接

在 appsettings.json 文件中添加数据库连接字符串：

json

{"ConnectionStrings": {"DefaultConnection": "Server=(localdb)\\mssqllocaldb;Database=YourDatabaseName;Trusted_Connection=True;MultipleActiveResultSets=true"},"Logging": {"LogLevel": {"Default": "Information","Microsoft.AspNetCore": "Warning"}},"AllowedHosts": "*"
}

步骤 5：在 Startup.cs 中配置数据库上下文

csharp

using Microsoft.EntityFrameworkCore;
using YourNamespace.Models;public void ConfigureServices(IServiceCollection services)
{services.AddDbContext<ProductContext>(options =>options.UseSqlServer(Configuration.GetConnectionString("DefaultConnection")));services.AddControllersWithViews();
}

步骤 6：创建控制器

在 Controllers 文件夹下创建 ProductController.cs 文件：

csharp

using Microsoft.AspNetCore.Mvc;
using YourNamespace.Models;
using System.Linq;namespace YourNamespace.Controllers
{public class ProductController : Controller{private readonly ProductContext _context;public ProductController(ProductContext context){_context = context;}// 显示所有产品public IActionResult Index(){var products = _context.Products.ToList();return View(products);}// 创建产品视图public IActionResult Create(){return View();}// 处理创建产品的 POST 请求[HttpPost][ValidateAntiForgeryToken]public IActionResult Create(Product product){if (ModelState.IsValid){_context.Products.Add(product);_context.SaveChanges();return RedirectToAction(nameof(Index));}return View(product);}// 编辑产品视图public IActionResult Edit(int? id){if (id == null){return NotFound();}var product = _context.Products.Find(id);if (product == null){return NotFound();}return View(product);}// 处理编辑产品的 POST 请求[HttpPost][ValidateAntiForgeryToken]public IActionResult Edit(int id, Product product){if (id != product.Id){return NotFound();}if (ModelState.IsValid){try{_context.Update(product);_context.SaveChanges();}catch{if (!ProductExists(product.Id)){return NotFound();}else{throw;}}return RedirectToAction(nameof(Index));}return View(product);}// 删除产品确认视图public IActionResult Delete(int? id){if (id == null){return NotFound();}var product = _context.Products.Find(id);if (product == null){return NotFound();}return View(product);}// 处理删除产品的 POST 请求[HttpPost, ActionName("Delete")][ValidateAntiForgeryToken]public IActionResult DeleteConfirmed(int id){var product = _context.Products.Find(id);_context.Products.Remove(product);_context.SaveChanges();return RedirectToAction(nameof(Index));}private bool ProductExists(int id){return _context.Products.Any(e => e.Id == id);}}
}

步骤 7：创建视图

在 Views 文件夹下创建 Product 文件夹，并在其中创建以下视图文件：

Index.cshtml

html

@model IEnumerable<YourNamespace.Models.Product>@{ViewData["Title"] = "Product List";
}<h1>Product List</h1><p><a asp-action="Create">Create New</a>
</p>
<table class="table"><thead><tr><th>@Html.DisplayNameFor(model => model.Name)</th><th>@Html.DisplayNameFor(model => model.Price)</th><th></th></tr></thead><tbody>@foreach (var item in Model){<tr><td>@Html.DisplayFor(modelItem => item.Name)</td><td>@Html.DisplayFor(modelItem => item.Price)</td><td>@Html.ActionLink("Edit", "Edit", new { id = item.Id }) |@Html.ActionLink("Delete", "Delete", new { id = item.Id })</td></tr>}</tbody>
</table>

Create.cshtml

html

@model YourNamespace.Models.Product@{ViewData["Title"] = "Create Product";
}<h1>Create Product</h1><form asp-action="Create"><div asp-validation-summary="ModelOnly" class="text-danger"></div><div class="form-group"><label asp-for="Name">Name</label><input asp-for="Name" class="form-control" /><span asp-validation-for="Name" class="text-danger"></span></div><div class="form-group"><label asp-for="Price">Price</label><input asp-for="Price" class="form-control" /><span asp-validation-for="Price" class="text-danger"></span></div><button type="submit" class="btn btn-primary">Create</button>
</form><div><a asp-action="Index">Back to List</a>
</div>

Edit.cshtml

html

@model YourNamespace.Models.Product@{ViewData["Title"] = "Edit Product";
}<h1>Edit Product</h1><form asp-action="Edit"><input type="hidden" asp-for="Id" /><div asp-validation-summary="ModelOnly" class="text-danger"></div><div class="form-group"><label asp-for="Name">Name</label><input asp-for="Name" class="form-control" /><span asp-validation-for="Name" class="text-danger"></span></div><div class="form-group"><label asp-for="Price">Price</label><input asp-for="Price" class="form-control" /><span asp-validation-for="Price" class="text-danger"></span></div><button type="submit" class="btn btn-primary">Save</button>
</form><div><a asp-action="Index">Back to List</a>
</div>

Delete.cshtml

html

@model YourNamespace.Models.Product@{ViewData["Title"] = "Delete Product";
}<h1>Delete Product</h1><h3>Are you sure you want to delete this?</h3>
<div><h4>Product</h4><hr /><dl class="row"><dt class="col-sm-2">@Html.DisplayNameFor(model => model.Name)</dt><dd class="col-sm-10">@Html.DisplayFor(model => model.Name)</dd><dt class="col-sm-2">@Html.DisplayNameFor(model => model.Price)</dt><dd class="col-sm-10">@Html.DisplayFor(model => model.Price)</dd></dl><form asp-action="DeleteConfirmed"><input type="hidden" asp-for="Id" /><button type="submit" class="btn btn-danger">Delete</button> |<a asp-action="Index">Back to List</a></form>
</div>

步骤 8：运行项目

运行项目，访问 Product 控制器的 Index 动作，你将看到产品列表页面，并可以进行增删改查操作。