我的NopCommerce之旅(7): 依赖注入(IOC/DI)
一、基础介绍
依赖注入，Dependency Injection，权威解释及说明请自己查阅资料。
这里简单说一下常见使用：在mvc的controller的构造方法中定义参数，如ICountryService countryService，然后直接使用countryService(构造注入)。
public CountryController(ICountryService countryService,
IStateProvinceService stateProvinceService,
ILocalizationService localizationService,
IWorkContext workContext,
ICacheManager cacheManager)
{
this._countryService = countryService;
this._stateProvinceService = stateProvinceService;
this._localizationService = localizationService;
this._workContext = workContext;
this._cacheManager = cacheManager;
}
显然，你并没有在controller调用前，new一个ICountryService的对象给controller做参数，你也不知道该在哪去写这个调用。没关系，这些都交给系统处理，你不必理会，这就是依赖注入。
二、承上启下
上一篇大致分析了应用启动，而NopCommerce完成注册依赖就在初始化上下文部分。通过代码跟踪，即可发现Nop.Core.Infrastructure.NopEngine.RegisterDependencies()。
//initialize engine context 初始化上下文
EngineContext.Initialize(false);
/// <summary>
/// Initializes a static instance of the Nop factory.
/// </summary>
/// <param name="forceRecreate">Creates a new factory instance even though the factory has been previously initialized.</param>
[MethodImpl(MethodImplOptions.Synchronized)]
public static IEngine Initialize(bool forceRecreate)
{
if (Singleton<IEngine>.Instance == null || forceRecreate)
{
Singleton<IEngine>.Instance = new NopEngine(); var config = ConfigurationManager.GetSection("NopConfig") as NopConfig;
Singleton<IEngine>.Instance.Initialize(config);
}
return Singleton<IEngine>.Instance;
}
/// <summary>
/// Initialize components and plugins in the nop environment.
/// </summary>
/// <param name="config">Config</param>
public void Initialize(NopConfig config)
{
//register dependencies
RegisterDependencies(config); //startup tasks
if (!config.IgnoreStartupTasks)
{
RunStartupTasks();
} }
/// <summary>
/// Register dependencies
/// </summary>
/// <param name="config">Config</param>
protected virtual void RegisterDependencies(NopConfig config)
{
var builder = new ContainerBuilder();
var container = builder.Build();
this._containerManager = new ContainerManager(container); //we create new instance of ContainerBuilder
//because Build() or Update() method can only be called once on a ContainerBuilder. //dependencies
var typeFinder = new WebAppTypeFinder();
builder = new ContainerBuilder();
builder.RegisterInstance(config).As<NopConfig>().SingleInstance();
builder.RegisterInstance(this).As<IEngine>().SingleInstance();
builder.RegisterInstance(typeFinder).As<ITypeFinder>().SingleInstance();
builder.Update(container); //register dependencies provided by other assemblies
builder = new ContainerBuilder();
var drTypes = typeFinder.FindClassesOfType<IDependencyRegistrar>();
var drInstances = new List<IDependencyRegistrar>();
foreach (var drType in drTypes)
drInstances.Add((IDependencyRegistrar) Activator.CreateInstance(drType));
//sort
drInstances = drInstances.AsQueryable().OrderBy(t => t.Order).ToList();
foreach (var dependencyRegistrar in drInstances)
dependencyRegistrar.Register(builder, typeFinder, config);通过反射，按顺序注册依赖
builder.Update(container); //set dependency resolver
DependencyResolver.SetResolver(new AutofacDependencyResolver(container));
}
三、NopCommerce的结构分析
本文通过从依赖注入框架Autofac的DependencyRegistrar方法来分析NopCommerce的结构。
1.分析方法
在vs里Solution Explorer的查找栏输入DependencyRegistrar，即可看到所有实现DependencyRegistrar()方法的。
2.总结
2.1 Nop.Core定义了接口；
2.2 Plugins注册自己需要的类；
2.3 Nop.Admin和Nop.Web注册Controller所要使用的缓存类；
2.4 Nop.Web.Framework注册了NopCommerce的核心类。
四、代码分析
1.这里主要分析Nop.Web.Framework的DependencyRegistrar()
1.1.注册http上下文；
1.2.注册web helper、user agent helper；
1.3.注册mvc的controllers；
1.4.注册数据层类，如dbcontext，manager，repository，供持久化层的操作；
1.5.注册插件plugins；
1.6.注册缓存管理的相关类；
1.7.注册work context和store context；
1.8.注册业务层services，部分需注册缓存参数，可以看到WithParameter( ResolvedParameter.ForNamed< ICacheManager >("nop_cache_static" ))；
1.9.注册用户事件。
2.代码如下
/// <summary>
/// Register services and interfaces
/// </summary>
/// <param name="builder">Container builder</param>
/// <param name="typeFinder">Type finder</param>
/// <param name="config">Config</param>
public virtual void Register(ContainerBuilder builder, ITypeFinder typeFinder, NopConfig config)
{
//HTTP context and other related stuff
builder.Register(c =>
//register FakeHttpContext when HttpContext is not available
HttpContext.Current != null ?
