Question

我有一个ASP.NET MVC项目，其中包含2个数据库存储库接口（IDBSessionFactory）实例：一个用于数据数据库，另一个用于配置数据库。在我的Bootstrapper中，这就是我如何连接DI：

// using ...

builder.Register(c => new DbSessionFactory("dataDB", Assembly.GetExecutingAssembly()))
    .Named<IDbSessionFactory>("datadb")
    .InstancePerHttpRequest()
    .InstancePerApiRequest();

builder.Register(c => new DbSessionFactory("configDB", Assembly.GetExecutingAssembly()))
    .Named<IDbSessionFactory>("configdb")
    .InstancePerHttpRequest()
    .InstancePerApiRequest();

builder.RegisterControllers(Assembly.GetExecutingAssembly());

我有一些控制器类需要"configDB" IDBSessionFactory实例作为输入参数。我该如何实现这一目标？

感谢任何帮助。

Answer 1

我明白了。注册控制器时，必须使用命名参数。我的策略是根据datadb参数注册ALL控制器，然后根据configdb参数注册特定的控制器。唯一需要注意的是在所有控制器类中保持参数名称一致。

builder.RegisterControllers(Assembly.GetExecutingAssembly()).WithParameters(new[] { 
                        new ResolvedParameter((p, c) => p.Name == "dbSessionFactory", (p, c) => c.ResolveNamed<IDbSessionFactory>("datadb")) 
                    });

// Register controllers which need a specific named type            
builder.RegisterType<Web.Controllers.AdminController>().WithParameters(new[] { new ResolvedParameter((p, c) => p.Name == "sessionFactory", (p, c) => c.ResolveNamed<IDbSessionFactory>("configdb")) });
// Wire up the account controller with the config database instance, since all the user tables are there
builder.RegisterType<Web.Controllers.AccountController>().WithParameters(new[] { 
                        new ResolvedParameter((p, c) => p.Name == "dbSessionFactory", (p, c) => c.ResolveNamed<IDbSessionFactory>("configdb")) 
                        , new ResolvedParameter((p,c) => p.Name == "logger",(p,c) => c.Resolve<ILogger>())
                        , new ResolvedParameter((p,c) => p.Name == "formsAuth",(p,c) => c.Resolve<IFormsAuthentication>())
                    });

Answer 2

在Autofac中，注册是最后的胜利。这意味着，在您致电RegisterControllers后，您只需为要覆盖的控制器进行一次性注册即可生效。

示例：

builder.RegisterControllers(Assembly.GetExecutingAssembly()); builder.Register(c => new FooController(c.ResolveNamed<IDbSessionFactory>("configDB"))); // ... container.Resolve<FooController>() // Resolves FooController with configDB

Autofac - 注入接口的特定实例

2 个答案: