c# - Autofac 依赖注入(inject)在 Debug 中有效，但在 Release 中崩溃

Question

什么会导致我的 DI 在 Debug模式下正常但在 Release模式下崩溃？这是一个 Xamarin.Forms 应用程序，正在 Android 上运行。

07-23 20:56:53.002 I/MonoDroid(15451): UNHANDLED EXCEPTION: Autofac.Core.DependencyResolutionException: An exception was thrown while executing a resolve operation. See the InnerException for details. ---> Object reference not set to an instance of an object (See inner exception for details.) ---> System.NullReferenceException: Object reference not set to an instance of an object
07-23 20:56:53.002 I/MonoDroid(15451):   at System.Linq.Expressions.Expression.CreateLambda (System.Type delegateType, System.Linq.Expressions.Expression body, System.String name, Boolean tailCall, System.Collections.ObjectModel.ReadOnlyCollection`1 parameters) [0x00000] in <filename unknown>:0 
07-23 20:56:53.002 I/MonoDroid(15451):   at System.Linq.Expressions.Expression.Lambda (System.Type delegateType, System.Linq.Expressions.Expression body, System.String name, Boolean tailCall, IEnumerable`1 parameters) [0x00000] in <filename unknown>:0 
07-23 20:56:53.002 I/MonoDroid(15451):   at System.Linq.Expressions.Expression.Lambda (System.Type delegateType, System.Linq.Expressions.Expression body, IEnumerable`1 parameters) [0x00000] in <filename unknown>:0 
07-23 20:56:53.002 I/MonoDroid(15451):   at Autofac.Features.GeneratedFactories.FactoryGenerator.CreateGenerator (System.Func`3 makeResolveCall, System.Type delegateType, ParameterMapping pm) [0x00000] in <filename unknown>:0 
07-23 20:56:53.002 I/MonoDroid(15451):   at Autofac.Features.GeneratedFactories.FactoryGenerator..ctor (System.Type delegateType, IComponentRegistration productRegistration, ParameterMapping parameterMapping) [0x00000] in <filename unknown>:0 
07-23 20:56:53.002 I/MonoDroid(15451):   at Autofac.Features.GeneratedFactories.GeneratedFactoryRegistrationSource+<>c__DisplayClass2.<RegistrationsFor>b__0 (IComponentRegistration r) [0x00000] in <filename unknown>:0 
07-23 20:56:53.002 I/MonoDroid(15451):   at System.Linq.Enumerable+<CreateSelectIterator>c__Iterator10`2[Autofac.Core.IComponentRegistration,Autofac.Core.IComponentRegistration].MoveNext () [0x00000] in <filename unknown>:0 
07-23 20:56:53.002 I/MonoDroid(15451):   at Autofac.Core.Registration.ComponentRegistry.GetInitializedServiceInfo (Autofac.Core.Service service) [0x00000] in <filename unknown>:0 
07-23 20:56:53.002 I/MonoDroid(15451):   at Autofac.Core.Registration.ComponentRegistry.TryGetRegistration (Autofac.Core.Service service, IComponentRegistration& registration) [0x00000] in <filename unknown>:0 
07-23 20:56:53.002 I/MonoDroid(15451):   at Autofac.Core.Activators.Reflection.AutowiringParameter.CanSupplyValue (System.Reflection.ParameterInfo pi, IComponentContext context, System.Func`1& valueProvider) [0x00000] in <filename unknown>:0 
07-23 20:56:53.002 I/MonoDroid(15451):   at Autofac.Core.Activators.Reflection.ConstructorParameterBinding..ctor (System.Reflection.ConstructorInfo ci, IEnumerable`1 availableParameters, IComponentContext context) [0x00000] in <filename unknown>:0 
07-23 20:56:53.002 I/MonoDroid(15451):   at Autofac.Core.Activators.Reflection.ReflectionActivator+<>c__DisplayClass5.<GetConstructorBindings>b__4 (System.Reflection.ConstructorInfo ci) [0x00000] in <filename unknown>:0 
07-23 20:56:53.002 I/MonoDroid(15451):   at System.Linq.Enumerable+<CreateSelectIterator>c__Iterator10`2[System.Reflection.ConstructorInfo,Autofac.Core.Activators.Reflection.ConstructorParameterBinding].MoveNext () [0x00000] in <filename unknown>:0 
07-23 20:56:53.002 I/MonoDroid(15451):   at System.Linq.Enumerable+<CreateWhereIterator>c__Iterator1E`1[Autofac.Core.Activators.Reflection.ConstructorParameterBinding].MoveNext () [0x00000] in <filename unknown>:0 
07-23 20:56:53.002 I/MonoDroid(15451):   at System.Linq.Enumerable.ToArray[ConstructorParameterBinding] (IEnumerable`1 source) [0x00000] in <filename unknown>:0 
07-23 20:56:53.002 I/MonoDroid(15451):   at Autofac.Core.Activators.Reflection.ReflectionActivator.ActivateInstance (IComponentContext context, IEnumerable`1 parameters) [0x00000] in <filename unknown>:0 
07-23 20:56:53.002 I/MonoDroid(15451):   at Autofac.Core.Resolving.InstanceLookup.Activate (IEnumerable`1 parameters) [0x00000] in <filename unknown>:0 
07-23 20:56:53.002 I/MonoDroid(15451):   at Autofac.Core.Resolving.InstanceLookup.Execute () [0x00000] in <filename unknown>:0 
07-23 20:56:53.002 I/MonoDroid(15451):   at Autofac.Core.Resolving.ResolveOperation.GetOrCreateInstance (ISharingLifetimeScope currentOperationScope, IComponentRegistration registration, IEnumerable`1 parameters) [0x00000] in <filename unknown>:0 
07-23 20:56:53.002 I/MonoDroid(15451):   at Autofac.Core.Resolving.ResolveOperation.ResolveComponent (IComponentRegistration registration, IEnumerable`1 parameters) [0x00000] in <filename unknown>:0 
07-23 20:56:53.002 I/MonoDroid(15451):   at Autofac.Core.Resolving.ResolveOperation.Execute (IComponentRegistration registration, IEnumerable`1 parameters) [0x00000] in <filename unknown>:0 
07-23 20:56:53.002 I/MonoDroid(15451):   -
Unhandled Exception:

