ASP.NET Core Web 应用程序系列(三)- 在ASP.NET Core中使用Autofac替换自带DI进行构造函数和属性的批量依赖注入(MVC当中应用)

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在上一章中主要和大家分享了在ASP.NET Core中如何使用Autofac替换自带DI进行构造函数的批量依赖注入,本章将和大家继续分享如何使之能够同时支持属性的批量依赖注入。

约定:

1、仓储层接口都以“I”开头,以“Repository”结尾。仓储层实现都以“Repository”结尾。

2、服务层接口都以“I”开头,以“Service”结尾。服务层实现都以“Service”结尾。

接下来我们正式进入主题,在上一章的基础上我们再添加一个web项目TianYa.DotNetShare.CoreAutofacDemo,首先来看一下我们的解决方案

本demo的web项目为ASP.NET Core Web 应用程序(.NET Core 2.2) MVC框架,需要引用以下几个程序集:

1、TianYa.DotNetShare.Model 我们的实体层

2、TianYa.DotNetShare.Service 我们的服务层

3、TianYa.DotNetShare.Repository 我们的仓储层,正常我们的web项目是不应该使用仓储层的,此处我们引用是为了演示IOC依赖注入

4、Autofac 依赖注入基础组件

5、Autofac.Extensions.DependencyInjection 依赖注入.NET Core的辅助组件

其中Autofac和Autofac.Extensions.DependencyInjection需要从我们的NuGet上引用,依次点击下载以下2个包:

接着我们在web项目中添加一个类AutofacModuleRegister.cs用来注册Autofac模块,如下所示:

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

using Autofac;

namespace TianYa.DotNetShare.CoreAutofacDemo
{
    /// <summary>
    /// 注册Autofac模块
    /// </summary>
    public class AutofacModuleRegister : Autofac.Module
    {
        /// <summary>
        /// 重写Autofac管道Load方法,在这里注册注入
        /// </summary>
        protected override void Load(ContainerBuilder builder)
        {
            //builder.RegisterType<StudentRepository>().As<IStudentRepository>().PropertiesAutowired()
            //    .InstancePerLifetimeScope();
            //builder.RegisterType<StudentService>().As<IStudentService>().PropertiesAutowired()
            //    .InstancePerLifetimeScope();

            builder.RegisterAssemblyTypes(GetAssemblyByName("TianYa.DotNetShare.Repository"))
                .Where(a => a.Name.EndsWith("Repository"))
                .AsSelf().AsImplementedInterfaces().PropertiesAutowired().InstancePerLifetimeScope();

            builder.RegisterAssemblyTypes(GetAssemblyByName("TianYa.DotNetShare.Service"))
                .Where(a => a.Name.EndsWith("Service"))
                .AsSelf().AsImplementedInterfaces().PropertiesAutowired().InstancePerLifetimeScope();

            //注册MVC控制器,注册所有到控制器
            var controllersTypesInAssembly = typeof(Startup).Assembly.GetExportedTypes()
                .Where(type => typeof(Microsoft.AspNetCore.Mvc.ControllerBase).IsAssignableFrom(type)).ToArray();
            builder.RegisterTypes(controllersTypesInAssembly).PropertiesAutowired();
        }

        /// <summary>
        /// 根据程序集名称获取程序集
        /// </summary>
        /// <param name="assemblyName">程序集名称</param>
        public static Assembly GetAssemblyByName(string assemblyName)
        {
            return Assembly.Load(assemblyName);
        }
    }
}

然后打开我们的Startup.cs文件进行注入工作,如下所示:

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.AspNetCore.Mvc;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;

using Autofac;
using Autofac.Extensions.DependencyInjection;

namespace TianYa.DotNetShare.CoreAutofacDemo
{
    public class Startup
    {
        public Startup(IConfiguration configuration)
        {
            Configuration = configuration;
        }

        public IConfiguration Configuration { get; }

        // This method gets called by the runtime. Use this method to add services to the container.
        public IServiceProvider ConfigureServices(IServiceCollection services)
        {
            services.Configure<CookiePolicyOptions>(options =>
            {
                // This lambda determines whether user consent for non-essential cookies is needed for a given request.
                options.CheckConsentNeeded = context => true;
                options.MinimumSameSitePolicy = SameSiteMode.None;
            });

            services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_2).AddControllersAsServices();

            return RegisterAutofac(services); //注册Autofac
        }

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

            app.UseStaticFiles();
            app.UseCookiePolicy();

            app.UseMvc(routes =>
            {
                routes.MapRoute(
                    name: "default",
                    template: "{controller=Home}/{action=Index}/{id?}");
            });
        }

