《Asp.Net Core3 + Vue3入坑教程》 - 3.AutoMapper & Restful API & DI
简介
《Asp.Net Core3 + Vue3入坑教程》 此教程适合新手入门或者前后端分离尝试者。可以根据图文一步一步进操作编码也可以选择直接查看源码。每一篇文章都有对应的源码
教程后期会将 .Net Core 3升级成 .Net Core 5
目录
《Asp.Net Core3 + Vue3入坑教程》系列教程目录
Asp.Net Core后端项目
- 后端项目搭建与Swagger配置步骤
- 配置CROS策略解决跨域问题
- (本文)AutoMapper & Restful API & DI
- EF Core & Postgresql
- (暂未发表敬请期待...).Net Core 3升级成 .Net Core 5
- (暂未发表敬请期待...)JWT
Vue3 前端项目
暂未发表敬请期待...
本文简介
本文为《Asp.Net Core3 + Vue3入坑教程》系列教程的后端第三篇 - AutoMapper & Restful API & DI。本文将利用AutoMapper与依赖注入等内容实现一个简单的Restful API。
实现一个简单的Restful API
引入NewtonsoftJson3.1.12版本的Nuget包
当前项目使用的SKD是 .net core 3后续将SDK升级之后再升级此Nuget包的版本
配置Startup.cs
代码如下:
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Newtonsoft.Json.Serialization;
using Simple_Asp.Net_Core.Data;
using Simple_Asp.Net_Core.ServiceProvider;
using System;
namespace Simple_Asp.Net_Core
{
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.AddCORS();
services.AddMvc();
services.AddSwagger();
services.AddControllers().AddNewtonsoftJson(s =>
{
s.SerializerSettings.ContractResolver = new CamelCasePropertyNamesContractResolver();
});
}
// 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.UseSwagger();
app.UseSwaggerUI(c =>
{
c.SwaggerEndpoint("/swagger/v1/swagger.json", "ApiHelp V1");
});
}
app.UseCors("CorsTest");
app.UseRouting();
app.UseEndpoints(endpoints => endpoints.MapDefaultControllerRoute());
}
}
}
新建文件夹Models,新建实体Command.cs
代码如下:
using System.ComponentModel.DataAnnotations;
namespace Simple_Asp.Net_Core.Models
{
public class Command
{
[Key]
[Required]
public int Id { get; set; }
[Required]
[MaxLength(250)]
public string HowTo { get; set; }
[Required]
public string Line { get; set; }
[Required]
public string Platform { get; set; }
}
}
新建Data文件夹 新建 ICommanderRepo 仓储层接口,用来定义与数据库交互的接口
using Simple_Asp.Net_Core.Models;
using System.Collections.Generic;
namespace Simple_Asp.Net_Core.Data
{
public interface ICommanderRepo
{
IEnumerable<Command> GetAllCommands();
}
}
现在我们还没有数据库,就先模拟数据返回!新建MockCommanderRepo.cs来实现ICommanderRepo接口
using Simple_Asp.Net_Core.Models;
using System.Collections.Generic;
namespace Simple_Asp.Net_Core.Data
{
public class MockCommanderRepo : ICommanderRepo
{
public IEnumerable<Command> GetAllCommands()
{
var commands = new List<Command>
{
new Command{Id=0, HowTo="Boil an egg", Line="Boil water", Platform="Kettle & Pan"},
new Command{Id=1, HowTo="Cut bread", Line="Get a knife", Platform="knife & chopping board"},
new Command{Id=2, HowTo="Make cup of tea", Line="Place teabag in cup", Platform="Kettle & cup"}
};
return commands;
}
}
}
新建Dtos文件夹,新建类CommandReadDto.cs
上一步模拟实现了从数据库返回Command实体,但是在返回给前端的时候不能直接返回实体,而是需要转换成Dto。根据不同的业务场景需要建立不同的Dto
namespace Simple_Asp.Net_Core.Dtos
{
public class CommandReadDto
{
public int Id { get; set; }
public string HowTo { get; set; }
public string Line { get; set; }
}
}
实现ICommanderRepo的依赖注入
生命周期是依赖注入里非常重要的内容,具体可以参照官方的文档
https://docs.microsoft.com/en-us/dotnet/core/extensions/dependency-injection#service-lifetimes
这里使用的注册方式是AddScoped,让每一次请求都会创建一个实例
For web applications, a scoped lifetime indicates that services are created once per client request (connection). Register scoped services with AddScoped.
