.net core3.0 使用Autofac实现自动注入

大多时候我们采用一下方式进行依赖注入

 随着业务的增长，接口跟实现类会越来越多，还需要手动一个个的注册依赖项，有时候会出现忘了写配置，导致程序报错，如果是多人开发，可能还会导致代码冲突，后期维护起来相对来说比较麻烦。

使用Autofac自动注入

1、安装Autofac.Extensions.DependencyInjection

2、修改Program.cs

 public static IHostBuilder CreateHostBuilder(string[] args) =>
            Host.CreateDefaultBuilder(args)
                .ConfigureWebHostDefaults(webBuilder =>
                {
                    webBuilder.UseStartup<Startup>();
                })
               .UseServiceProviderFactory(new AutofacServiceProviderFactory());

3、在Startup.cs中添加ConfigureContainer方法

 public void ConfigureContainer(ContainerBuilder builder)
        {
            builder.RegisterAssemblyTypes(typeof(Program).Assembly)
                    .Where(x => x.Name.EndsWith("service", StringComparison.OrdinalIgnoreCase)).AsImplementedInterfaces();
        }

接口层以I开头Service层都要以Service为结尾。

测试：

 public interface IArticleService
    {
        IEnumerable<Article> QueryArticle();

        int SaveArticle(Article article);

        Article GetArticleById(int Id);

        Page<Article> GetArticlePage(int page, int size, string searchval);

        int DelArticle(int Id);
    }

 public class ArticleService : BaseService, IArticleService
    {
        /// <summary>
        /// 查询文章
        /// </summary>
        /// <returns></returns>
        public Article GetArticleById(int Id)
        {
            var sql = Sql.Builder.Append("SELECT * FROM MST_ARTICLE WHERE Id=@id", new
            {
                id = Id
            });
            return database.SingleOrDefault<Article>(sql);
        }
}

在控制器中注入IArticleService

 [ApiController]
    [Route("api/[controller]/[action]")]
    public class ArticleController : Controller
    {
        private IArticleService _articleService;

        private readonly IMapper _mapper;

        public ArticleController(IArticleService articleService, IMapper mapper)
        {
            _articleService = articleService;
            _mapper = mapper;
        }