C# - 基于.NetCore开发的“寸金游”（后端开发）

一、前情提要

模块 or 架构

RESTful成熟度模型

二、【项目启动】ASP.Net Core API 上手指南

.Net Core的前世今生

Asp.Net Core MVC

MVC架构设计模式。
基于.Net的应用框架。

创建实战项目

下载.Net6

https://dotnet.microsoft.com/zh-cn/download

CMD中输入`dotnet --version`测试.Net是否安装成功

配置VS工作负荷ASP.NET

创建Hello World项目

namespace _00NET___HelloWorld
{
    internal class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Hello, World!");
        }
    }
}

新建项目ASP.NET Core Web应用

运行测试

选择IIS服务器或者本地服务器

.NET Core的中间件、请求通道、以及环境设置

请求通道Request Pipeline

中间件Middelware

添加第一个API

注册MVC的框架依赖（Startup.cs）

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;

namespace _01NET___CJ_ASP_Travel
{
    public class Startup
    {
        // This method gets called by the runtime. Use this method to add services to the container.
        // For more information on how to configure your application, visit https://go.microsoft.com/fwlink/?LinkID=398940
        public void ConfigureServices(IServiceCollection services)
        {
            services.AddControllers();
        }

        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
        {
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }

            app.UseRouting();

            app.UseEndpoints(endpoints =>
            {
                endpoints.MapControllers();
            });
        }
    }
}

新建Controllers文件夹

建立API控制器类TestApiController.cs

using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;

namespace _01NET___CJ_ASP_Travel.Controllers
{
    [Route("api/[controller]")]
    [ApiController]
    public class TestApiController : ControllerBase
    {
        // GET: api/<controller>
        [HttpGet]
        public IEnumerable<string> Get()
        {
            return new string[] { "value1", "value2" };
        }

        // GET api/<controller>/5
        [HttpGet("{id}")]
        public string Get(int id)
        {
            return "value";
        }

        // POST api/<controller>
        [HttpPost]
        public void Post([FromBody] string value)
        {
        }

        // PUT api/<controller>/5
        [HttpPut("{id}")]
        public void Put(int id, [FromBody] string value)
        {
        }

        // DELETE api/<controller>/5
        [HttpDelete("{id}")]
        public void Delete(int id)
        {
        }
    }
}

访问https://localhost:7249/api/testapi

请求成功

新建ShoudongAPI.cs

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

namespace _01NET___CJ_ASP_Travel.Controllers
{
    [Route("api/shoudongapi")]
    //[Controller]
    //public class ShoudongAPIController
    public class ShoudongAPI : Controller
    {
        [HttpGet]
        public  IEnumerable<string> Get()
        {
            return new string[] { "value1", "value2" };
        }
    }
}

访问https://localhost:7249/api/shoudongapi

普通的类文件如何识别为控制器类

[Controller]
xxController
xx : Controller

[Route("api/shoudongapi")]
[Controller]
public class ShoudongAPIController
    
public class

任选一种方式即可。

MVC架构

ASP.NET Core MVC框架

什么是MVC

视图View

模型Model

控制器Controller

MVC架构的数据是如何流动？

MVC的优点

耦合性低
可复用性高
可维护性高

三、【数据构建】数据模型与数据库设计

模型优先设计数据库结构、搭建数据仓库接口。
学习Entity Framework。
使用docker启动课程的数据库
使用dotnet CLI命令行来创建、初始化、更新数据库。

商城数据模型设计

数据模型设计指南

正确的项目启动思路

业务线（DDD）

根据业务模块建立数据模型

ER关系

逻辑 or 物理概念

数据模型与仓库模式

数据模型的作用

映射数据库，对象化数据。
获取数据、更新数据、传递数据、保存数据等。
处理业务逻辑，视为Business Layer业务层。
View Model与视图数据绑定。

代码示例

如何从数据库中获取数据呢？

repository仓库模式

Model的文件结构

使用模型和数据仓库的好处

业务逻辑与数据模型紧密耦合，减少分层、降低代码数量。
完全剥离数据库业务，程序猿可以更专注于实现业务逻辑。
面向对象编程，数据转化为对象。

面向对象编程

创建数据模型和数据仓库

新建Models文件夹

创建数据模型

新增TouristRoute.cs类

namespace _01NET___CJ_ASP_Travel.Models
{
    public class TouristRoute
    {
        public Guid Id { get; set; }
        public string Title { get; set; }

        //路线简介
        public string Description { get; set; }

        //原价
        public decimal OriginalPrice { get; set; }

/*        ？可控类型*//*折扣*/
        public double? DiscountPresent { get; set; }

        //线路发布时间
        public DateTime CreateTime { get; set; }

        //线路更新时间
        public DateTime UpdateTime { get; set; }

        //出发时间
        public DateTime? DepartureTime { get; set; }

        //说明
        public string Features { get; set; }

        //费用说明
        public string Fees { get; set; }
        public string Notes { get; set; }

        //建立相应的外键关系TouristRoutePicture.cs
        public ICollection<TouristRoutePicture> touristRoutePictures { get; set; }
    }
}

新增TouristRoutePicture.cs

namespace _01NET___CJ_ASP_Travel.Models
{
    public class TouristRoutePicture
    {
        public int Id { get; set; }

        //照片属性
        public string Url { get; set; }

        //与旅游路线相关的外键关系
        public Guid TouristRouteId { get; set; }

        //连接关系
        public TouristRoute TouristRoute { get; set; }
    }
}

建立数据仓库

新建Services文件夹

新建接口（interface）ITouristRouteRepository

using _01NET___CJ_ASP_Travel.Models;

namespace _01NET___CJ_ASP_Travel.Services
{
    public interface ITouristRouteRepository
    {
        //返回一组旅游路线
        IEnumerable<TouristRoute> GetTouristRoutes();

        //返回单独的旅游路线
        TouristRoute GetTouristRoute(Guid touristRouteId);
    }
}

新建类（Mock假数据）MockTouristRouteRepository

using _01NET___CJ_ASP_Travel.Models;

namespace _01NET___CJ_ASP_Travel.Services
{
    public class MockTouristRouteRepository : ITouristRouteRepository
    {
        private List<TouristRoute> _routes;

        public MockTouristRouteRepository()
        {
            if (_routes == null)
            {
                InitializeTouristRoutes();
            }
        }

        private void InitializeTouristRoutes()
        {
            _routes = new List<TouristRoute>
            {
                new TouristRoute {
                    Id = Guid.NewGuid(),
                    Title = "黄山",
                    Description="黄山真好玩",
                    OriginalPrice = 1299,
                    Features = "<p>吃住行游购娱</p>",
                    Fees = "<p>交通费用自理</p>",
                    Notes="<p>小心危险</p>"
                },
                new TouristRoute {
                    Id = Guid.NewGuid(),
                    Title = "华山",
                    Description="华山真好玩",
                    OriginalPrice = 1299,
                    Features = "<p>吃住行游购娱</p>",
                    Fees = "<p>交通费用自理</p>",
                    Notes="<p>小心危险</p>"
                }
            };
        }
        public TouristRoute GetTouristRoute(Guid touristRouteId)
        {
            //linq语法
            return _routes.FirstOrDefault(n => n.Id == touristRouteId);
        }

        public IEnumerable<TouristRoute> GetTouristRoutes()
        {
            return _routes;
        }
    }
}

Startup.cs

注册数据仓库的服务依赖

services.AddSingleton
services.AddScoped
services.AddTransient

        public void ConfigureServices(IServiceCollection services)
        {
            services.AddControllers();
            //注册数据仓库的服务依赖
            //以下三个Add都可以用于依赖注入
            //services.AddSingleton
            //services.AddScoped
            services.AddTransient<ITouristRouteRepository, MockTouristRouteRepository>();
        }

通过Api展示数据

Controllers - TouristRoutesController.cs

API控制器

using _01NET___CJ_ASP_Travel.Services;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;

namespace _01NET___CJ_ASP_Travel.Controllers
{
    [Route("api/[controller]")]
    [ApiController]
    public class TouristRoutesController : ControllerBase
    {
        private ITouristRouteRepository _touristRouteRepository;
        public TouristRoutesController(ITouristRouteRepository touristRouteRepository)
        {
            _touristRouteRepository = touristRouteRepository;
        }
        public IActionResult GetTouristRoutes()
        { 
            var route =_touristRouteRepository.GetTouristRoutes();
            return Ok(route); 
        }
    }
}

测试

输入https://localhost:7249/api/TouristRoutes

什么是Entity Framework

Entity Framework Core

EF的组件

添加Entity Framework Core

新建Database文件夹

数据库映射工具AppDbContext.cs

using _01NET___CJ_ASP_Travel.Models;
using Microsoft.EntityFrameworkCore;

namespace _01NET___CJ_ASP_Travel.Database
{
    public class AppDbContext:DbContext
    {
        public AppDbContext(DbContextOptions<AppDbContext> options) : base(options)
        {
        
        }

        public DbSet<TouristRoute> TouristRoutes { get; set; }
        public DbSet<TouristRoutePicture> TouristRoutePictures { get; set; }
    }
}

Startup.cs

    public class Startup
    {

        private IConfiguration Configuration { get; }

        public Startup(IConfiguration configuration)
        {
            Configuration = configuration;
        }
        // This method gets called by the runtime. Use this method to add services to the container.
        // For more information on how to configure your application, visit https://go.microsoft.com/fwlink/?LinkID=398940
        public void ConfigureServices(IServiceCollection services)
        {
            services.AddControllers();
            //注册数据仓库的服务依赖
            //以下三个Add都可以用于依赖注入
            //services.AddSingleton
            //services.AddScoped
            services.AddTransient<ITouristRouteRepository, TouristRouteRepository>();