Startup.cs代码调整成如下:
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Newtonsoft.Json.Serialization;
using Simple_Asp.Net_Core.Data;
using Simple_Asp.Net_Core.ServiceProvider;
using System;
namespace Simple_Asp.Net_Core
{
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.AddCORS();
services.AddMvc();
services.AddSwagger();
services.AddScoped<ICommanderRepo, MockCommanderRepo>();
services.AddControllers().AddNewtonsoftJson(s =>
{
s.SerializerSettings.ContractResolver = new CamelCasePropertyNamesContractResolver();
});
}
// 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.UseSwagger();
app.UseSwaggerUI(c =>
{
c.SwaggerEndpoint("/swagger/v1/swagger.json", "ApiHelp V1");
});
}
app.UseCors("CorsTest");
app.UseRouting();
app.UseEndpoints(endpoints => endpoints.MapDefaultControllerRoute());
}
}
}
在编写Restful API之前还差最后一步,AutoMapper的使用
前面已经创建了Command实体与CommandReadDto Dto,现在我们要让这Commond实体能够自动转换成CommandReadDto Dto
AutoMapper引入Nuget包
再一次配置Startup.cs
代码如下:
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Newtonsoft.Json.Serialization;
using Simple_Asp.Net_Core.Data;
using Simple_Asp.Net_Core.ServiceProvider;
using System;
namespace Simple_Asp.Net_Core
{
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.AddCORS();
services.AddMvc();
services.AddSwagger();
services.AddAutoMapper(AppDomain.CurrentDomain.GetAssemblies());
services.AddScoped<ICommanderRepo, MockCommanderRepo>();
services.AddControllers().AddNewtonsoftJson(s =>
{
s.SerializerSettings.ContractResolver = new CamelCasePropertyNamesContractResolver();
});
}
// 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.UseSwagger();
app.UseSwaggerUI(c =>
{
c.SwaggerEndpoint("/swagger/v1/swagger.json", "ApiHelp V1");
});
}
app.UseCors("CorsTest");
app.UseRouting();
app.UseEndpoints(endpoints => endpoints.MapDefaultControllerRoute());
}
}
}
新建Profiles文件夹,新建CommandsProfile.cs AutoMpper映射配置类
代码如下:
using AutoMapper;
using Simple_Asp.Net_Core.Dtos;
using Simple_Asp.Net_Core.Models;
namespace Simple_Asp.Net_Core.Profiles
{
public class CommandsProfile : Profile
{
public CommandsProfile()
{
//Source -> Target
CreateMap<Command, CommandReadDto>();
}
}
}
在Controllers文件夹下新建控制器CommandsController.cs
将接口注入至 CommandsController 构造函数中
这里为了演示直接将仓储层的接口注入至Controller中,实际开发中不能这样处理!
private readonly ICommanderRepo _repository;
private readonly IMapper _mapper;
public CommandsController(ICommanderRepo repository, IMapper mapper)
{
_repository = repository;
_mapper = mapper;
}
这时候我们就可以实现 Commands 中 api/commands 请求
//GET api/commands
[HttpGet]
public ActionResult<IEnumerable<CommandReadDto>> GetAllCommmands()
{
var commandItems = _repository.GetAllCommands();
return Ok(_mapper.Map<IEnumerable<CommandReadDto>>(commandItems));
}
调试项目使用swagger调用api/commands接口,后端能够成功返回数据!
