NetCore+Dapper WebApi架构搭建（四）：仓储的依赖注入

上一节我们讲到实体，仓储接口和仓储接口的实现需要遵循约定的命名规范，不仅是规范，而且为了依赖注入，现在我们实现仓储的依赖注入

在NetCore WebApi项目中新添加一个文件夹（Unit），当然你也可以直接放在根目录下面，关键是后期类增加了你会找对地方，看起来不是那么乱，添加一个RuntimeHelper

我先说一下实现仓储依赖注入的基本思路，就是通过反射获取所有的程序集，然后在程序集中找到 I+实体+Repository的接口和 实体+Repository的实现类，然后在依赖注入容器中注册他们的对应关系

所以这个RuntimeHelper很明显是通过反射获取程序集使用的

using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.DependencyModel;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Runtime.Loader;

namespace Dinner.WebApi.Unit
{
    [ApiExplorerSettings(IgnoreApi=true)]
    public class RuntimeHelper
    {
        /// <summary>
        /// 获取项目程序集，排除所有的系统程序集(Microsoft.***、System.***等)、Nuget下载包
        /// </summary>
        /// <returns></returns>
        public static IList<Assembly> GetAllAssemblies()
        {
            List<Assembly> list = new List<Assembly>();
            var deps = DependencyContext.Default;
            //排除所有的系统程序集、Nuget下载包
            var libs = deps.CompileLibraries.Where(lib => !lib.Serviceable && lib.Type != "package");
            foreach (var lib in libs)
            {
                try
                {
                    var assembly = AssemblyLoadContext.Default.LoadFromAssemblyName(new AssemblyName(lib.Name));
                    list.Add(assembly);
                }
                catch (Exception ex)
                {
                    //
                }
            }
            return list;
        }

        public static Assembly GetAssembly(string assemblyName)
        {
            return GetAllAssemblies().FirstOrDefault(f => f.FullName.Contains(assemblyName));
        }

        public static IList<Type> GetAllTypes()
        {
            List<Type> list = new List<Type>();
            foreach (var assembly in GetAllAssemblies())
            {
                var typeinfos = assembly.DefinedTypes;
                foreach (var typeinfo in typeinfos)
                {
                    list.Add(typeinfo.AsType());
                }
            }
            return list;
        }

        /// <summary>
        /// 根据AssemblyName获取所有的类
        /// </summary>
        /// <param name="assemblyName"></param>
        /// <returns></returns>
        public static IList<Type> GetTypesByAssembly(string assemblyName)
        {
            List<Type> list = new List<Type>();
            var assembly = AssemblyLoadContext.Default.LoadFromAssemblyName(new AssemblyName(assemblyName));
            var typeinfos = assembly.DefinedTypes;
            foreach (var typeinfo in typeinfos)
            {
                list.Add(typeinfo.AsType());
            }
            return list;
        }

        public static Type GetImplementType(string typeName, Type baseInterfaceType)
        {
            return GetAllTypes().FirstOrDefault(t =>
            {
                if (t.Name == typeName && t.GetTypeInfo().GetInterfaces().Any(b => b.Name == baseInterfaceType.Name))
                {
                    var typeinfo = t.GetTypeInfo();
                    return typeinfo.IsClass && !typeinfo.IsAbstract && !typeinfo.IsGenericType;
                }
                return false;
            });
        }
    }
}

上面的那个[ApiExplorerSettings(IgnoreApi=true)]是使用Swagger时使用的，这个我们后面会讲

上面的类就是是反射对程序集的操作

这个我们要使用第三方的Autofac依赖注入框架，所以先引入Nuget包：Autofac.Configuration和Autofac.Extensions.DependencyInjection

下面打开startUp.cs类

先把ConfigureServices方法的返回值由void变为IServiceProvider

然后在ConfigureServices的AddMvc()之后添加下面代码

#region 依赖注入

            var builder = new ContainerBuilder();//实例化容器
            //注册所有模块module
            builder.RegisterAssemblyModules(Assembly.GetExecutingAssembly());
            //获取所有的程序集
            //var assemblys = BuildManager.GetReferencedAssemblies().Cast<Assembly>().ToArray();
            var assemblys = RuntimeHelper.GetAllAssemblies().ToArray();