            /*            数据库映射*/
            services.AddDbContext<AppDbContext>
                (options => {
                    options.UseSqlServer(Configuration["DbContext:ConnectionString"]);
                });
        }
        //--------------------------------------
        }

安装包Microsoft.EntityFrameworkCore.SqlServer

在appsettings.json中配置数据库连接字符串

ConnectionString

{
    "Logging": {
        "LogLevel": {
            "Default": "Information",
            "Microsoft.AspNetCore": "Warning"
        }
    },
    "AllowedHosts": "*",
    "DbContext": {
        "ConnectionString": "Data Source=DESKTOP-V6GQHHS\\SQLSERVER2012;Initial Catalog=master;Integrated Security=True"
    }
}

Services - TouristRouteRepository.cs

using _01NET___CJ_ASP_Travel.Database;
using _01NET___CJ_ASP_Travel.Models;

namespace _01NET___CJ_ASP_Travel.Services
{
    public class TouristRouteRepository : ITouristRouteRepository
    {
        private readonly AppDbContext _context;

        public TouristRouteRepository(AppDbContext appDbContext)
        {
            _context = appDbContext;
        }

        public TouristRoute GetTouristRoute(Guid touristRouteId)
        {
            return _context.TouristRoutes.FirstOrDefault(n => n.Id == touristRouteId);
        }

        public IEnumerable<TouristRoute> GetTouristRoutes()
        {
            return _context.TouristRoutes;
        }
    }
}

创建数据库

使用EntityFramework创建数据库

验证数据模型

添加数据库限制，主键信息，以及外键联系信息等等。

TouristRoute.cs

using System.ComponentModel.DataAnnotations;

using System.ComponentModel.DataAnnotations;
using Microsoft.EntityFrameworkCore.Metadata.Internal;
using System.ComponentModel.DataAnnotations.Schema;

namespace _01NET___CJ_ASP_Travel.Models
{
    public class TouristRoute
    {
        [Key]
        public Guid Id { get; set; }

        [Required]
        [MaxLength(100)]
        public string Title { get; set; }

        //路线简介
        [Required]
        [MaxLength(1500)]
        public string Description { get; set; }

        //原价
        [Column(TypeName = "decimal(18, 2)")]
        public decimal OriginalPrice { get; set; }

        /*        ？可控类型*//*折扣*/
        [Range(0.0, 1.0)]
        public double? DiscountPresent { get; set; }

        //线路发布时间
        public DateTime CreateTime { get; set; }

        //线路更新时间
        public DateTime UpdateTime { get; set; }

        //出发时间
        public DateTime? DepartureTime { get; set; }

        //说明
        [MaxLength]
        public string Features { get; set; }

        //费用说明
        [MaxLength]
        public string Fees { get; set; }

        [MaxLength]
        public string Notes { get; set; }

        //建立相应的外键关系TouristRoutePicture.cs
        public ICollection<TouristRoutePicture> TouristRoutePictures { get; set; }
            = new List<TouristRoutePicture>();
    }
}

TouristRoutePicture.cs

using System.ComponentModel.DataAnnotations.Schema;
using System.ComponentModel.DataAnnotations;

namespace _01NET___CJ_ASP_Travel.Models
{
    public class TouristRoutePicture
    {
        [Key]
        [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
        public int Id { get; set; }

        //照片属性
        [MaxLength(100)]
        public string Url { get; set; }

        //与旅游路线相关的外键关系
        [ForeignKey("TouristRouteId")]
        public Guid TouristRouteId { get; set; }

        //连接关系
        public TouristRoute TouristRoute { get; set; }
    }
}

数据库创建工具:Entity Framework Core Tools

Package Manage Console (PMC)

如果报错，请降低包版本。

add-migration initialMigration
    
update-database

数据库创建成功

添加初始化数据

AppDbContext.cs - 重写OnModelCreating()

using System.Reflection;
using _01NET___CJ_ASP_Travel.Models;
using Microsoft.EntityFrameworkCore;
using Newtonsoft.Json;

namespace _01NET___CJ_ASP_Travel.Database
{
    public class AppDbContext:DbContext
    {
        public AppDbContext(DbContextOptions<AppDbContext> options) : base(options)
        {
        
        }

        public DbSet<TouristRoute> TouristRoutes { get; set; }
        public DbSet<TouristRoutePicture> TouristRoutePictures { get; set; }

        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {

            var touristRouteJsonData = File.ReadAllText(Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location) + @"/Database/touristRoutesMockData.json");
            IList<TouristRoute> touristRoutes = JsonConvert.DeserializeObject<IList<TouristRoute>>(touristRouteJsonData);
            modelBuilder.Entity<TouristRoute>().HasData(touristRoutes);

            var touristRoutePictureJsonData = File.ReadAllText(Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location) + @"/Database/touristRoutePicturesMockData.json");
            IList<TouristRoutePicture> touristRoutePictures = JsonConvert.DeserializeObject<IList<TouristRoutePicture>>(touristRoutePictureJsonData);
            modelBuilder.Entity<TouristRoutePicture>().HasData(touristRoutePictures);

            base.OnModelCreating(modelBuilder);
        }
    }
}

更新数据请用Package Manage Console (PMC)

如果报错，请降低包版本。

add-migration initialMigration
    
update-database

数据导入成功。

测试

更新数据库

新增代码TouristRoute.cs

using System.ComponentModel.DataAnnotations;
using Microsoft.EntityFrameworkCore.Metadata.Internal;
using System.ComponentModel.DataAnnotations.Schema;

namespace _01NET___CJ_ASP_Travel.Models
{
    public class TouristRoute
    {
        //--------------------------省略

        //评分
        public double? Rating { get; set; }

        //旅行天数
        public TravelDays TravelDays { get; set; }

        //旅游类型
        public TripType? TripType { get; set; }

        //出发地
        public DepartureCity? DepartureCity { get; set; }
    }
}

Models - 新建TravelDays.cs

namespace _01NET___CJ_ASP_Travel.Models
{
    public enum TravelDays
    {
        One,
        Two,
        Three,
        Four,
        Five,
        Six,
        Seven,
        Eight,
        EightPlus
    }
}

新建TripType.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace _01NET___CJ_ASP_Travel.Models
{
    public enum TripType
    {
        HotelAndAttractions, //酒店+景点
        Group, //跟团游
        PrivateGroup, //私家团
        BackPackTour, //自由行
        SemiBackPackTour//半自助游
    }
}

新建DepartureCity.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace  _01NET___CJ_ASP_Travel.Models
{
    public enum DepartureCity
    {
        Beijing, //北京
        Shanghai, //上海
        Canton, //广州
        Shenzhen, //深圳
    }
}

更新数据库

四、【API成熟度】通往真正REST的之路

RESTful的基础知识

RESTful的基本特点

无状态
面向“资源”
使用HTTP的动词
HATOAS超媒体即应用状态引擎

RESTful的6个约束与最佳实践

6个约束限制

总结常用的HTTP请求方法

Richardson四个级别的成熟度模型与 HATOAS

Richardson四个级别的成熟度模型

LEVEL 0

LEVEL 1 - 资源

LEVEL 2 - HTTP动词

LEVEL 3 - 超媒体控制

RESTfulAPI范例

五、【获取产品】RESTful面向资源入门

目标

Http Get 获取资源

修改 TouristRoutesController - GetTouristRouteById

        // api/touristroutes/{touristRouteId}
        [HttpGet("{touristRouteId}")]
        public IActionResult GetTouristRouteById(Guid touristRouteId)
        {
            return Ok(_touristRouteRepository.GetTouristRoute(touristRouteId));
        }

使用postman测试api

https://localhost:7249/api/TouristRoutes/39996f34-013c-4fc6-b1b3-0c1036c47110

Status Code 的重要性

HTTP状态码

常见的HTTP状态码

返回正确的 Status Codes

修改 TouristRoutesController - GetTouristRouteById 和 GetTouristRoutes

        [HttpGet]
        public IActionResult GetTouristRoutes()
        { 
            var touristRoutesFromRepo = _touristRouteRepository.GetTouristRoutes();
            if (touristRoutesFromRepo == null || touristRoutesFromRepo.Count() <= 0)
            { 
                return NotFound("没有旅游路线");
            }
            return Ok(touristRoutesFromRepo); 
        }

        // api/touristroutes/{touristRouteId}
        [HttpGet("{touristRouteId}")]
        public IActionResult GetTouristRouteById(Guid touristRouteId)
        {
            var touristRouteFromRepo = _touristRouteRepository.GetTouristRoute(touristRouteId);
            if (touristRouteFromRepo == null)
            {
                return NotFound($"旅游路线{touristRouteId}找不到");
            }
            return Ok(touristRouteFromRepo);
        }

测试404

内容协商与数据格式

内容协商

允许客户端和服务器通过协商来决定相互之间的数据传输格式、语言等内容。

内容协商与数据格式

实现内容协商

Startup.cs - services.AddControllers

        public void ConfigureServices(IServiceCollection services)
        {
            services.AddControllers(setupAction =>
            {
                setupAction.ReturnHttpNotAcceptable = true;
            }).AddXmlDataContractSerializerFormatters();
            //注册数据仓库的服务依赖
            //-------------------------省略
            
        }

测试

header中xml的请求

显示xml结构数据

反之，显示json结构

数据模型(Model) vs. 数据传输对象(DTO)

使用数据模型带来了两个不稳定因素

直接向前端返回数据模型，会暴露系统的业务核心。
颗粒度太粗，也就是输出数据无法精细调整。

数据传输对象(DTO)

数据模型(Model) vs. 数据传输对象(DTO)

Model面向业务。
DTO则是面向界面、面向UI。
使用DTO的时候可以屏蔽我们不希望暴露的核心业务。
通过不同dto的组合，又可以调整输出数据的结果，从而解决颗粒度太粗的问题。