接下来就完成剩下的几种请求
在Dtos文件夹下新建CommandUpdateDto.cs 与 CommandCreateDto.cs
代码如下:
using System.ComponentModel.DataAnnotations;
namespace Simple_Asp.Net_Core.Dtos
{
public class CommandCreateDto
{
[Required]
[MaxLength(250)]
public string HowTo { get; set; }
[Required]
public string Line { get; set; }
[Required]
public string Platform { get; set; }
}
}
using System.ComponentModel.DataAnnotations;
namespace Simple_Asp.Net_Core.Dtos
{
public class CommandUpdateDto
{
[Required]
[MaxLength(250)]
public string HowTo { get; set; }
[Required]
public string Line { get; set; }
[Required]
public string Platform { get; set; }
}
}
修改CommandsProfile.cs
代码如下:
using AutoMapper;
using Simple_Asp.Net_Core.Dtos;
using Simple_Asp.Net_Core.Models;
namespace Simple_Asp.Net_Core.Profiles
{
public class CommandsProfile : Profile
{
public CommandsProfile()
{
//Source -> Target
CreateMap<Command, CommandReadDto>();
CreateMap<CommandCreateDto, Command>();
CreateMap<CommandUpdateDto, Command>();
CreateMap<Command, CommandUpdateDto>();
}
}
}
修改ICommanderRepo.cs
代码如下:
using Simple_Asp.Net_Core.Models;
using System.Collections.Generic;
namespace Simple_Asp.Net_Core.Data
{
public interface ICommanderRepo
{
bool SaveChanges();
IEnumerable<Command> GetAllCommands();
Command GetCommandById(int id);
void CreateCommand(Command cmd);
void UpdateCommand(Command cmd);
void DeleteCommand(Command cmd);
}
}
修改MockCommanderRepo.cs
模拟仓储层我们就不做过多的实现,在下一章内容会与数据库Postgresql进行对接,到时候再实现!
代码如下:
using Simple_Asp.Net_Core.Models;
using System.Collections.Generic;
namespace Simple_Asp.Net_Core.Data
{
public class MockCommanderRepo : ICommanderRepo
{
public void CreateCommand(Command cmd)
{
throw new System.NotImplementedException();
}
public void DeleteCommand(Command cmd)
{
throw new System.NotImplementedException();
}
public IEnumerable<Command> GetAllCommands()
{
var commands = new List<Command>
{
new Command{Id=0, HowTo="Boil an egg", Line="Boil water", Platform="Kettle & Pan"},
new Command{Id=1, HowTo="Cut bread", Line="Get a knife", Platform="knife & chopping board"},
new Command{Id=2, HowTo="Make cup of tea", Line="Place teabag in cup", Platform="Kettle & cup"}
};
return commands;
}
public Command GetCommandById(int id)
{
return new Command { Id = 0, HowTo = "Boil an egg", Line = "Boil water", Platform = "Kettle & Pan" };
}
public bool SaveChanges()
{
throw new System.NotImplementedException();
}
public void UpdateCommand(Command cmd)
{
throw new System.NotImplementedException();
}
}
}
修改CommandsController.cs
代码如下:
using AutoMapper;
using Microsoft.AspNetCore.JsonPatch;
using Microsoft.AspNetCore.Mvc;
using Simple_Asp.Net_Core.Data;
using Simple_Asp.Net_Core.Dtos;
using Simple_Asp.Net_Core.Models;
using System.Collections.Generic;
namespace Simple_Asp.Net_Core.Controllers
{
[Route("api/[controller]")]
[ApiController]
public class CommandsController : ControllerBase
{
private readonly ICommanderRepo _repository;
private readonly IMapper _mapper;
public CommandsController(ICommanderRepo repository, IMapper mapper)
{
_repository = repository;
_mapper = mapper;
}
//GET api/commands
[HttpGet]
public ActionResult<IEnumerable<CommandReadDto>> GetAllCommmands()
{
var commandItems = _repository.GetAllCommands();
return Ok(_mapper.Map<IEnumerable<CommandReadDto>>(commandItems));
}