(new HttpContextWrapper(HttpContext.Current) as HttpContextBase) :
(new FakeHttpContext("~/") as HttpContextBase))
.As<HttpContextBase>()
.InstancePerLifetimeScope();
builder.Register(c => c.Resolve<HttpContextBase>().Request)
.As<HttpRequestBase>()
.InstancePerLifetimeScope();
builder.Register(c => c.Resolve<HttpContextBase>().Response)
.As<HttpResponseBase>()
.InstancePerLifetimeScope();
builder.Register(c => c.Resolve<HttpContextBase>().Server)
.As<HttpServerUtilityBase>()
.InstancePerLifetimeScope();
builder.Register(c => c.Resolve<HttpContextBase>().Session)
.As<HttpSessionStateBase>()
.InstancePerLifetimeScope(); //web helper
builder.RegisterType<WebHelper>().As<IWebHelper>().InstancePerLifetimeScope();
//user agent helper
builder.RegisterType<UserAgentHelper>().As<IUserAgentHelper>().InstancePerLifetimeScope(); //controllers
builder.RegisterControllers(typeFinder.GetAssemblies().ToArray()); //data layer
var dataSettingsManager = new DataSettingsManager();
var dataProviderSettings = dataSettingsManager.LoadSettings();
builder.Register(c => dataSettingsManager.LoadSettings()).As<DataSettings>();
builder.Register(x => new EfDataProviderManager(x.Resolve<DataSettings>())).As<BaseDataProviderManager>().InstancePerDependency(); builder.Register(x => x.Resolve<BaseDataProviderManager>().LoadDataProvider()).As<IDataProvider>().InstancePerDependency(); if (dataProviderSettings != null && dataProviderSettings.IsValid())
{
var efDataProviderManager = new EfDataProviderManager(dataSettingsManager.LoadSettings());
var dataProvider = efDataProviderManager.LoadDataProvider();
dataProvider.InitConnectionFactory(); builder.Register<IDbContext>(c => new NopObjectContext(dataProviderSettings.DataConnectionString)).InstancePerLifetimeScope();
}
else
{
builder.Register<IDbContext>(c => new NopObjectContext(dataSettingsManager.LoadSettings().DataConnectionString)).InstancePerLifetimeScope();
} builder.RegisterGeneric(typeof(EfRepository<>)).As(typeof(IRepository<>)).InstancePerLifetimeScope(); //plugins
builder.RegisterType<PluginFinder>().As<IPluginFinder>().InstancePerLifetimeScope();
builder.RegisterType<OfficialFeedManager>().As<IOfficialFeedManager>().InstancePerLifetimeScope(); //cache managers
if (config.RedisCachingEnabled)
{
builder.RegisterType<RedisCacheManager>().As<ICacheManager>().Named<ICacheManager>("nop_cache_static").InstancePerLifetimeScope();
}
else
{
builder.RegisterType<MemoryCacheManager>().As<ICacheManager>().Named<ICacheManager>("nop_cache_static").SingleInstance();
}
builder.RegisterType<PerRequestCacheManager>().As<ICacheManager>().Named<ICacheManager>("nop_cache_per_request").InstancePerLifetimeScope(); if (config.RunOnAzureWebsites)
{
builder.RegisterType<AzureWebsitesMachineNameProvider>().As<IMachineNameProvider>().SingleInstance();
}
else
{
builder.RegisterType<DefaultMachineNameProvider>().As<IMachineNameProvider>().SingleInstance();
} //work context
builder.RegisterType<WebWorkContext>().As<IWorkContext>().InstancePerLifetimeScope();
//store context
builder.RegisterType<WebStoreContext>().As<IStoreContext>().InstancePerLifetimeScope(); //services
builder.RegisterType<BackInStockSubscriptionService>().As<IBackInStockSubscriptionService>().InstancePerLifetimeScope();
builder.RegisterType<CategoryService>().As<ICategoryService>().InstancePerLifetimeScope();
builder.RegisterType<CompareProductsService>().As<ICompareProductsService>().InstancePerLifetimeScope();
builder.RegisterType<RecentlyViewedProductsService>().As<IRecentlyViewedProductsService>().InstancePerLifetimeScope();
builder.RegisterType<ManufacturerService>().As<IManufacturerService>().InstancePerLifetimeScope();
builder.RegisterType<PriceFormatter>().As<IPriceFormatter>().InstancePerLifetimeScope();