分离Model与DTO

新建Dtos文件夹 - TouristRouteDto.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace _01NET___CJ_ASP_Travel.Dtos
{
    public class TouristRouteDto
    {
        public Guid Id { get; set; }
        public string Title { get; set; }
        public string Description { get; set; }
        // 计算方式：原价 * 折扣
        public decimal Price { get; set; }
        //public decimal OriginalPrice { get; set; }
        //public double? DiscountPresent { get; set; }
        public DateTime CreateTime { get; set; }
        public DateTime? UpdateTime { get; set; }
        public DateTime? DepartureTime { get; set; }
        public string Features { get; set; }
        public string Fees { get; set; }
        public string Notes { get; set; }
        public double? Rating { get; set; }
        public string TravelDays { get; set; }
        public string TripType { get; set; }
        public string DepartureCity { get; set; }
    }
}

在TouristRoutesController.cs中修改GetTouristRouteById方法

// api/touristroutes/{touristRouteId}
        [HttpGet("{touristRouteId}")]
        public IActionResult GetTouristRouteById(Guid touristRouteId)
        {
            var touristRouteFromRepo = _touristRouteRepository.GetTouristRoute(touristRouteId);
            if (touristRouteFromRepo == null)
            {
                return NotFound($"旅游路线{touristRouteId}找不到");
            }

            var touristRouteDto = new TouristRouteDto()
            {
                Id = touristRouteFromRepo.Id,
                Title = touristRouteFromRepo.Title,
                Description = touristRouteFromRepo.Description,
              Price = touristRouteFromRepo.OriginalPrice * (decimal)(touristRouteFromRepo.DiscountPresent ?? 1),
                CreateTime = touristRouteFromRepo.CreateTime,
                UpdateTime = touristRouteFromRepo.UpdateTime,
               Features = touristRouteFromRepo.Features,
               Fees = touristRouteFromRepo.Fees,
                    Notes = touristRouteFromRepo.Notes,
                Rating = touristRouteFromRepo.Rating,
                TravelDays = touristRouteFromRepo.TravelDays.ToString(),
                    TripType = touristRouteFromRepo.TripType.ToString(),
                    DepartureCity = touristRouteFromRepo.DepartureCity.ToString()
              };

            return Ok(touristRouteFromRepo);
        }

使用 AutoMapper 自动映射数据

注册到IOC容器中 - Startup.cs - ConfigureServices

        public void ConfigureServices(IServiceCollection services)
        {
            //------------------------省略

            // 扫描profile文件
            services.AddAutoMapper(AppDomain.CurrentDomain.GetAssemblies());
        }

新建Profiles文件夹 - TouristRouteProfile.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using AutoMapper;


namespace _01NET___CJ_ASP_Travel.Profiles
{
    public class TouristRouteProfile : Profile
    {
        public TouristRouteProfile()
        {
            CreateMap<TouristRoute, TouristRouteDto>()
                .ForMember(
                    dest => dest.Price,
                    opt => opt.MapFrom(src => src.OriginalPrice * (decimal)(src.DiscountPresent ?? 1))
                )
                .ForMember(
                    dest => dest.TravelDays,
                    opt => opt.MapFrom(src => src.TravelDays.ToString())
                )
                .ForMember(
                    dest => dest.TripType,
                    opt => opt.MapFrom(src => src.TripType.ToString())
                )
                .ForMember(
                    dest => dest.DepartureCity,
                    opt => opt.MapFrom(src => src.DepartureCity.ToString())
                );
        }
    }
}

修改GetTouristRouteById方法和 GetTouristRoutes方法（TouristRoutesController.cs）

var touristRoutesDto

            private readonly IMapper _mapper;

        [HttpGet]
        public IActionResult GetTouristRoutes()
        { 
            var touristRoutesFromRepo = _touristRouteRepository.GetTouristRoutes();
            if (touristRoutesFromRepo == null || touristRoutesFromRepo.Count() <= 0)
            { 
                return NotFound("没有旅游路线");
            }
            var touristRoutesDto = _mapper.Map<IEnumerable<TouristRouteDto>>(touristRoutesFromRepo);
            return Ok(touristRoutesFromRepo); 
        }

// api/touristroutes/{touristRouteId}
        [HttpGet("{touristRouteId}")]
        public IActionResult GetTouristRouteById(Guid touristRouteId)
        {
            var touristRouteFromRepo = _touristRouteRepository.GetTouristRoute(touristRouteId);
            if (touristRouteFromRepo == null)
            {
                return NotFound($"旅游路线{touristRouteId}找不到");
            }
            var touristRouteDto = _mapper.Map<TouristRouteDto>(touristRouteFromRepo);
            return Ok(touristRouteFromRepo);
        }

获取嵌套对象关系型数据

Controllers文件夹 - TouristRoutePicturesController.cs

using _01NET___CJ_ASP_Travel.Dtos;
using _01NET___CJ_ASP_Travel.Services;
using AutoMapper;
using Microsoft.AspNetCore.Mvc;

namespace _01NET___CJ_ASP_Travel.Controllers
{
    [Route("api/touristRoutes/{touristRouteId}/pictures")]
    [ApiController]
    public class TouristRoutePicturesController : ControllerBase
    {
        private ITouristRouteRepository _touristRouteRepository;
        private IMapper _mapper;

        public TouristRoutePicturesController(
            ITouristRouteRepository touristRouteRepository,
            IMapper mapper
        )
        {
            _touristRouteRepository = touristRouteRepository ??
                throw new ArgumentNullException(nameof(touristRouteRepository));
            _mapper = mapper ??
                throw new ArgumentNullException(nameof(mapper));
        }

        [HttpGet]
        public IActionResult GetPictureListForTouristRoute(Guid touristRouteId)
        {
            if (!_touristRouteRepository.TouristRouteExists(touristRouteId))
            {
                return NotFound("旅游线路不存在");
            }

            var picturesFromRepo = _touristRouteRepository.GetPicturesByTouristRouteId(touristRouteId);
            if (picturesFromRepo == null || picturesFromRepo.Count() <= 0)
            {
                return NotFound("照片不存在");
            }

            return Ok(_mapper.Map<IEnumerable<TouristRoutePictureDto>>(picturesFromRepo));

        }

    }
}

Dtos文件夹 - TouristRoutePictureDto.cs

namespace _01NET___CJ_ASP_Travel.Dtos
{
    public class TouristRoutePictureDto
    {
        public int Id { get; set; }
        public string Url { get; set; }
        public Guid TouristRouteId { get; set; }
    }
}

Profiles文件夹 - TouristRoutePictureProfile.cs

using _01NET___CJ_ASP_Travel.Dtos;
using _01NET___CJ_ASP_Travel.Models;
using AutoMapper;

namespace _01NET___CJ_ASP_Travel.Profiles
{
    public class TouristRoutePictureProfile : Profile
    {
        public TouristRoutePictureProfile()
        {
            CreateMap<TouristRoutePicture, TouristRoutePictureDto>();
        }
    }
}

Services - ITouristRouteRepository.cs - 添加新的接口函数

bool TouristRouteExists(Guid touristRouteId);
        IEnumerable<TouristRoutePicture> GetPicturesByTouristRouteId(Guid touristRouteId);

实现接口函数 - TouristRouteRepository.cs

        public bool TouristRouteExists(Guid touristRouteId)
        {
            return _context.TouristRoutes.Any(t => t.Id == touristRouteId);
        }

        public IEnumerable<TouristRoutePicture> GetPicturesByTouristRouteId(Guid touristRouteId)
        {
            return _context.TouristRoutePictures
                .Where(p => p.TouristRouteId == touristRouteId).ToList();
        }

注释假数据代码文件（Mock）

测试

https://localhost:7249/api/TouristRoutes/39996f34-013c-4fc6-b1b3-0c1036c47110/pictures

单独获取子资源

TouristRoutePicturesController.cs

        [HttpGet("{pictureId}")]
        public IActionResult GetPicture(Guid touristRouteId, int pictureId) 
        {
            if (!_touristRouteRepository.TouristRouteExists(touristRouteId))
            {
                return NotFound("旅游线路不存在");
            }

            var pictureFromRepo = _touristRouteRepository.GetPicture(pictureId);
            if(pictureFromRepo == null)
            {
                return NotFound("相片不存在");
            }
            return Ok(_mapper.Map<TouristRoutePictureDto>(pictureFromRepo));
        }

TouristRouteRepository.cs

        public TouristRoutePicture GetPicture(int pictureId)
        {
            return _context.TouristRoutePictures.Where(p => p.Id == pictureId).FirstOrDefault();
        }

ITouristRouteRepository.cs

        TouristRoutePicture GetPicture(int pictureId);

测试

完善automapper的嵌套映射

（TouristRouteRepository.cs）修改`GetTouristRoute`

        public TouristRoute GetTouristRoute(Guid touristRouteId)
        {
            return _context.TouristRoutes.Include(t => t.TouristRoutePictures).FirstOrDefault(n => n.Id == touristRouteId);
        }

        public IEnumerable<TouristRoute> GetTouristRoutes()
        {
            // include vs join
            return _context.TouristRoutes.Include(t => t.TouristRoutePictures);
        }

TouristRouteDto.cs

public ICollection<TouristRoutePictureDto> TouristRoutePictures { get; set; }

使用http的HEAD请求

HTTP HEAD

HEAD与GET类似，但没有响应主体。
检测缓存。
探测资源是否存在。

TouristRoutesController.cs

直接加上[HttpHead]

using _01NET___CJ_ASP_Travel.Dtos;
using _01NET___CJ_ASP_Travel.Services;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using AutoMapper;

namespace _01NET___CJ_ASP_Travel.Controllers
{
    [Route("api/[controller]")] // api/touristroute
    [ApiController]
    public class TouristRoutesController : ControllerBase
    {
        private ITouristRouteRepository _touristRouteRepository;
        private readonly IMapper _mapper;
        /*        public TouristRoutesController(ITouristRouteRepository touristRouteRepository)
                {
                    _touristRouteRepository = touristRouteRepository;
                }*/
        public TouristRoutesController(
            ITouristRouteRepository touristRouteRepository,
            IMapper mapper
        )
        {
            _touristRouteRepository = touristRouteRepository;
            _mapper = mapper;
        }

