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