属性注入因Autofac失败 [英] Property Injection fails with Autofac

问题描述

我正在将Autofac与MVC/Owin和WebApi一起使用.

I am using Autofac with MVC / Owin and WebApi.

使用Autofac文档后，我正在使用设置:

Following Autofac documentation I am using the setup:

public static void Run(IAppBuilder application) {

  ContainerBuilder builder = new ContainerBuilder();

  HttpConfiguration configuration = GlobalConfiguration.Configuration;

  builder.RegisterControllers(typeof(MvcApplication).Assembly);
  builder.RegisterModelBinders(typeof(MvcApplication).Assembly);
  builder.RegisterModelBinderProvider();
  builder.RegisterModule<AutofacWebTypesModule>();
  builder.RegisterSource(new ViewRegistrationSource());
  builder.RegisterFilterProvider();
  builder.RegisterApiControllers(typeof(MvcApplication).Assembly);
  builder.RegisterWebApiFilterProvider(configuration);

  builder.RegisterType<Test>().As<ITest>().PropertiesAutowired();        

  IContainer container = builder.Build();
  application.UseAutofacMiddleware(container);
  DependencyResolver.SetResolver(new AutofacDependencyResolver(container));
  configuration.DependencyResolver = new AutofacWebApiDependencyResolver(container);

}

然后我在控制器上测试了构造函数和属性注入:

I then tested constructor and property injection on a controller:

public interface ITest { }
public class Test : ITest { }

public partial class HomeController : Controller {

  private ITest _testConstructor { get; set; }
  public ITest TestProperty { get; set; }

  public HomeController(ITest testConstructor) {

    _testConstructor = testConstructor;

  }

  public virtual ActionResult Index() {
    var test = TestProperty;
  }
}

因此_testConstructor被注入，并且TestProperty始终为null.

So _testConstructor is injected and TestProperty is always null.

我什至在Index方法中检查了它的值，并且它为null ...

I even checked its value inside Index method and it is null ...

我在应用程序的不同部分尝试了不同的配置，并且属性注入始终失败...

I tried different configurations and in different parts of the application and Property injection always fails ...

有人可以帮我吗?

更新1

添加.PropertiesAutowired();到Controller的RegisterController工作，但不适用于ViewPages.

Adding .PropertiesAutowired(); to RegisterController work for controllers but not for ViewPages.

我正在如下使用ViewPageBase:

I am using a ViewPageBase as follows:

public abstract class ViewPageBase : WebViewPage {
  public ITest Test { get; set; }
} // ViewPageBase

public abstract class ViewPageBase<T> : WebViewPage<T> {
  public ITest Test { get; set; }
} // ViewPageBase

然后在Autofac设置中，我有:

And then in Autofac setup I have:

builder.RegisterSource(new ViewRegistrationSource());
builder.RegisterType<Test>().As<ITest>();
builder.RegisterType<WebViewPage>().PropertiesAutowired();
builder.RegisterGeneric(typeof(WebViewPage<>)).PropertiesAutowired();

但是当我在视图中访问测试"属性时，该属性为null.

But when I access Test properties in my views it is null.

为什么?

更新2

如果在我的布局视图中添加:

If in my layout view I add:

@{
  var test = DependencyResolver.Current.GetService<ITest>();
}

测试已正确解决...

test is resolved correctly ...

布局页面和Autofac可能是一个问题吗?

Maybe is this a problem with Layout Pages and Autofac?

更新3

我能够复制问题并在 https://github.com/mdmoura/MvcAutofac

如果您运行项目，则第二行代码的_Layout主页上将出现错误:

If you run the project there will be an error on _Layout master page on the second code line:

  @SettingsA.Get()
  @SettingsB.Get()

SettingsA使用DependencyResolver在ViewPagePage中解析，并且可以正常工作.

SettingsA is resolved in ViewPagePage using DependencyResolver and it works.

通过SettingsB，我正在尝试使用属性注入，但是没有运气.

With SettingsB i am trying to use Property Injection and no luck.

Autofac配置位于global.asax Application_Start中.

Autofac configuration is in global.asax Application_Start.

有人知道怎么了吗?

推荐答案

在 Autofac 中不会自动完成属性注入.您必须告诉 Autofac 在您的控制器注册上注入属性.

Properties injection is not done automatically in Autofac. You have to tell Autofac to inject properties on your controller registration.

builder.RegisterControllers(typeof(MvcApplication).Assembly)
       .PropertiesAutowired();

有关更多信息，请参见属性和方法注入关于自动装配属性.

See Property and Method Injection for more information on autowiring properties.

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