        [HttpGet]
        [HttpHead]
        public IActionResult GerTouristRoutes()
        {
            var touristRoutesFromRepo = _touristRouteRepository.GetTouristRoutes();
            if (touristRoutesFromRepo == null || touristRoutesFromRepo.Count() <= 0)
            {
                return NotFound("没有旅游路线");
            }
            var touristRoutesDto = _mapper.Map<IEnumerable<TouristRouteDto>>(touristRoutesFromRepo);
            return Ok(touristRoutesDto);
        }


        // api/touristroutes/{touristRouteId}
        [HttpGet("{touristRouteId}")]
        [HttpHead]
        public IActionResult GetTouristRouteById(Guid touristRouteId)
        {
            var touristRouteFromRepo = _touristRouteRepository.GetTouristRoute(touristRouteId);
            if (touristRouteFromRepo == null)
            {
                return NotFound($"旅游路线{touristRouteId}找不到");
            }
            var touristRouteDto = _mapper.Map<TouristRouteDto>(touristRouteFromRepo);
            return Ok(touristRouteFromRepo);
        }
    }
}

六、【复合搜索】深入理解GET请求

向 API 传入参数

使用Attribute:[FromXXX]

[FromQuery] vs [Frompath]

关键词搜索

TouristRoutesController.cs - GerTouristRoutes方法添加参数

[FromQuery] string keyword

        // api/touristRoutes?keyword=传入的参数
        [HttpGet]
        [HttpHead]
        public IActionResult GerTouristRoutes([FromQuery] string keyword) // FromQuery vs FromBody
        {
            var touristRoutesFromRepo = _touristRouteRepository.GetTouristRoutes(keyword);
            if (touristRoutesFromRepo == null || touristRoutesFromRepo.Count() <= 0)
            {
                return NotFound("没有旅游路线");
            }
            var touristRoutesDto = _mapper.Map<IEnumerable<TouristRouteDto>>(touristRoutesFromRepo);
            return Ok(touristRoutesDto);
        }

更新数据仓库ITouristRouteRepository.cs

GetTouristRoutes接口加上参数

        //返回一组旅游路线
        IEnumerable<TouristRoute> GetTouristRoutes(string keyword);

更新这个接口实现TouristRouteRepository.cs

GetTouristRoutes

使用IQueryable

        public IEnumerable<TouristRoute> GetTouristRoutes(string keyword)
        {
            IQueryable<TouristRoute> result = _context.TouristRoutes
                .Include(t => t.TouristRoutePictures);
            if (!string.IsNullOrWhiteSpace(keyword))
            {
                keyword= keyword.Trim();
                result = result.Where(t => t.Title.Contains(keyword));
            }
            // include vs join
            return result.ToList();
        }

测试

https://localhost:7249/api/TouristRoutes?keyword=埃及

延迟执行 IQueryable

IQueryable的执行逻辑

延迟执行的目的

为后续动态表达提供可能
减少数据库的执行次数

Entity Framework的最佳工具: linq

Linq to sql
Linq to object
Linq to entity

数据过滤

TouristRoutesController.cs - GerTouristRoutes

string rating

        // api/touristRoutes?keyword=传入的参数
        [HttpGet]
        [HttpHead]
        public IActionResult GerTouristRoutes(
            [FromQuery] string keyword,
            string rating // 小于lessThan, 大于largerThan, 等于equalTo lessThan3, largerThan2, equalTo5 
            ) // FromQuery vs FromBody
        {

            Regex regex = new Regex(@"([A-Za-z0-9\-]+)(\d+)");
            string operatorType = "";
            int raringVlaue = -1;
            Match match = regex.Match(rating);
            if (match.Success)
            {
                operatorType = match.Groups[1].Value;
                raringVlaue = Int32.Parse(match.Groups[2].Value);
            }

            var touristRoutesFromRepo = _touristRouteRepository.GetTouristRoutes(keyword, operatorType, raringVlaue);
            if (touristRoutesFromRepo == null || touristRoutesFromRepo.Count() <= 0)
            {
                return NotFound("没有旅游路线");
            }
            var touristRoutesDto = _mapper.Map<IEnumerable<TouristRouteDto>>(touristRoutesFromRepo);
            return Ok(touristRoutesDto);
        }

数据仓库 - 接口文件ITouristRouteRepository.cs - 添加两个参数

string ratingOperator, int ratingValue

//返回一组旅游路线
        IEnumerable<TouristRoute> GetTouristRoutes(string keyword, string ratingOperator, int ratingValue);

更新代码实现 - TouristRouteRepository.cs - GetTouristRoutes

string ratingOperator, int ratingValue

if (ratingValue >= 0)

public IEnumerable<TouristRoute> GetTouristRoutes(string keyword, string ratingOperator, int ratingValue)
        {
                        IQueryable<TouristRoute> result = _context.TouristRoutes
                .Include(t => t.TouristRoutePictures);
            if (!string.IsNullOrWhiteSpace(keyword))
            {
                keyword= keyword.Trim();
                result = result.Where(t => t.Title.Contains(keyword));
            }

            if (ratingValue >= 0)
            {
                result = ratingOperator switch
                {
                    "largerThan" => result.Where(t => t.Rating >= ratingValue),
                    "lessThan" => result.Where(t => t.Rating <= ratingValue),
                    _ => result.Where(t => t.Rating == ratingValue),
                };
            }
            // include vs join
            return result.ToList();
        }

测试

https://localhost:7249/api/TouristRoutes?keyword=埃及&rating=largerThan2

https://localhost:7249/api/TouristRoutes?keyword=埃及&rating=largerThan4

封装资源过滤器

新建ResourceParameters文件夹 - TouristRouteResourceParamaters.cs

using System.Text.RegularExpressions;

namespace _01NET___CJ_ASP_Travel.ResourceParameters
{
    public class TouristRouteResourceParamaters
    {
        public string Keyword { get; set; }
        public string RatingOperator { get; set; }
        public int? RatingValue { get; set; }
        private string _rating;
        public string Rating
        {
            get { return _rating; }
            set
            {
                if (!string.IsNullOrWhiteSpace(value))
                {
                    Regex regex = new Regex(@"([A-Za-z0-9\-]+)(\d+)");
                    Match match = regex.Match(value);
                    if (match.Success)
                    {
                        RatingOperator = match.Groups[1].Value;
                        RatingValue = Int32.Parse(match.Groups[2].Value);
                    }
                }
                _rating = value;
            }
        }

    }
}

TouristRoutesController - GerTouristRoutes

        // api/touristRoutes?keyword=传入的参数
        [HttpGet]
        [HttpHead]
        public IActionResult GerTouristRoutes(
            [FromQuery] TouristRouteResourceParamaters paramaters
            /*[FromQuery] string keyword,
            string rating // 小于lessThan, 大于largerThan, 等于equalTo lessThan3, largerThan2, equalTo5 */
            ) // FromQuery vs FromBody
        {
            var touristRoutesFromRepo = _touristRouteRepository.GetTouristRoutes(paramaters.Keyword, paramaters.RatingOperator, paramaters.RatingValue);
            if (touristRoutesFromRepo == null || touristRoutesFromRepo.Count() <= 0)
            {
                return NotFound("没有旅游路线");
            }
            var touristRoutesDto = _mapper.Map<IEnumerable<TouristRouteDto>>(touristRoutesFromRepo);
            return Ok(touristRoutesDto);
        }

修改数据仓库GetTouristRoutes的传入参数

int? ratingValue

TouristRouteRepository同理

//返回一组旅游路线
               IEnumerable<TouristRoute> GetTouristRoutes(string keyword, string ratingOperator, int? ratingValue);

测试

https://localhost:7249/api/TouristRoutes?keyword=埃及&rating=largerThan2

七、【新建产品】POST 请求全面剖析

HTTP方法的安全性和幂等性

安全性

幂等性

同样的操作不管经过多少次调用，返回的数据、或者产生的效果都是一致的。

HTTP方法的安全性和幂等性

创建旅游路线资源

TouristRoutesController.cs

        // api/touristroutes/{touristRouteId}
        [HttpGet("{touristRouteId}", Name = "GetTouristRouteById")]
/*        [HttpHead]*/
        public IActionResult GetTouristRouteById(Guid touristRouteId)
        {
            var touristRouteFromRepo = _touristRouteRepository.GetTouristRoute(touristRouteId);
            if (touristRouteFromRepo == null)
            {
                return NotFound($"旅游路线{touristRouteId}找不到");
            }
            var touristRouteDto = _mapper.Map<TouristRouteDto>(touristRouteFromRepo);
            return Ok(touristRouteFromRepo);
        }

        [HttpPost]
        public IActionResult CreateTouristRoute([FromBody] TouristRouteForCreationDto touristRouteForCreationDto)
        {
            var touristRouteModel = _mapper.Map<TouristRoute>(touristRouteForCreationDto);
            _touristRouteRepository.AddTouristRoute(touristRouteModel);
            _touristRouteRepository.Save();
            var touristRouteToReture = _mapper.Map<TouristRouteDto>(touristRouteModel);
            return CreatedAtRoute(
                "GetTouristRouteById",
                new { touristRouteId = touristRouteToReture.Id },
                touristRouteToReture
            );
        }

