ASP.NET Core WebAPI学习-3

不念不忘少年蓝@ 2021-08-24 12:54 260阅读 0赞

1.  [ASP.NET Core WebAPI学习-1][ASP.NET Core WebAPI_-1]
2.  [ASP.NET Core WebAPI学习-2][ASP.NET Core WebAPI_-2]
3.  [ASP.NET Core WebAPI学习-3][ASP.NET Core WebAPI_-3]
4.  [ASP.NET Core WebAPI学习-4][ASP.NET Core WebAPI_-4]
5.  [ASP.NET Core WebAPI学习-5][ASP.NET Core WebAPI_-5]
6.  [ASP.NET Core WebAPI学习-6][ASP.NET Core WebAPI_-6]

## 内容协商(Content Negotiation) AutoMapper的使用 ##

内容协商是这样一个过程：针对一个响应，当有多种表述格式可用的时候，选取最佳的一个表述。数据格式是json,xml等格式  
Media Type(媒体类型)：  
\- applicaion/json  
\- application/xml  
输出格式在Startup.cs中定义,当请求的格式与输出的格式不匹配的时候，会返回406 Not Acceptable状态码  
在ASP.NET Core中Startup的ConfigureServices方法中定义：

services.AddControllers(configure: setup =>
                            {
                                setup.ReturnHttpNotAcceptable = true;
                                //默认格式为json,也支持json
                                setup.OutputFormatters.Add(new XmlDataContractSerializerOutputFormatter());
                                //设置默认的返回格式为xml
                                //setup.OutputFormatters.Insert(index:0,new XmlDataContractSerializerOutputFormatter());
                            });

**在WebAPI中使用ActionResult,可以在swashbuckle时，注释更明确，尽量使用ActionResult**

### 使用AutoMapper ###

1.  安装包：AutoMapper.Extensions.Microsoft.DependencyInjection 7.0.0
2.  在Starup的ConfigureServices方法中中配置服务：

services.AddAutoMapper(AppDomain.CurrentDomain.GetAssemblies());

1.  添加配置文件

using AutoMapper;
    using Routine.Api.Dtos;
    using Routine.Api.Entity;
    
    namespace Routine.Api.Profiles
    {
        public class CompanyProfile : Profile
        {
            public CompanyProfile()
            {
                CreateMap<Company, CompanyDto>()
                    .ForMember(
                        destinationMember: dest => dest.CompanyName,
                        memberOptions: opt => opt.MapFrom(mapExpression: src => src.Name));
    
                CreateMap<CompanyAddDto, Company>();
    
            }
        }
    }

1.  在Controller中的构造函数中注入AutoMappe服务

private readonly ICompanyRepository companyRepository;
    private readonly IMapper mapper;
    public CompaniesController(ICompanyRepository companyRepository, IMapper mapper)
    {
        this.companyRepository = companyRepository ??
            throw new ArgumentNullException(nameof(companyRepository));
        this.mapper = mapper ??
            throw new ArgumentNullException(nameof(mapper));
    }

1.  使用AutoMapper:

var companyDtos = mapper.Map<IEnumerable<CompanyDto>>(companies);

### 自定义错误信息 ###

ASP.NET Core WebAPI内置的api，如果服务端出现运行错误，在Development环境下，会报出详细错误信息，在Production环境下，会返回500状态码，body内无任何信息，可以在Startup.cs的Configure方法中配置：

public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
    {
        if (env.IsDevelopment())
        {
            app.UseDeveloperExceptionPage();
        }
        else
        {
            app.UseExceptionHandler(appBuilder =>
                                    {
                                        appBuilder.Run(handler: async context =>
                                                       {
                                                           context.Response.StatusCode = 500;
                                                           await context.Response.WriteAsync(text: "Unexpected Error!");
                                                       });
                                    });
        }
    
        app.UseRouting();
    
        app.UseAuthorization();
    
        app.UseEndpoints(endpoints =>
                         {
                             endpoints.MapControllers();
                         });
    }

### Http Head ###

header和Get几乎一样，但是不返回body，HEAD可以用来在资源的获取上

[ASP.NET Core WebAPI_-1]: https://blog.csdn.net/xingkongtianyuzhao/article/details/104129685
[ASP.NET Core WebAPI_-2]: https://blog.csdn.net/xingkongtianyuzhao/article/details/104133382
[ASP.NET Core WebAPI_-3]: https://blog.csdn.net/xingkongtianyuzhao/article/details/104133393
[ASP.NET Core WebAPI_-4]: https://blog.csdn.net/xingkongtianyuzhao/article/details/104133416
[ASP.NET Core WebAPI_-5]: https://blog.csdn.net/xingkongtianyuzhao/article/details/104133486
[ASP.NET Core WebAPI_-6]: https://blog.csdn.net/xingkongtianyuzhao/article/details/104133573