Autofac.Core.DependencyResolutionException: An exception was thrown while executing a resolve operation. See the InnerException for details. ---> Object reference not set to an instance of an object (See inner exception for details.)

07-23 20:56:54.003 E/mono    (15451): 
07-23 20:56:54.003 E/mono    (15451): Unhandled Exception:
07-23 20:56:54.003 E/mono    (15451): Autofac.Core.DependencyResolutionException: An exception was thrown while executing a resolve operation. See the InnerException for details. ---> Object reference not set to an instance of an object (See inner exception for details.) ---> System.NullReferenceException: Object reference not set to an instance of an object
In mgmain JNI_OnLoad
07-23 20:56:54.003 E/mono    (15451):   at System.Linq.Expressions.Expression.CreateLambda (System.Type delegateType, System.Linq.Expressions.Expression body, System.String name, Boolean tailCall, System.Collections.ObjectModel.ReadOnlyCollection`1 parameters) [0x00000] in <filename unknown>:0 
07-23 20:56:54.003 E/mono    (15451):   at System.Linq.Expressions.Expression.Lambda (System.Type delegateType, System.Linq.Expressions.Expression body, System.String name, Boolean tailCall, IEnumerable`1 parameters) [0x00000] in <filename unknown>:0 
07-23 20:56:54.003 E/mono    (15451):   at System.Linq.Expressions.Expression.Lambda (System.Type delegateType, System.Linq.Expressions.Expression body, IEnumerable`1 parameters) [0x00000] in <filename unknown>:0 
07-23 20:56:54.003 E/mono    (15451):   at Autofac.Features.Generate
07-23 20:56:54.003 E/mono-rt (15451): [ERROR] FATAL UNHANDLED EXCEPTION: Autofac.Core.DependencyResolutionException: An exception was thrown while executing a resolve operation. See the InnerException for details. ---> Object reference not set to an instance of an object (See inner exception for details.) ---> System.NullReferenceException: Object reference not set to an instance of an object
07-23 20:56:54.003 E/mono-rt (15451):   at System.Linq.Expressions.Expression.CreateLambda (System.Type delegateType, System.Linq.Expressions.Expression body, System.String name, Boolean tailCall, System.Collections.ObjectModel.ReadOnlyCollection`1 parameters) [0x00000] in <filename unknown>:0 
07-23 20:56:54.003 E/mono-rt (15451):   at System.Linq.Expressions.Expression.Lambda (System.Type delegateType, System.Linq.Expressions.Expression body, System.String name, Boolean tailCall, IEnumerable`1 parameters) [0x00000] in <filename unknown>:0 
07-23 20:56:54.003 E/mono-rt (15451):   at System.Linq.Expressions.Expression.Lambda (System.Type delegateType, System.Linq.Expressions.Expression body, IEnumerable`1 parameters) [0x00000] in <filename unknown>:0 
07-23 20:56:54.003 E/mono-rt (15451):   at Autofac.Feat
The program 'Mono' has exited with code 0 (0x0).