创建新的DTO用于反序列化数据 - TouristRouteForCreationDto.cs

namespace _01NET___CJ_ASP_Travel.Dtos
{
    public class TouristRouteForCreationDto
    {
        public string Title { get; set; }
        public string Description { get; set; }
        // 计算方式：原价 * 折扣
        public decimal Price { get; set; }
        //public decimal OriginalPrice { get; set; }
        //public double? DiscountPresent { get; set; }
        public DateTime CreateTime { get; set; }
        public DateTime? UpdateTime { get; set; }
        public DateTime? DepartureTime { get; set; }
        public string Features { get; set; }
        public string Fees { get; set; }
        public string Notes { get; set; }
        public double? Rating { get; set; }
        public string TravelDays { get; set; }
        public string TripType { get; set; }
        public string DepartureCity { get; set; }
    }
}

TouristRouteProfile.cs

            CreateMap<TouristRouteForCreationDto, TouristRoute>()
                .ForMember(
                    dest => dest.Id,
                    opt => opt.MapFrom(src => Guid.NewGuid())
                );

新增接口函数(ITouristRouteRepository)

        void AddTouristRoute(TouristRoute touristRoute);
        bool Save();

TouristRouteRepository

        public void AddTouristRoute(TouristRoute touristRoute)
        {
            if (touristRoute == null)
            {
                throw new ArgumentNullException(nameof(touristRoute));
            }
            _context.TouristRoutes.Add(touristRoute);
            //_context.SaveChanges();
        }

        public bool Save()
        {
            return (_context.SaveChanges() >= 0);
        }

测试

{
    "title": "哈哈哈哈",
    "description": "哈哈哈哈",
     "originalPrice": 15490.00,
     "discountPercent": "0.9",
    "coupons": null,
    "points": 220
}

https://localhost:44381/api/TouristRoutes/0285b54e-8280-4e15-b62a-38c0738734df

即为他的请求

创建子资源：旅游路线图片

TouristRoutePicturesController.cs

        [HttpPost]
        public IActionResult CreateTouristRoutePicture(
            [FromRoute] Guid touristRouteId,
            [FromBody] TouristRoutePictureForCreationDto touristRoutePictureForCreationDto
        )
        {
            if (!_touristRouteRepository.TouristRouteExists(touristRouteId))
            {
                return NotFound("旅游线路不存在");
            }

            var pictureModel = _mapper.Map<TouristRoutePicture>(touristRoutePictureForCreationDto);
            _touristRouteRepository.AddTouristRoutePicture(touristRouteId, pictureModel);
            _touristRouteRepository.Save();
            var pictureToReturn = _mapper.Map<TouristRoutePictureDto>(pictureModel);
            return CreatedAtRoute(
                "GetPicture",
                new
                {
                    touristRouteId = pictureModel.TouristRouteId,
                    pictureId = pictureModel.Id
                },
                pictureToReturn
            );
        }

新建DTO - TouristRoutePictureForCreationDto.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace _02NET___CJ_ASP_Travel.Dtos
{
    public class TouristRoutePictureForCreationDto
    {
        public string Url { get; set; }
    }
}

TouristRoutePictureProfile.cs

namespace _02NET___CJ_ASP_Travel.Profiles
{
    public class TouristRoutePictureProfile: Profile
    {
        public TouristRoutePictureProfile()
        {
            CreateMap<TouristRoutePicture, TouristRoutePictureDto>();
            CreateMap<TouristRoutePictureForCreationDto, TouristRoutePicture>();
        }
    }
}

ITouristRouteRepository.cs

void AddTouristRoutePicture(Guid touristRouteId, TouristRoutePicture touristRoutePicture);

ITouristRouteRepository.cs

        public void AddTouristRoutePicture(Guid touristRouteId, TouristRoutePicture touristRoutePicture)
        {
            if (touristRouteId == Guid.Empty)
            {
                throw new ArgumentNullException(nameof(touristRouteId));
            }
            if (touristRoutePicture == null)
            {
                throw new ArgumentNullException(nameof(touristRoutePicture));
            }
            touristRoutePicture.TouristRouteId = touristRouteId;
            _context.TouristRoutePictures.Add(touristRoutePicture);
        }

同时创建父子资源

TouristRouteForCreationDto.cs

        public ICollection<TouristRoutePictureForCreationDto> TouristRoutePictures { get; set; }
    = new List<TouristRoutePictureForCreationDto>();

ASP.NET Core 的数据验证

制定一个合理的数据检验规则。
检测数据。
提交错误信息。

制定数据检验规则

检测数据

提交错误信息

添加数据验证

TouristRouteForCreationDto.cs

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

namespace _02NET___CJ_ASP_Travel.Dtos
{
    public class TouristRouteForCreationDto
    {
        [Required(ErrorMessage = "title 不可为空")]
        [MaxLength(100)]
        public string Title { get; set; }

        [Required]
        [MaxLength(1500)]
        public string Description { get; set; }
        // 计算方式：原价 * 折扣
        public decimal Price { get; set; }
        //public decimal OriginalPrice { get; set; }
        //public double? DiscountPresent { get; set; }
        public DateTime CreateTime { get; set; }
        public DateTime? UpdateTime { get; set; }
        public DateTime? DepartureTime { get; set; }
        public string Features { get; set; }
        public string Fees { get; set; }
        public string Notes { get; set; }
        public double? Rating { get; set; }
        public string TravelDays { get; set; }
        public string TripType { get; set; }
        public string DepartureCity { get; set; }

        public ICollection<TouristRoutePictureForCreationDto> TouristRoutePictures { get; set; }
    = new List<TouristRoutePictureForCreationDto>();

        public IEnumerable<ValidationResult> Validate(
    ValidationContext validationContext)
        {
            if (Title == Description)
            {
                yield return new ValidationResult(
                    "路线名称必须与路线描述不同",
                    new[] { "TouristRouteForCreationDto" }
                );
            }
        }
    }
}

属性级别数据验证

（TouristRouteForCreationDto.cs）使用接口

public class TouristRouteForCreationDto : IValidatableObject

类级别数据验证

新建ValidationAttributes文件夹 - TouristRouteTitleMustBeDifferentFromDescriptionAttribute.cs

using _02NET___CJ_ASP_Travel.Dtos;
using System.ComponentModel.DataAnnotations;

namespace _02NET___CJ_ASP_Travel.ValidationAttributes
{
    public class TouristRouteTitleMustBeDifferentFromDescriptionAttribute : ValidationAttribute
    {
        protected override ValidationResult IsValid(
            object value,
            ValidationContext validationContext
        )
        {
            var touristRouteDto = (TouristRouteForCreationDto)validationContext.ObjectInstance;
            if (touristRouteDto.Title == touristRouteDto.Description)
            {
                return new ValidationResult(
                    "路线名称必须与路线描述不同",
                    new[] { "TouristRouteForCreationDto" }
                );
            }
            return ValidationResult.Success;
        }
    }
}

TouristRouteForCreationDto

   [TouristRouteTitleMustBeDifferentFromDescriptionAttribute]

输出状态码 422

Startup.cs

.ConfigureApiBehaviorOptions

public void ConfigureServices(IServiceCollection services)
        {
            services.AddControllers(setupAction => {
                setupAction.ReturnHttpNotAcceptable = true;
                //setupAction.OutputFormatters.Add(
                //    new XmlDataContractSerializerOutputFormatter()    
                //);
            }).AddXmlDataContractSerializerFormatters()
            .ConfigureApiBehaviorOptions(setupAction =>
            {
                setupAction.InvalidModelStateResponseFactory = context =>
                {
                    var problemDetail = new ValidationProblemDetails(context.ModelState)
                    {
                        Type = "无所谓",
                        Title = "数据验证失败",
                        Status = StatusCodes.Status422UnprocessableEntity,
                        Detail = "请看详细说明",
                        Instance = context.HttpContext.Request.Path
                    };
                    problemDetail.Extensions.Add("traceId", context.HttpContext.TraceIdentifier);
                    return new UnprocessableEntityObjectResult(problemDetail)
                    {
                        ContentTypes = { "application/problem+json" }
                    };
                };
            });

            //省略------------------------
        }

八、【更新产品】PUT vs POST

PUT vs. PATCH

数据更新

PUT ?or? PATCH

使用put请求更新资源

TouristRoutesController.cs

        [HttpPut("{touristRouteId}")]
        public IActionResult UpdateTouristRoute(
            [FromRoute]Guid touristRouteId,
            [FromBody] TouristRouteForUpdateDto touristRouteForUpdateDto
        )
        {
            if (!_touristRouteRepository.TouristRouteExists(touristRouteId))
            {
                return NotFound("旅游路线找不到");
            }

            var touristRouteFromRepo = _touristRouteRepository.GetTouristRoute(touristRouteId);
            // 1. 映射dto
            // 2. 更新dto
            // 3. 映射model
            _mapper.Map(touristRouteForUpdateDto, touristRouteFromRepo);

            _touristRouteRepository.Save();

            return NoContent();
        }

Dto - TouristRouteForUpdateDto.cs

using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Threading.Tasks;
using _02NET___CJ_ASP_Travel.Dtos;

namespace _02NET___CJ_ASP_Travel.Dtos
{
    public class TouristRouteForUpdateDto
    {
        [Required(ErrorMessage = "title 不可为空")]
        [MaxLength(100)]
        public string Title { get; set; }
        [Required]
        [MaxLength(1500)]
        public string Description { get; set; }
        // 计算方式：原价 * 折扣
        public decimal Price { get; set; }
        //public decimal OriginalPrice { get; set; }
        //public double? DiscountPresent { get; set; }
        public DateTime CreateTime { get; set; }
        public DateTime? UpdateTime { get; set; }
        public DateTime? DepartureTime { get; set; }
        public string Features { get; set; }
        public string Fees { get; set; }
        public string Notes { get; set; }
        public double? Rating { get; set; }
        public string TravelDays { get; set; }
        public string TripType { get; set; }
        public string DepartureCity { get; set; }
        public ICollection<TouristRoutePictureForCreationDto> TouristRoutePictures { get; set; }
            = new List<TouristRoutePictureForCreationDto>();
    }
}