builder.RegisterType<ProductAttributeFormatter>().As<IProductAttributeFormatter>().InstancePerLifetimeScope();
builder.RegisterType<ProductAttributeParser>().As<IProductAttributeParser>().InstancePerLifetimeScope();
builder.RegisterType<ProductAttributeService>().As<IProductAttributeService>().InstancePerLifetimeScope();
builder.RegisterType<ProductService>().As<IProductService>().InstancePerLifetimeScope();
builder.RegisterType<CopyProductService>().As<ICopyProductService>().InstancePerLifetimeScope();
builder.RegisterType<SpecificationAttributeService>().As<ISpecificationAttributeService>().InstancePerLifetimeScope();
builder.RegisterType<ProductTemplateService>().As<IProductTemplateService>().InstancePerLifetimeScope();
builder.RegisterType<CategoryTemplateService>().As<ICategoryTemplateService>().InstancePerLifetimeScope();
builder.RegisterType<ManufacturerTemplateService>().As<IManufacturerTemplateService>().InstancePerLifetimeScope();
builder.RegisterType<TopicTemplateService>().As<ITopicTemplateService>().InstancePerLifetimeScope();
//use static cache (between HTTP requests)
builder.RegisterType<ProductTagService>().As<IProductTagService>()
.WithParameter(ResolvedParameter.ForNamed<ICacheManager>("nop_cache_static"))
.InstancePerLifetimeScope(); builder.RegisterType<AddressAttributeFormatter>().As<IAddressAttributeFormatter>().InstancePerLifetimeScope();
builder.RegisterType<AddressAttributeParser>().As<IAddressAttributeParser>().InstancePerLifetimeScope();
builder.RegisterType<AddressAttributeService>().As<IAddressAttributeService>().InstancePerLifetimeScope();
builder.RegisterType<AddressService>().As<IAddressService>().InstancePerLifetimeScope();
builder.RegisterType<AffiliateService>().As<IAffiliateService>().InstancePerLifetimeScope();
builder.RegisterType<VendorService>().As<IVendorService>().InstancePerLifetimeScope();
builder.RegisterType<SearchTermService>().As<ISearchTermService>().InstancePerLifetimeScope();
builder.RegisterType<GenericAttributeService>().As<IGenericAttributeService>().InstancePerLifetimeScope();
builder.RegisterType<FulltextService>().As<IFulltextService>().InstancePerLifetimeScope();
builder.RegisterType<MaintenanceService>().As<IMaintenanceService>().InstancePerLifetimeScope(); builder.RegisterType<CustomerAttributeParser>().As<ICustomerAttributeParser>().InstancePerLifetimeScope();
builder.RegisterType<CustomerAttributeService>().As<ICustomerAttributeService>().InstancePerLifetimeScope();
builder.RegisterType<CustomerService>().As<ICustomerService>().InstancePerLifetimeScope();
builder.RegisterType<CustomerRegistrationService>().As<ICustomerRegistrationService>().InstancePerLifetimeScope();
builder.RegisterType<CustomerReportService>().As<ICustomerReportService>().InstancePerLifetimeScope(); //use static cache (between HTTP requests)
builder.RegisterType<PermissionService>().As<IPermissionService>()
.WithParameter(ResolvedParameter.ForNamed<ICacheManager>("nop_cache_static"))
.InstancePerLifetimeScope();
//use static cache (between HTTP requests)
builder.RegisterType<AclService>().As<IAclService>()
.WithParameter(ResolvedParameter.ForNamed<ICacheManager>("nop_cache_static"))
.InstancePerLifetimeScope();
//use static cache (between HTTP requests)
builder.RegisterType<PriceCalculationService>().As<IPriceCalculationService>()
.WithParameter(ResolvedParameter.ForNamed<ICacheManager>("nop_cache_static"))
.InstancePerLifetimeScope(); builder.RegisterType<GeoLookupService>().As<IGeoLookupService>().InstancePerLifetimeScope();
builder.RegisterType<CountryService>().As<ICountryService>().InstancePerLifetimeScope();
builder.RegisterType<CurrencyService>().As<ICurrencyService>().InstancePerLifetimeScope();
builder.RegisterType<MeasureService>().As<IMeasureService>().InstancePerLifetimeScope();