我的构造函数的一个例子是这个

    public MainPage(Func<Action, Action<bool?>, MainMenu> mainMenu, 
                    ModulePage modulePage, 
                    LoadingPage loadingPage, 
                    Func<Action, AuthPage> authPage,
                    IUserDialogService userDialogService, 
                    IModuleService moduleService, 
                    ISyncCommand syncCommand)
    {
        _loadingPage = loadingPage;
        _authPage = authPage;
        _userDialogService = userDialogService;
        _moduleService = moduleService;
        _syncCommand = syncCommand;

        Title = Strings.app_title;
        var master = mainMenu(OnAfterDeauthenticated, OnToggleRequest());
        var detail = new NavigationPage(modulePage);

        if (App.Navigation == null)
        {
            App.Navigation = detail.Navigation;
        }

        Master = master;
        Detail = detail;
    }

ContainerBuilder 在 Android 应用程序中初始化，然后传递给 PCL。

安卓

    protected override void OnCreate(Bundle bundle)
    {
        base.OnCreate(bundle);

        Forms.Init(this, bundle);

        var container = RegisterDependencies();
        var page = App.GetMainPage(container);

        SetPage(page);
    }

    private static IContainer RegisterDependencies()
    {
        var containerBuilder = new ContainerBuilder();
        RegisterAndroidSpecific(containerBuilder);

        var coreIoc = new CoreIoC(containerBuilder);
        return coreIoc.Load();
    }

    private static void RegisterAndroidSpecific(ContainerBuilder containerBuilder)
    {
        containerBuilder.RegisterType<AudioPlayer>().SingleInstance().As<IAudioPlayer>();
        containerBuilder.RegisterType<SettingsService>().As<ISettingsService>();
        containerBuilder.RegisterType<NetworkService>().As<INetworkService>();
        containerBuilder.RegisterType<NativeVideoPlayer>().As<IVideoPlayer>();
        containerBuilder.RegisterType<MarkdownService>().As<IMarkdownService>();
        containerBuilder.RegisterType<UserDialogService>().As<IUserDialogService>();

        containerBuilder.RegisterType<DbProvider>()
            .SingleInstance()
            .WithParameters(new List<Parameter> {
                new TypedParameter(typeof(string), "fsm-breathingroom"),
                new TypedParameter(typeof(SqliteSettings), new SqliteSettings {
                    CacheSize = 16777216,
                    SyncMode = SynchronizationModes.Off,
                    JournalMode = SQLiteJournalModeEnum.Off,
                    PageSize = 65536
                })
            })
            .As<IDbProvider>();
    }

PCL

    public static Page GetMainPage(IContainer container)
    {
        Container = container;

        RegisterCurrentUser(Container.Resolve<UserModel>());
        RunMigrations();
        RegisterCurrentUser();

        var rootPage = Container.Resolve<MainPage>();
        return rootPage;
    }

Answer 1

这是 Mono Linker 中的一个错误，删除了 System.Core 中的一些代码，请参阅 https://bugzilla.xamarin.com/show_bug.cgi?id=22342 Xamarin 声称它已在 11/2014 的 master 中修复，但我无法验证它。应该与下一个稳定版本之一一起登陆。

作为解决方法，您可以从链接器项目->选项->Android 构建->链接器->忽略程序集中排除 System.Core。

或者，直接注册 Func 也可以:

builder.Register<Func<FooPage>>(c => () => new FooPage());