//GET api/commands/{id}
[HttpGet("{id}", Name = "GetCommandById")]
public ActionResult<CommandReadDto> GetCommandById(int id)
{
var commandItem = _repository.GetCommandById(id);
if (commandItem != null)
{
return Ok(_mapper.Map<CommandReadDto>(commandItem));
}
return NotFound();
}
//POST api/commands
[HttpPost]
public ActionResult<CommandReadDto> CreateCommand(CommandCreateDto commandCreateDto)
{
var commandModel = _mapper.Map<Command>(commandCreateDto);
_repository.CreateCommand(commandModel);
_repository.SaveChanges();
var commandReadDto = _mapper.Map<CommandReadDto>(commandModel);
return CreatedAtRoute(nameof(GetCommandById), new { Id = commandReadDto.Id }, commandReadDto);
}
//PUT api/commands/{id}
[HttpPut("{id}")]
public ActionResult UpdateCommand(int id, CommandUpdateDto commandUpdateDto)
{
var commandModelFromRepo = _repository.GetCommandById(id);
if (commandModelFromRepo == null)
{
return NotFound();
}
_mapper.Map(commandUpdateDto, commandModelFromRepo);
_repository.UpdateCommand(commandModelFromRepo);
_repository.SaveChanges();
return NoContent();
}
//PATCH api/commands/{id}
[HttpPatch("{id}")]
public ActionResult PartialCommandUpdate(int id, JsonPatchDocument<CommandUpdateDto> patchDoc)
{
var commandModelFromRepo = _repository.GetCommandById(id);
if (commandModelFromRepo == null)
{
return NotFound();
}
var commandToPatch = _mapper.Map<CommandUpdateDto>(commandModelFromRepo);
patchDoc.ApplyTo(commandToPatch);
if (!TryValidateModel(commandToPatch))
{
return ValidationProblem(ModelState);
}
_mapper.Map(commandToPatch, commandModelFromRepo);
_repository.UpdateCommand(commandModelFromRepo);
_repository.SaveChanges();
return NoContent();
}
//DELETE api/commands/{id}
[HttpDelete("{id}")]
public ActionResult DeleteCommand(int id)
{
var commandModelFromRepo = _repository.GetCommandById(id);
if (commandModelFromRepo == null)
{
return NotFound();
}
_repository.DeleteCommand(commandModelFromRepo);
_repository.SaveChanges();
return NoContent();
}
}
}
实现HttpPatch的时候需要引入JsonPath Nuget包,可以直接如图所示直接引入,也可以使用Nuget包管理界面进行引入
调试项目,可以看到Restful API 已开发完成!
重点说明 HttpPatch 请求
PUT 和 PATCH 方法用于更新现有资源。 它们之间的区别是,PUT会替换整个资源,而PATCH 仅指定更改。
接来下我们用swagger来验证
参数如下:
[
{
"op":"add",
"path":"/Line",
"value":"Barry"
}
]
调试后端代码,可以看到值已经被我们正确修改了 !
更多Patch语法说明可以参考
https://docs.microsoft.com/zh-cn/aspnet/core/web-api/jsonpatch?view=aspnetcore-5.0
总结
本文主要对Simple项目使用了AutoMapper与依赖注入等内容实现了简单的Restful API开发。在实际开发过程中需要根据不同的业务场景需要建立不同的Dto,不要因为偷懒让相近的业务功能使用相同的Dto,这样会让后续的代码维护成本变得更大!
目前针对AutoMpper的使用并不是非常的便捷,后续可以考虑进行提升。依赖注入使用的是自带的方式实现,后续可以结合第三方组件实现依赖注入
文中提到生命周期是依赖注入里非常重要的内容,在实际开发过程中要根据具体的业务情况使用正确的生命周期!
GitHub源码
注意:源码调试过程中如果出现xml文件路径错误,需要参照第一章(后端项目搭建与Swagger配置步骤)Swagger配置“配置XML 文档文件”步骤,取消勾选然后再选中 ,将XML路径设置成与你的电脑路径匹配!
参考资料
官网文档-依赖注入生命周期(推荐学习) https://docs.microsoft.com/en-us/dotnet/core/extensions/dependency-injection#service-lifetimes
Restful API 案例来源 https://www.youtube.com/watch?v=fmvcAzHpsk8
微软官方文档 https://docs.microsoft.com/zh-cn/aspnet/core/?view=aspnetcore-5.0
DTO理解 https://docs.microsoft.com/en-us/previous-versions/msp-n-p/ff649585(v=pandp.10)?redirectedfrom=MSDN
官网文档-Patch请求详解 https://docs.microsoft.com/zh-cn/aspnet/core/web-api/jsonpatch?view=aspnetcore-5.0
作者:Iannnnnnnnnnnnn
出处:https://www.cnblogs.com/Iannnnnnnnnnnnn
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