builder.RegisterType<StateProvinceService>().As<IStateProvinceService>().InstancePerLifetimeScope(); builder.RegisterType<StoreService>().As<IStoreService>().InstancePerLifetimeScope();
//use static cache (between HTTP requests)
builder.RegisterType<StoreMappingService>().As<IStoreMappingService>()
.WithParameter(ResolvedParameter.ForNamed<ICacheManager>("nop_cache_static"))
.InstancePerLifetimeScope(); builder.RegisterType<DiscountService>().As<IDiscountService>().InstancePerLifetimeScope(); //use static cache (between HTTP requests)
builder.RegisterType<SettingService>().As<ISettingService>()
.WithParameter(ResolvedParameter.ForNamed<ICacheManager>("nop_cache_static"))
.InstancePerLifetimeScope();
builder.RegisterSource(new SettingsSource()); //use static cache (between HTTP requests)
builder.RegisterType<LocalizationService>().As<ILocalizationService>()
.WithParameter(ResolvedParameter.ForNamed<ICacheManager>("nop_cache_static"))
.InstancePerLifetimeScope(); //use static cache (between HTTP requests)
builder.RegisterType<LocalizedEntityService>().As<ILocalizedEntityService>()
.WithParameter(ResolvedParameter.ForNamed<ICacheManager>("nop_cache_static"))
.InstancePerLifetimeScope();
builder.RegisterType<LanguageService>().As<ILanguageService>().InstancePerLifetimeScope(); builder.RegisterType<DownloadService>().As<IDownloadService>().InstancePerLifetimeScope();
//picture service
var useAzureBlobStorage = !String.IsNullOrEmpty(config.AzureBlobStorageConnectionString);
if (useAzureBlobStorage)
{
//Windows Azure BLOB
builder.RegisterType<AzurePictureService>().As<IPictureService>().InstancePerLifetimeScope();
}
else
{
//standard file system
builder.RegisterType<PictureService>().As<IPictureService>().InstancePerLifetimeScope();
} builder.RegisterType<MessageTemplateService>().As<IMessageTemplateService>().InstancePerLifetimeScope();
builder.RegisterType<QueuedEmailService>().As<IQueuedEmailService>().InstancePerLifetimeScope();
builder.RegisterType<NewsLetterSubscriptionService>().As<INewsLetterSubscriptionService>().InstancePerLifetimeScope();
builder.RegisterType<CampaignService>().As<ICampaignService>().InstancePerLifetimeScope();
builder.RegisterType<EmailAccountService>().As<IEmailAccountService>().InstancePerLifetimeScope();
builder.RegisterType<WorkflowMessageService>().As<IWorkflowMessageService>().InstancePerLifetimeScope();
builder.RegisterType<MessageTokenProvider>().As<IMessageTokenProvider>().InstancePerLifetimeScope();
builder.RegisterType<Tokenizer>().As<ITokenizer>().InstancePerLifetimeScope();
builder.RegisterType<EmailSender>().As<IEmailSender>().InstancePerLifetimeScope(); builder.RegisterType<CheckoutAttributeFormatter>().As<ICheckoutAttributeFormatter>().InstancePerLifetimeScope();
builder.RegisterType<CheckoutAttributeParser>().As<ICheckoutAttributeParser>().InstancePerLifetimeScope();
builder.RegisterType<CheckoutAttributeService>().As<ICheckoutAttributeService>().InstancePerLifetimeScope();
builder.RegisterType<GiftCardService>().As<IGiftCardService>().InstancePerLifetimeScope();
builder.RegisterType<OrderService>().As<IOrderService>().InstancePerLifetimeScope();
builder.RegisterType<OrderReportService>().As<IOrderReportService>().InstancePerLifetimeScope();
builder.RegisterType<OrderProcessingService>().As<IOrderProcessingService>().InstancePerLifetimeScope();
builder.RegisterType<OrderTotalCalculationService>().As<IOrderTotalCalculationService>().InstancePerLifetimeScope();
builder.RegisterType<ReturnRequestService>().As<IReturnRequestService>().InstancePerLifetimeScope();
builder.RegisterType<RewardPointService>().As<IRewardPointService>().InstancePerLifetimeScope();
