经过一段时间的准备，新的一期【ASP.NET Core MVC开发实战之商城系统】已经开始，在之前的文章中，讲解了商城系统的整体功能设计，页面布局设计，环境搭建，系统配置，及首页【商品类型，banner条，友情链接，降价促销，新品爆款】，商品列表页面，商品详情等功能的开发，今天继续讲解购物车功能开发，仅供学习分享使用，如有不足之处，还请指正。

购物车功能说明

在首页或者商品列表页面，如果用户对商品感兴趣，可以点击快捷方式，将商品加入购物车；或者在商品详情页面，选择对应的商品参数后，将商品加入购物车。商品加入购物车的渠道是有多种，而用户也可以对已经加入购物车的商品进行购买，或者删除购物车。每一个用户都有各自的购物车，相互之间独立，所以购物车功能需要用户先进行登录，才能查看。

购物车功能设计

根据购物车功能说明，购物车主要显示已添加的商品列表，并可以删除，或者选择商品进行购买，设计页面如下所示：

购物车功能开发

购物车主要展示用户选择的商品信息。

1. 数据表创建

购物车表EB_Cart主要用于存储商品信息，用户信息，数量，及个人喜好等内容，如下所示：

购物车表创建语句如下所示：

CREATE TABLE [dbo].[EB_Cart]([Id] [bigint] IDENTITY(1,1) NOT NULL,[ProductId] [bigint] NULL,[CustomerId] [bigint] NULL,[Quantity] [int] NULL,[Remark] [varchar](200) NULL,[CreateTime] [datetime] NULL,[CreateUser] [varchar](50) NULL,[LastEditTime] [datetime] NULL,[LastEditUser] [varchar](50) NULL
) ON [PRIMARY]

2. 购物车实体创建

购物车实体和数据表结构保持一致，方便进行映射。如下所示：

using SqlSugar;namespace EasyBuyShop.Models
{/// <summary>/// 购物车/// </summary>[SugarTable("EB_Cart")]public class Cart:EntityModel{public long ProductId { get; set; }public long CustomerId { get; set; }/// <summary>/// 数量/// </summary>public int Quantity { get; set; }public string Remark { get; set; }}
}

3. 数据处理层DAL

购物车列表，主要包括添加购物车，删除，查询等功能，DAL层代码如下所示：

using EasyBuyShop.Models;
using EasyBuyShop.Utils;namespace EasyBuyShop.DAL
{public class CartDal:BaseDal{/// <summary>/// 获取购物车列表/// </summary>/// <param name="userId"></param>/// <returns></returns>public List<Cart> GetCartListByUserId(long userId){try{using (var db = this.GetDb(BaseDal.ConnStr)){return db.Queryable<Cart>().Where(r => r.CustomerId == userId).ToList();}}catch (Exception ex){LogHelper.Fatal(ex.Message);return new List<Cart>();}}public int DeleteById(long id){try{using (var db = this.GetDb(BaseDal.ConnStr)){int cnt = db.Deleteable<Cart>(r => r.Id == id).ExecuteCommand();return cnt;}}catch (Exception ex){LogHelper.Fatal(ex.Message);return -1;}}public Cart GetCart(long id){try{using (var db = this.GetDb(BaseDal.ConnStr)){return db.Queryable<Cart>().First(r => r.Id == id);}}catch (Exception ex){LogHelper.Fatal(ex.Message);return null;}}}
}