        /// <summary>
        /// 注册Autofac
        /// </summary>
        private IServiceProvider RegisterAutofac(IServiceCollection services)
        {
            //实例化Autofac容器
            var builder = new ContainerBuilder();
            //将services中的服务填充到Autofac中
            builder.Populate(services);
            //新模块组件注册    
            builder.RegisterModule<AutofacModuleRegister>();
            //创建容器
            var container = builder.Build();
            //第三方IoC容器接管Core内置DI容器 
            return new AutofacServiceProvider(container);
        }
    }
}

PS:

1、需要将自带的ConfigureServices方法的返回值改成IServiceProvider。

2、需要修改如下语句:

将原有的:

services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_2);

改为:

services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_2).AddControllersAsServices();

接下来我们来看看控制器里面怎么弄:

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc;
using TianYa.DotNetShare.CoreAutofacDemo.Models;

using TianYa.DotNetShare.Service;
using TianYa.DotNetShare.Repository;
using TianYa.DotNetShare.Repository.Impl;

namespace TianYa.DotNetShare.CoreAutofacDemo.Controllers
{
    public class HomeController : Controller
    {
        /// <summary>
        /// 定义仓储层学生抽象类对象
        /// </summary>
        private IStudentRepository _stuRepository;

        /// <summary>
        /// 定义服务层学生抽象类对象
        /// </summary>
        private IStudentService _stuService;

        /// <summary>
        /// 定义服务层学生抽象类对象
        /// 属性注入:访问修饰符必须为public,否则会注入失败。
        /// </summary>
        public IStudentService StuService { get; set; }

        /// <summary>
        /// 定义仓储层学生实现类对象
        /// 属性注入:访问修饰符必须为public,否则会注入失败。
        /// </summary>
        public StudentRepository StuRepository { get; set; }

        /// <summary>
        /// 通过构造函数进行注入
        /// 注意:参数是抽象类,而非实现类,因为已经在Startup.cs中将实现类映射给了抽象类
        /// </summary>
        /// <param name="stuRepository">仓储层学生抽象类对象</param>
        /// <param name="stuService">服务层学生抽象类对象</param>
        public HomeController(IStudentRepository stuRepository, IStudentService stuService)
        {
            this._stuRepository = stuRepository;
            this._stuService = stuService;
        }

        public IActionResult Index()
        {
            var stu1 = StuRepository.GetStuInfo("10000");
            var stu2 = StuService.GetStuInfo("10001");
            var stu3 = _stuService.GetStuInfo("10002");
            var stu4 = _stuRepository.GetStuInfo("1003");
            string msg = $"学号:10000,姓名:{stu1.Name},性别:{stu1.Sex},年龄:{stu1.Age}<br />";
            msg += $"学号:10001,姓名:{stu2.Name},性别:{stu2.Sex},年龄:{stu2.Age}<br/>";
            msg += $"学号:10002,姓名:{stu3.Name},性别:{stu3.Sex},年龄:{stu3.Age}<br/>";
            msg += $"学号:10003,姓名:{stu4.Name},性别:{stu4.Sex},年龄:{stu4.Age}<br/>";

            return Content(msg, "text/html", System.Text.Encoding.UTF8);
        }

        public IActionResult Privacy()
        {
            return View();
        }

        [ResponseCache(Duration = 0, Location = ResponseCacheLocation.None, NoStore = true)]
        public IActionResult Error()
        {
            return View(new ErrorViewModel { RequestId = Activity.Current?.Id ?? HttpContext.TraceIdentifier });
        }
    }
}

至此完成处理,接下来就是见证奇迹的时刻了,我们来访问一下/home/index,看看是否能返回学生信息。

可以发现,返回了学生的信息,说明我们注入成功了。

至此,本章就介绍完了,如果你觉得这篇文章对你有所帮助请记得点赞哦,谢谢!!!

demo源码:

链接:https://pan.baidu.com/s/11RM9jUr9n342TmV8z8MEHA 
提取码:86s0

版权声明:如有雷同纯属巧合,如有侵权请及时联系本人修改,谢谢!!!

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