builder.RegisterType<ShoppingCartService>().As<IShoppingCartService>().InstancePerLifetimeScope(); builder.RegisterType<PaymentService>().As<IPaymentService>().InstancePerLifetimeScope(); builder.RegisterType<EncryptionService>().As<IEncryptionService>().InstancePerLifetimeScope();
builder.RegisterType<FormsAuthenticationService>().As<IAuthenticationService>().InstancePerLifetimeScope(); //use static cache (between HTTP requests)
builder.RegisterType<UrlRecordService>().As<IUrlRecordService>()
.WithParameter(ResolvedParameter.ForNamed<ICacheManager>("nop_cache_static"))
.InstancePerLifetimeScope(); builder.RegisterType<ShipmentService>().As<IShipmentService>().InstancePerLifetimeScope();
builder.RegisterType<ShippingService>().As<IShippingService>().InstancePerLifetimeScope(); builder.RegisterType<TaxCategoryService>().As<ITaxCategoryService>().InstancePerLifetimeScope();
builder.RegisterType<TaxService>().As<ITaxService>().InstancePerLifetimeScope(); builder.RegisterType<DefaultLogger>().As<ILogger>().InstancePerLifetimeScope(); //use static cache (between HTTP requests)
builder.RegisterType<CustomerActivityService>().As<ICustomerActivityService>()
.WithParameter(ResolvedParameter.ForNamed<ICacheManager>("nop_cache_static"))
.InstancePerLifetimeScope(); bool databaseInstalled = DataSettingsHelper.DatabaseIsInstalled();
if (!databaseInstalled)
{
//installation service
if (config.UseFastInstallationService)
{
builder.RegisterType<SqlFileInstallationService>().As<IInstallationService>().InstancePerLifetimeScope();
}
else
{
builder.RegisterType<CodeFirstInstallationService>().As<IInstallationService>().InstancePerLifetimeScope();
}
} builder.RegisterType<ForumService>().As<IForumService>().InstancePerLifetimeScope(); builder.RegisterType<PollService>().As<IPollService>().InstancePerLifetimeScope();
builder.RegisterType<BlogService>().As<IBlogService>().InstancePerLifetimeScope();
builder.RegisterType<WidgetService>().As<IWidgetService>().InstancePerLifetimeScope();
builder.RegisterType<TopicService>().As<ITopicService>().InstancePerLifetimeScope();
builder.RegisterType<NewsService>().As<INewsService>().InstancePerLifetimeScope(); builder.RegisterType<DateTimeHelper>().As<IDateTimeHelper>().InstancePerLifetimeScope();
builder.RegisterType<SitemapGenerator>().As<ISitemapGenerator>().InstancePerLifetimeScope();
builder.RegisterType<PageHeadBuilder>().As<IPageHeadBuilder>().InstancePerLifetimeScope(); builder.RegisterType<ScheduleTaskService>().As<IScheduleTaskService>().InstancePerLifetimeScope(); builder.RegisterType<ExportManager>().As<IExportManager>().InstancePerLifetimeScope();
builder.RegisterType<ImportManager>().As<IImportManager>().InstancePerLifetimeScope();
builder.RegisterType<PdfService>().As<IPdfService>().InstancePerLifetimeScope();
builder.RegisterType<ThemeProvider>().As<IThemeProvider>().InstancePerLifetimeScope();
builder.RegisterType<ThemeContext>().As<IThemeContext>().InstancePerLifetimeScope(); builder.RegisterType<ExternalAuthorizer>().As<IExternalAuthorizer>().InstancePerLifetimeScope();
builder.RegisterType<OpenAuthenticationService>().As<IOpenAuthenticationService>().InstancePerLifetimeScope(); builder.RegisterType<RoutePublisher>().As<IRoutePublisher>().SingleInstance(); //Register event consumers
var consumers = typeFinder.FindClassesOfType(typeof(IConsumer<>)).ToList();
foreach (var consumer in consumers)
{
builder.RegisterType(consumer)
.As(consumer.FindInterfaces((type, criteria) =>
{
var isMatch = type.IsGenericType && ((Type)criteria).IsAssignableFrom(type.GetGenericTypeDefinition());
return isMatch;
}, typeof(IConsumer<>)))
.InstancePerLifetimeScope();
}
builder.RegisterType<EventPublisher>().As<IEventPublisher>().SingleInstance();
builder.RegisterType<SubscriptionService>().As<ISubscriptionService>().SingleInstance(); }
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