4. 控制器获取

控制器方法主要包括添加购物车【1.首页或商品列表快捷添加购物车 2.商品详情页面添加购物车】，查询购物车，删除购物车，代码如下所示：

using EasyBuyShop.DAL;
using EasyBuyShop.Models;
using Microsoft.AspNetCore.Mvc;namespace EasyBuyShop.Controllers
{/// <summary>/// 购物车控制器/// </summary>public class CartController : Controller{/// <summary>/// 购物车列表页面/// </summary>/// <returns></returns>public IActionResult Index(){var userId = HttpContext.Session.GetInt32("userid");if (userId == null){return Redirect("/Auth/login");}var cartDal = new CartDal();var productDal = new ProductDal();var cartList = cartDal.GetCartListByUserId((long)userId);var products = productDal.GetProductListByIds(cartList.Select(r => r.ProductId).ToList());ViewData["CartList"] = cartList;ViewData["ProductList"]= products;var username = HttpContext.Session.GetString("username");var realName = HttpContext.Session.GetString("realname");ViewData["Username"] = username;ViewData["RealName"] = realName;return View();}/// <summary>/// 首页或商品列表，快捷加入购物车/// </summary>/// <param name="productId"></param>/// <returns></returns>[HttpPost]public IActionResult Add(int productId){Msg msg = new Msg();var userId = HttpContext.Session.GetInt32("userid");var userName= HttpContext.Session.GetString("username");if (userId == null){msg.code = -1;msg.message = "尚未登录";return Json(msg);}var productDal = new ProductDal();var product = productDal.GetProduct(productId);if (product != null){var cartDal = new CartDal();var cart=new Cart();cart.ProductId = productId;cart.CustomerId = userId.Value;cart.Quantity = 1;cart.Remark= string.Empty;cart.CreateUser = userName;cart.CreateTime=DateTime.Now;cart.LastEditUser = userName;cart.LastEditTime = DateTime.Now;int id = cartDal.InsertT<Cart>(cart);if(id > 0){msg.code = 0;msg.message = "成功";return Json(msg);}else{msg.code = -1;msg.message = "加入购物车失败";return Json(msg);}}else{msg.code = -1;msg.message = "商品不存在";return Json(msg);}}/// <summary>/// 商品详情页面加入购物车/// </summary>/// <returns></returns>[HttpPost]public IActionResult AddWithForm(){Msg msg = new Msg();var userId = HttpContext.Session.GetInt32("userid");var userName = HttpContext.Session.GetString("username");if (userId == null){msg.code = -1;msg.message = "尚未登录";return Json(msg);}var productId =long.Parse( Request.Form["productId"]);var quantity = int.Parse(Request.Form["quantity"]);var color = Request.Form["color"];var size = Request.Form["size"];var remark = $"颜色：{color},大小：{size}";var productDal = new ProductDal();var product = productDal.GetProduct(productId);if (product != null){var cartDal = new CartDal();var cart = new Cart();cart.ProductId = productId;cart.CustomerId = userId.Value;cart.Quantity = quantity;cart.Remark = remark;cart.CreateUser = userName;cart.CreateTime = DateTime.Now;cart.LastEditUser = userName;cart.LastEditTime = DateTime.Now;int id = cartDal.InsertT<Cart>(cart);if (id > 0){msg.code = 0;msg.message = "成功";}else{msg.code = -1;msg.message = "加入购物车失败";}}else{msg.code = -1;msg.message = "商品不存在";}return Redirect("/Cart/Index");}/// <summary>/// 移除购物车/// </summary>/// <param name="Id"></param>/// <returns></returns>public ActionResult Delete(int Id){var cartDal =new CartDal();if(cartDal.DeleteById(Id) > 0){//成功}else{//删除失败}return View();}}
}

5. 视图层展示

在Views/Cart/Index.cshtml购物车视图中，接收控制器传递的参数。如下所示：

@{var totalPrice = 0.0M;
}
<div class="content-wrap"><div class="content"><!-- shopping-cart-area start --><div class="cart-area ptb-100"><form action="/Purchase/BuyWithCart" method="post"><div class="container"><div class="row"><div class="col-lg-12 col-md-12 col-sm-12 col-xs-12"><div class="table-content table-responsive"><table><thead><tr><th class="product-check">选择</th><th class="product-price">图片</th><th class="product-name">产品名称</th><th class="product-price">价格</th><th class="product-price">优惠价格</th><th class="product-quantity">数量</th><th class="product-subtotal">总计</th><th class="product-name">删除</th></tr></thead><tbody>@{var cartList = ViewData["CartList"] as List<Cart>;var productList = ViewData["ProductList"] as List<Product>;if (cartList.Count > 0){foreach (var cart in cartList){var product = productList.FirstOrDefault(r => r.Id == cart.ProductId);totalPrice = totalPrice + (product.PreferentialPrice * cart.Quantity);<tr><td class="product-check"><input type="checkbox" value="@(cart.Id)" name="chkCart" style="width:25px;height:25px;" checked="checked" onchange="javascript:checkCartProduct(this);" /></td><td class="product-thumbnail"><a href="/Product/Detail/@(product.Id)"><img src="@(product.ImageUrl)" alt="" width="100" height="100"></a></td><td class="product-name"><a href="/Product/Detail/@(product.Id)">@product.Name</a><br /><span style="font-size:12px; color:lightgray">备注：@(string.IsNullOrEmpty(cart.Remark) ? "无" : cart.Remark)</span></td><td class="product-price"><span class="amount">@(Math.Round(product.Price, 2))</span></td><td class="product-price"><span class="amount">@(Math.Round(product.PreferentialPrice, 2))</span></td><td class="product-quantity"><input value="@(cart.Quantity)" type="number"></td><td class="product-subtotal">@(Math.Round(product.PreferentialPrice * cart.Quantity, 2))</td><td class="product-remove"><a href="/Cart/Delete/@(cart.Id)"><i class="fa fa-times"><font style="font-size:14px;">删除</font></i></a></td></tr>}}else{<tr><td colspan="7">购物车暂无商品</td></tr>}}</tbody></table></div></div></div><div class="row tax-coupon-div"><div class="col-md-7 col-sm-12 col-xs-12"></div><div class="col-md-5 col-sm-12 col-xs-12"><div class="cart-total"><ul><li class="cart-black">总计<span>@totalPrice</span></li></ul><div class="cart-total-btn"><div class="cart-total-btn1 f-left"></div><div class="cart-total-btn2 f-right"><input type="submit" value="购买" class="go-btn" onclick="javascript:return checkSubmit();" style="background-color: rgb(255, 80, 0);border-width:0px;margin-top:5px;" /></div></div></div></div></div></div></form></div><!-- shopping-cart-area end --></div><!-- content end -->
</div>
<!-- content-wrap end -->
<script src="~/js/shop.js"></script>