PUT请求的数据验证

修改TouristRouteForUpdateDto.cs

using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Threading.Tasks;
using _02NET___CJ_ASP_Travel.Dtos;

namespace _02NET___CJ_ASP_Travel.Dtos
{
    public class TouristRouteForUpdateDto : TouristRouteForManipulationDto
    {
        [Required(ErrorMessage = "更新必备")]
        [MaxLength(1500)]
        public override string Description { get; set; }
    }
}

新建父类TouristRouteForManipulationDto.cs

using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Threading.Tasks;
using _02NET___CJ_ASP_Travel.ValidationAttributes;

namespace _02NET___CJ_ASP_Travel.Dtos
{
    [TouristRouteTitleMustBeDifferentFromDescriptionAttribute]
    public abstract class TouristRouteForManipulationDto
    {
        [Required(ErrorMessage = "title 不可为空")]
        [MaxLength(100)]
        public string Title { get; set; }
        [Required]
        [MaxLength(1500)]
        public virtual string Description { get; set; }
        // 计算方式：原价 * 折扣
        public decimal Price { get; set; }
        //public decimal OriginalPrice { get; set; }
        //public double? DiscountPresent { get; set; }
        public DateTime CreateTime { get; set; }
        public DateTime? UpdateTime { get; set; }
        public DateTime? DepartureTime { get; set; }
        public string Features { get; set; }
        public string Fees { get; set; }
        public string Notes { get; set; }
        public double? Rating { get; set; }
        public string TravelDays { get; set; }
        public string TripType { get; set; }
        public string DepartureCity { get; set; }
        public ICollection<TouristRoutePictureForCreationDto> TouristRoutePictures { get; set; }
            = new List<TouristRoutePictureForCreationDto>();

    }
}

TouristRouteForCreationDto.cs也继承TouristRouteForManipulationDto

public class TouristRouteForCreationDto : TouristRouteForManipulationDto

资源的局部更新PATCH

PATCH请求的主体 —— JSON Patch（JSON补丁文档）

JSON Patch操作

使用PATCH部分更新资源

TouristRoutesController.cs

        [HttpPatch("{touristRouteId}")]
        public IActionResult PartiallyUpdateTouristRoute(
            [FromRoute]Guid touristRouteId,
            [FromBody] JsonPatchDocument<TouristRouteForUpdateDto> patchDocument
        )
        {
            if (!_touristRouteRepository.TouristRouteExists(touristRouteId))
            {
                return NotFound("旅游路线找不到");
            }

            var touristRouteFromRepo = _touristRouteRepository.GetTouristRoute(touristRouteId);
            var touristRouteToPatch = _mapper.Map<TouristRouteForUpdateDto>(touristRouteFromRepo);
            patchDocument.ApplyTo(touristRouteToPatch);

            _mapper.Map(touristRouteToPatch, touristRouteFromRepo);
            _touristRouteRepository.Save();

            return NoContent();
        }

配置nuget

microsoft.aspnetcore.jsonpatch

Microsoft.AspNetCore.Mvc.NewtonsoftJson

TouristRouteProfile.cs

            CreateMap<TouristRouteForUpdateDto, TouristRoute>();

            CreateMap<TouristRoute, TouristRouteForUpdateDto>();

TouristRoutePictureProfile.cs

            CreateMap<TouristRoutePicture, TouristRoutePictureForCreationDto>();

引用NewtonsoftJson框架

Startup.cs

   //新增部分         .AddNewtonsoftJson(setupAction => {
                setupAction.SerializerSettings.ContractResolver =
                    new CamelCasePropertyNamesContractResolver();

   //完整部分 
public void ConfigureServices(IServiceCollection services)
        {
            services.AddControllers(setupAction => {
                setupAction.ReturnHttpNotAcceptable = true;
            })
            .AddNewtonsoftJson(setupAction => {
                setupAction.SerializerSettings.ContractResolver =
                    new CamelCasePropertyNamesContractResolver();
            }).AddXmlDataContractSerializerFormatters()
            .ConfigureApiBehaviorOptions(setupAction =>
            {
                setupAction.InvalidModelStateResponseFactory = context =>
                {
                    var problemDetail = new ValidationProblemDetails(context.ModelState)
                    {
                        Type = "无所谓",
                        Title = "数据验证失败",
                        Status = StatusCodes.Status422UnprocessableEntity,
                        Detail = "请看详细说明",
                        Instance = context.HttpContext.Request.Path
                    };
                    problemDetail.Extensions.Add("traceId", context.HttpContext.TraceIdentifier);
                    return new UnprocessableEntityObjectResult(problemDetail)
                    {
                        ContentTypes = { "application/problem+json" }
                    };
                };
            });

            //注册数据仓库的服务依赖
            //以下三个Add都可以用于依赖注入
            //services.AddSingleton
            //services.AddScoped
            services.AddTransient<ITouristRouteRepository, TouristRouteRepository>();

            /*            数据库映射*/
            services.AddDbContext<AppDbContext>(options => {
                options.UseSqlServer(Configuration["DbContext:ConnectionString"]);
            });

            // 扫描profile文件
            services.AddAutoMapper(AppDomain.CurrentDomain.GetAssemblies());
        }

PATCH请求的数据验证

ASP数据验证：ModelState

            if (!TryValidateModel(touristRouteToPatch))
            {
                return ValidationProblem(ModelState);
            }

完整代码

        [HttpPatch("{touristRouteId}")]
        public IActionResult PartiallyUpdateTouristRoute(
            [FromRoute]Guid touristRouteId,
            [FromBody] JsonPatchDocument<TouristRouteForUpdateDto> patchDocument
        )
        {
            if (!_touristRouteRepository.TouristRouteExists(touristRouteId))
            {
                return NotFound("旅游路线找不到");
            }

            var touristRouteFromRepo = _touristRouteRepository.GetTouristRoute(touristRouteId);
            var touristRouteToPatch = _mapper.Map<TouristRouteForUpdateDto>(touristRouteFromRepo);
            patchDocument.ApplyTo(touristRouteToPatch, ModelState);
            if (!TryValidateModel(touristRouteToPatch))
            {
                return ValidationProblem(ModelState);
            }
            _mapper.Map(touristRouteToPatch, touristRouteFromRepo);
            _touristRouteRepository.Save();

            return NoContent();
        }

九、【删除产品】解读http Delete

删除资源

TouristRoutesController.cs

        [HttpDelete("{touristRouteId}")]
        public IActionResult DeleteTouristRoute([FromRoute] Guid touristRouteId)
        {
            if (!_touristRouteRepository.TouristRouteExists(touristRouteId))
            {
                return NotFound("旅游路线找不到");
            }

            var touristRoute = _touristRouteRepository.GetTouristRoute(touristRouteId);
            _touristRouteRepository.DeleteTouristRoute(touristRoute);
            _touristRouteRepository.Save();

            return NoContent();
        }

新增接口函数（ITouristRouteRepository.cs）

        void DeleteTouristRoute(TouristRoute touristRoute);

TouristRouteRepository.cs

        public void DeleteTouristRoute(TouristRoute touristRoute)
        {
            _context.TouristRoutes.Remove(touristRoute);
        }

删除嵌套子资源

TouristRoutePicturesController.cs

        [HttpDelete("{pictureId}")]
        public IActionResult DeletePicture(
            [FromRoute]Guid touristRouteId, 
            [FromRoute]int pictureId
        )
        {
            if (!_touristRouteRepository.TouristRouteExists(touristRouteId))
            {
                return NotFound("旅游线路不存在");
            }

            var picture = _touristRouteRepository.GetPicture(pictureId);
            _touristRouteRepository.DeleteTouristRoutePicture(picture);
            _touristRouteRepository.Save();

            return NoContent();
        }

新增接口函数（ITouristRouteRepository.cs）

        void DeleteTouristRoutePicture(TouristRoutePicture picture);

TouristRouteRepository.cs

        public void DeleteTouristRoutePicture(TouristRoutePicture picture)
        {
            _context.TouristRoutePictures.Remove(picture);
        }

批量删除资源

TouristRouteController.cs

        [HttpDelete("({touristIDs})")]
        public IActionResult DeleteByIDs(
            [ModelBinder( BinderType = typeof(ArrayModelBinder))][FromRoute]IEnumerable<Guid> touristIDs)
        {
            if(touristIDs == null)
            {
                return BadRequest();
            }

            var touristRoutesFromRepo = _touristRouteRepository.GetTouristRoutesByIDList(touristIDs);
            _touristRouteRepository.DeleteTouristRoutes(touristRoutesFromRepo);
            _touristRouteRepository.Save();

            return NoContent();
        }

新建工具类文件夹Helper

ArrayModelBinder.cs

using Microsoft.AspNetCore.Mvc.ModelBinding;
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Reflection;
using System.Threading.Tasks;

namespace _02NET___CJ_ASP_Travel.Helper
{
    public class ArrayModelBinder : IModelBinder
    {
        public Task BindModelAsync(ModelBindingContext bindingContext)
        {
            // Our binder works only on enumerable types
            if (!bindingContext.ModelMetadata.IsEnumerableType)
            {
                bindingContext.Result = ModelBindingResult.Failed();
                return Task.CompletedTask;
            }

            // Get the inputted value through the value provider
            var value = bindingContext.ValueProvider
                .GetValue(bindingContext.ModelName).ToString();

            // If that value is null or whitespace, we return null
            if (string.IsNullOrWhiteSpace(value))
            {
                bindingContext.Result = ModelBindingResult.Success(null);
                return Task.CompletedTask;
            }

            // The value isn't null or whitespace, 
            // and the type of the model is enumerable. 
            // Get the enumerable's type, and a converter 
            var elementType = bindingContext.ModelType.GetTypeInfo().GenericTypeArguments[0];
            var converter = TypeDescriptor.GetConverter(elementType);