            //注册所有继承IDependency接口的类
            builder.RegisterAssemblyTypes().Where(type => typeof(IDependency).IsAssignableFrom(type) && !type.IsAbstract);
            //注册仓储，所有IRepository接口到Repository的映射
            builder.RegisterAssemblyTypes(assemblys).Where(t => t.Name.EndsWith("Repository") && !t.Name.StartsWith("I")).AsImplementedInterfaces();
            //注册服务，所有IApplicationService到ApplicationService的映射
            //builder.RegisterAssemblyTypes(assemblys).Where(t => t.Name.EndsWith("AppService") && !t.Name.StartsWith("I")).AsImplementedInterfaces();
            builder.Populate(services);
            ApplicationContainer = builder.Build();

            return new AutofacServiceProvider(ApplicationContainer); //第三方IOC接管 core内置DI容器 
            //return services.BuilderInterceptableServiceProvider(builder => builder.SetDynamicProxyFactory());
            #endregion

这样以来注入就可以了

现在添加一个UsersController进行测试

using Dinner.Dapper.Entities;
using Dinner.Dapper.IRepository;
using Microsoft.AspNetCore.Mvc;
using System;
using System.Collections.Generic;
using System.Threading.Tasks;

namespace Dinner.WebApi.Controllers
{

    [Route("api/[controller]/[action]")]
    public class UsersController : Controller
    {
        private readonly IUserRepository userRepository;
        public UsersController(IUserRepository _userRepository)
        {
            userRepository = _userRepository;
        }

        /// <summary>
        /// 获取所有用户
        /// </summary>
        /// <returns></returns>
        /// 
        [HttpGet]
        public async Task<JsonResult> GetUsers()
        {
            List<Users> list = await userRepository.GetUsers();
            return Json(list);
        }

        /// <summary>
        /// 新增用户
        /// </summary>
        /// <param name="entity"></param>
        /// <returns></returns>
        [HttpPost]
        public async Task PostUser(Users entity)
        {
            entity.Password = Dapper.Helpers.Encrypt.Md5(entity.Password).ToUpper();
            await userRepository.PostUser(entity);
        }

        /// <summary>
        /// 修改用户信息
        /// </summary>
        /// <param name="entity"></param>
        /// <returns></returns>
        [HttpPut]
        public async Task PutUser(Users entity)
        {
            try
            {
                entity.Password = Dapper.Helpers.Encrypt.Md5(entity.Password).ToUpper();
                await userRepository.PutUser(entity);
            }
            catch (Exception ex)
            {
                throw new ArgumentException(ex.Message);
            }
        }

        /// <summary>
        /// 删除用户
        /// </summary>
        /// <param name="Id"></param>
        /// <returns></returns>
        [HttpDelete]
        public async Task DeleteUser(Guid Id)
        {
            try
            {
                await userRepository.DeleteUser(Id);
            }
            catch (Exception ex)
            {
                throw new ArgumentException(ex.Message);
            }
        }
    }
}

自己测试一下仓储的增删改查吧，看看写的有问题没有

下一节我们讲解Swagger构建WebApi界面

赠送一个Framework版本的依赖注入

#region autofac IOC容器配置
            var builder = new ContainerBuilder();

            //注册所有的controller
            builder.RegisterControllers(typeof(MvcApplication).Assembly).PropertiesAutowired();
            //注册所有模块module
            builder.RegisterAssemblyModules(Assembly.GetExecutingAssembly());

            var assemblys = BuildManager.GetReferencedAssemblies().Cast<Assembly>().ToArray();

            //注册所有继承IDependency接口的类
            builder.RegisterAssemblyTypes(assemblys)
            .Where(type => typeof(IDependency).IsAssignableFrom(type) && !type.IsAbstract);

            //注册服务，所有IxxxxRepository=>xxxxRepository
            builder.RegisterAssemblyTypes(assemblys).Where(t => t.Name.EndsWith("Repository") && !t.Name.StartsWith("I")).AsImplementedInterfaces();
          
            var container = builder.Build();

            BaseInfo._container = container;

            DependencyResolver.SetResolver(new AutofacDependencyResolver(container));
            #endregion

源码地址： https://github.com/wangyulong0505/Dinner