            // Convert each item in the value list to the enumerable type
            var values = value.Split(new[] { "," }, StringSplitOptions.RemoveEmptyEntries)
                .Select(x => converter.ConvertFromString(x.Trim()))
                .ToArray();

            // Create an array of that type, and set it as the Model value 
            var typedValues = Array.CreateInstance(elementType, values.Length);
            values.CopyTo(typedValues, 0);
            bindingContext.Model = typedValues;

            // return a successful result, passing in the Model 
            bindingContext.Result = ModelBindingResult.Success(bindingContext.Model);
            return Task.CompletedTask;
        }
    }

}

新增接口函数（ITouristRouteRepository.cs）

IEnumerable<TouristRoute> GetTouristRoutesByIDList(IEnumerable<Guid> ids);

        void DeleteTouristRoutes(IEnumerable<TouristRoute> touristRoutes);

接口实现TouristRouteRepository.cs

        public IEnumerable<TouristRoute> GetTouristRoutesByIDList(IEnumerable<Guid> ids)
        {
            return _context.TouristRoutes.Where(t => ids.Contains(t.Id)).ToList();
        }

        public void DeleteTouristRoutes(IEnumerable<TouristRoute> touristRoutes)
        {
            _context.TouristRoutes.RemoveRange(touristRoutes);
        }

十、【项目重构】异步async/await

项目存在的问题

解决方案 - 异步操作

百万级请求的处理

C#的异步async /await

同步方法

指程序调用某个方法，需要等待执行完成以后才进行下一步操作。

异步方法

指程序调用某个方法的时候，不做任何等待等待，在处理完成之前就返回该方法，继续执行接下来的操作。

异步方法是什么？

函数在执行完成前就可以先返回调用方，然后继续执行
的接下来的逻辑完成任务的函数。

代码示例

异步控制的流程

在函数声明中使用async关键词的意义是什么呢？

总结

项目重构异步模式

修改ITouristRouteRepository.cs

在接口前加上Task。
函数名后+Async，例如GetTouristRoute命名为GetTouristRouteAsync

using _02NET___CJ_ASP_Travel.Models;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;


namespace _02NET___CJ_ASP_Travel.Services
{
    public interface ITouristRouteRepository
    {
        //返回一组旅游路线
        Task<IEnumerable<TouristRoute>> GetTouristRoutesAsync(string keyword, string ratingOperator, int? ratingValue);

        //返回单独的旅游路线
        Task<TouristRoute> GetTouristRouteAsync(Guid touristRouteId);
        Task<bool> TouristRouteExistsAsync(Guid touristRouteId);
        Task<IEnumerable<TouristRoutePicture>> GetPicturesByTouristRouteIdAsync(Guid touristRouteId);
        Task<TouristRoutePicture> GetPictureAsync(int pictureId);
        Task<IEnumerable<TouristRoute>> GetTouristRoutesByIDListAsync(IEnumerable<Guid> ids);
        void AddTouristRoute(TouristRoute touristRoute);
        void AddTouristRoutePicture(Guid touristRouteId, TouristRoutePicture touristRoutePicture);
        void DeleteTouristRoute(TouristRoute touristRoute);
        void DeleteTouristRoutes(IEnumerable<TouristRoute> touristRoutes);
        void DeleteTouristRoutePicture(TouristRoutePicture picture);
        Task<bool> SaveAsync();
    }
}

TouristRouteRepository.cs

加上关键词async Task
函数名后+Async，例如GetTouristRoute命名为GetTouristRouteAsync
FirstOrDefault();修改为FirstOrDefaultAsync();，即加上Async。
return await

using _02NET___CJ_ASP_Travel.Database;
using _02NET___CJ_ASP_Travel.Models;
using Microsoft.EntityFrameworkCore;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace _02NET___CJ_ASP_Travel.Services
{
    public class TouristRouteRepository : ITouristRouteRepository
    {
        private readonly AppDbContext _context;

        public TouristRouteRepository(AppDbContext appDbContext)
        {
            _context = appDbContext;
        }

        public async Task<TouristRoute> GetTouristRouteAsync(Guid touristRouteId)
        {
            return await _context.TouristRoutes.Include(t => t.TouristRoutePictures).FirstOrDefaultAsync(n => n.Id == touristRouteId);
        }

        public async Task<IEnumerable<TouristRoute>> GetTouristRoutesAsync(
            string keyword,
            string ratingOperator,
            int? ratingValue
        )
        {
            IQueryable<TouristRoute> result = _context
                .TouristRoutes
                .Include(t => t.TouristRoutePictures);
            if (!string.IsNullOrWhiteSpace(keyword))
            {
                keyword = keyword.Trim();
                result = result.Where(t => t.Title.Contains(keyword));
            }
            if (ratingValue >= 0)
            {
                result = ratingOperator switch
                {
                    "largerThan" => result.Where(t => t.Rating >= ratingValue),
                    "lessThan" => result.Where(t => t.Rating <= ratingValue),
                    _ => result.Where(t => t.Rating == ratingValue),
                };
            }
            // include vs join
            return await result.ToListAsync();
        }

        public async Task<bool> TouristRouteExistsAsync(Guid touristRouteId)
        {
            return await _context.TouristRoutes.AnyAsync(t => t.Id == touristRouteId);
        }

        public async Task<IEnumerable<TouristRoutePicture>> GetPicturesByTouristRouteIdAsync(Guid touristRouteId)
        {
            return await _context.TouristRoutePictures
                .Where(p => p.TouristRouteId == touristRouteId).ToListAsync();
        }

        public async Task<TouristRoutePicture> GetPictureAsync(int pictureId)
        {
            return await _context.TouristRoutePictures.Where(p => p.Id == pictureId).FirstOrDefaultAsync();
        }

        public async Task<IEnumerable<TouristRoute>> GetTouristRoutesByIDListAsync(IEnumerable<Guid> ids)
        {
            return await _context.TouristRoutes.Where(t => ids.Contains(t.Id)).ToListAsync();
        }

        public void AddTouristRoute(TouristRoute touristRoute)
        {
            if (touristRoute == null)
            {
                throw new ArgumentNullException(nameof(touristRoute));
            }
            _context.TouristRoutes.Add(touristRoute);
            //_context.SaveChanges();
        }

        public void AddTouristRoutePicture(Guid touristRouteId, TouristRoutePicture touristRoutePicture)
        {
            if (touristRouteId == Guid.Empty)
            {
                throw new ArgumentNullException(nameof(touristRouteId));
            }
            if (touristRoutePicture == null)
            {
                throw new ArgumentNullException(nameof(touristRoutePicture));
            }
            touristRoutePicture.TouristRouteId = touristRouteId;
            _context.TouristRoutePictures.Add(touristRoutePicture);
        }

        public void DeleteTouristRoute(TouristRoute touristRoute)
        {
            _context.TouristRoutes.Remove(touristRoute);
        }

        public void DeleteTouristRoutePicture(TouristRoutePicture picture)
        {
            _context.TouristRoutePictures.Remove(picture);
        }

        public void DeleteTouristRoutes(IEnumerable<TouristRoute> touristRoutes)
        {
            _context.TouristRoutes.RemoveRange(touristRoutes);
        }

        public async Task<bool> SaveAsync()
        {
            return (await _context.SaveChangesAsync() >= 0);
        }
    }
}

TouristRoutePicturesController.cs

using _02NET___CJ_ASP_Travel.Dtos;
using _02NET___CJ_ASP_Travel.Models;
using _02NET___CJ_ASP_Travel.Services;
using AutoMapper;
using Microsoft.AspNetCore.Mvc;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace _02NET___CJ_ASP_Travel.Controllers
{
    [Route("api/touristRoutes/{touristRouteId}/pictures")]
    [ApiController]
    public class TouristRoutePicturesController : ControllerBase
    {
        private ITouristRouteRepository _touristRouteRepository;
        private IMapper _mapper;

        public TouristRoutePicturesController(
            ITouristRouteRepository touristRouteRepository,
            IMapper mapper
        )
        {
            _touristRouteRepository = touristRouteRepository ??
                throw new ArgumentNullException(nameof(touristRouteRepository));
            _mapper = mapper ??
                throw new ArgumentNullException(nameof(mapper));
        }

        [HttpGet]
        public async Task<IActionResult> GetPictureListForTouristRoute(Guid touristRouteId)
        {
            if (!(await _touristRouteRepository.TouristRouteExistsAsync(touristRouteId)))
            {
                return NotFound("旅游线路不存在");
            }

            var picturesFromRepo = await _touristRouteRepository.GetPicturesByTouristRouteIdAsync(touristRouteId);
            if (picturesFromRepo == null || picturesFromRepo.Count() <= 0)
            {
                return NotFound("照片不存在");
            }

            return Ok(_mapper.Map<IEnumerable<TouristRoutePictureDto>>(picturesFromRepo));

        }

        [HttpGet("{pictureId}", Name = "GetPicture")]
        public async Task<IActionResult> GetPicture(Guid touristRouteId, int pictureId)
        {
            if (!(await _touristRouteRepository.TouristRouteExistsAsync(touristRouteId)))
            {
                return NotFound("旅游线路不存在");
            }

            var pictureFromRepo = await _touristRouteRepository.GetPictureAsync(pictureId);
            if (pictureFromRepo == null)
            {
                return NotFound("相片不存在");
            }
            return Ok(_mapper.Map<TouristRoutePictureDto>(pictureFromRepo));
        }

        [HttpPost]
        public async Task<IActionResult> CreateTouristRoutePicture(
            [FromRoute] Guid touristRouteId,
            [FromBody] TouristRoutePictureForCreationDto touristRoutePictureForCreationDto
        )
        {
            if (!(await _touristRouteRepository.TouristRouteExistsAsync(touristRouteId)))
            {
                return NotFound("旅游线路不存在");
            }

            var pictureModel = _mapper.Map<TouristRoutePicture>(touristRoutePictureForCreationDto);
            _touristRouteRepository.AddTouristRoutePicture(touristRouteId, pictureModel);
            await _touristRouteRepository.SaveAsync();
            var pictureToReturn = _mapper.Map<TouristRoutePictureDto>(pictureModel);
            return CreatedAtRoute(
                "GetPicture",
                new
                {
                    touristRouteId = pictureModel.TouristRouteId,
                    pictureId = pictureModel.Id
                },
                pictureToReturn
            );
        }

        [HttpDelete("{pictureId}")]
        public async Task<IActionResult> DeletePicture(
            [FromRoute] Guid touristRouteId,
            [FromRoute] int pictureId
        )
        {
            if (!(await _touristRouteRepository.TouristRouteExistsAsync(touristRouteId)))
            {
                return NotFound("旅游线路不存在");
            }

            var picture = await _touristRouteRepository.GetPictureAsync(pictureId);
            _touristRouteRepository.DeleteTouristRoutePicture(picture);
            await _touristRouteRepository.SaveAsync();

            return NoContent();
        }
    }
}

TouristRouteController.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using AutoMapper;
using System.Text.RegularExpressions;
using Microsoft.AspNetCore.JsonPatch;
using _02NET___CJ_ASP_Travel.Dtos;
using _02NET___CJ_ASP_Travel.Models;
using _02NET___CJ_ASP_Travel.ResourceParameters;
using _02NET___CJ_ASP_Travel.Services;
using _02NET___CJ_ASP_Travel.Helper;

namespace _02NET___CJ_ASP_Travel.Controllers
{
    [Route("api/[controller]")] // api/touristroute
    [ApiController]
    public class TouristRoutesController : ControllerBase
    {
        private ITouristRouteRepository _touristRouteRepository;
        private readonly IMapper _mapper;

        public TouristRoutesController(
            ITouristRouteRepository touristRouteRepository,
            IMapper mapper
        )
        {
            _touristRouteRepository = touristRouteRepository;
            _mapper = mapper;
        }

        // api/touristRoutes?keyword=传入的参数
        [HttpGet]
        [HttpHead]
        public async Task<IActionResult> GerTouristRoutes(
            [FromQuery] TouristRouteResourceParamaters paramaters
        //[FromQuery] string keyword,
        //string rating // 小于lessThan, 大于largerThan, 等于equalTo lessThan3, largerThan2, equalTo5 
        )// FromQuery vs FromBody
        {
            var touristRoutesFromRepo = await _touristRouteRepository.GetTouristRoutesAsync(paramaters.Keyword, paramaters.RatingOperator, paramaters.RatingValue);
            if (touristRoutesFromRepo == null || touristRoutesFromRepo.Count() <= 0)
            {
                return NotFound("没有旅游路线");
            }
            var touristRoutesDto = _mapper.Map<IEnumerable<TouristRouteDto>>(touristRoutesFromRepo);
            return Ok(touristRoutesDto);
        }

        // api/touristroutes/{touristRouteId}
        [HttpGet("{touristRouteId}", Name = "GetTouristRouteById")]
        public async Task<IActionResult> GetTouristRouteById(Guid touristRouteId)
        {
            var touristRouteFromRepo = await _touristRouteRepository.GetTouristRouteAsync(touristRouteId);
            if (touristRouteFromRepo == null)
            {
                return NotFound($"旅游路线{touristRouteId}找不到");
            }

            var touristRouteDto = _mapper.Map<TouristRouteDto>(touristRouteFromRepo);
            return Ok(touristRouteDto);
        }

        [HttpPost]
        public async Task<IActionResult> CreateTouristRoute([FromBody] TouristRouteForCreationDto touristRouteForCreationDto)
        {
            var touristRouteModel = _mapper.Map<TouristRoute>(touristRouteForCreationDto);
            _touristRouteRepository.AddTouristRoute(touristRouteModel);
            await _touristRouteRepository.SaveAsync();
            var touristRouteToReture = _mapper.Map<TouristRouteDto>(touristRouteModel);
            return CreatedAtRoute(
                "GetTouristRouteById",
                new { touristRouteId = touristRouteToReture.Id },
                touristRouteToReture
            );
        }

        [HttpPut("{touristRouteId}")]
        public async Task<IActionResult> UpdateTouristRoute(
            [FromRoute] Guid touristRouteId,
            [FromBody] TouristRouteForUpdateDto touristRouteForUpdateDto
        )
        {
            if (!(await _touristRouteRepository.TouristRouteExistsAsync(touristRouteId)))
            {
                return NotFound("旅游路线找不到");
            }

            var touristRouteFromRepo = await _touristRouteRepository.GetTouristRouteAsync(touristRouteId);
            // 1. 映射dto
            // 2. 更新dto
            // 3. 映射model
            _mapper.Map(touristRouteForUpdateDto, touristRouteFromRepo);

            await _touristRouteRepository.SaveAsync();

            return NoContent();
        }

        [HttpPatch("{touristRouteId}")]
        public async Task<IActionResult> PartiallyUpdateTouristRoute(
            [FromRoute] Guid touristRouteId,
            [FromBody] JsonPatchDocument<TouristRouteForUpdateDto> patchDocument
        )
        {
            if (!(await _touristRouteRepository.TouristRouteExistsAsync(touristRouteId)))
            {
                return NotFound("旅游路线找不到");
            }

            var touristRouteFromRepo = await _touristRouteRepository.GetTouristRouteAsync(touristRouteId);
            var touristRouteToPatch = _mapper.Map<TouristRouteForUpdateDto>(touristRouteFromRepo);
            patchDocument.ApplyTo(touristRouteToPatch, ModelState);
            if (!TryValidateModel(touristRouteToPatch))
            {
                return ValidationProblem(ModelState);
            }
            _mapper.Map(touristRouteToPatch, touristRouteFromRepo);
            await _touristRouteRepository.SaveAsync();

            return NoContent();
        }

        [HttpDelete("{touristRouteId}")]
        public async Task<IActionResult> DeleteTouristRoute([FromRoute] Guid touristRouteId)
        {
            if (!(await _touristRouteRepository.TouristRouteExistsAsync(touristRouteId)))
            {
                return NotFound("旅游路线找不到");
            }

            var touristRoute = await _touristRouteRepository.GetTouristRouteAsync(touristRouteId);
            _touristRouteRepository.DeleteTouristRoute(touristRoute);
            await _touristRouteRepository.SaveAsync();

            return NoContent();
        }

        [HttpDelete("({touristIDs})")]
        public async Task<IActionResult> DeleteByIDs(
            [ModelBinder(BinderType = typeof(ArrayModelBinder))][FromRoute] IEnumerable<Guid> touristIDs)
        {
            if (touristIDs == null)
            {
                return BadRequest();
            }

            var touristRoutesFromRepo = await _touristRouteRepository.GetTouristRoutesByIDListAsync(touristIDs);
            _touristRouteRepository.DeleteTouristRoutes(touristRoutesFromRepo);
            await _touristRouteRepository.SaveAsync();

            return NoContent();
        }
    }
}

C# - 基于.NetCore开发的“寸金游”（后端开发）

一、前情提要

模块 or 架构

RESTful成熟度模型

二、【项目启动】ASP.Net Core API 上手指南

.Net Core的前世今生

Asp.Net Core MVC

创建实战项目

下载.Net6

CMD中输入dotnet --version测试.Net是否安装成功

配置VS工作负荷ASP.NET

创建Hello World项目

新建项目ASP.NET Core Web应用

运行测试

选择IIS服务器 或者 本地服务器

.NET Core的中间件、请求通道、以及环境设置

请求通道Request Pipeline

中间件Middelware

添加第一个API

注册MVC的框架依赖（Startup.cs）

新建Controllers文件夹

建立API控制器类TestApiController.cs

访问https://localhost:7249/api/testapi

请求成功

新建ShoudongAPI.cs

访问https://localhost:7249/api/shoudongapi

普通的类文件如何识别为控制器类

MVC架构

ASP.NET Core MVC框架

什么是MVC

视图View

模型Model

控制器Controller

MVC架构的数据是如何流动？

MVC的优点

三、【数据构建】数据模型与数据库设计

商城数据模型设计

数据模型设计指南

正确的项目启动思路

业务线（DDD）

根据业务模块建立数据模型

ER关系

逻辑 or 物理概念

数据模型与仓库模式

数据模型的作用

代码示例

如何从数据库中获取数据呢？

repository仓库模式

Model的文件结构

使用模型和数据仓库的好处

面向对象编程

创建数据模型和数据仓库

新建Models文件夹

创建数据模型

新增TouristRoute.cs类

新增TouristRoutePicture.cs

建立数据仓库

新建Services文件夹

新建接口（interface）ITouristRouteRepository

新建类 （Mock假数据）MockTouristRouteRepository

Startup.cs

注册数据仓库的服务依赖

通过Api展示数据

Controllers - TouristRoutesController.cs

API控制器

测试

输入https://localhost:7249/api/TouristRoutes

什么是Entity Framework

Entity Framework Core

EF的组件

添加Entity Framework Core

新建Database文件夹

数据库映射工具AppDbContext.cs

Startup.cs

安装包Microsoft.EntityFrameworkCore.SqlServer

在appsettings.json中配置数据库连接字符串

ConnectionString

Services - TouristRouteRepository.cs

创建数据库

使用EntityFramework创建数据库

CMD中输入`dotnet --version`测试.Net是否安装成功

选择IIS服务器或者本地服务器

新建类（Mock假数据）MockTouristRouteRepository

Richardson四个级别的成熟度模型与 HATOAS

修改GetTouristRouteById方法和 GetTouristRoutes方法（TouristRoutesController.cs）