Caliburn Micro的简单注入器GetAllInstances抛出异常

Question

我曾在Simple Injector和Caliburn micro工作过，但已经有近2年的时间了。今天当我尝试创建一个简单的WPF应用程序。首先，我最终阅读了文档，因为两个库都做了很多更改。

我遇到了几个问题，如"视图找不到"，得到解决后，但现在我被一个奇怪的问题卡住了。尝试启用记录器和其他功能，但不知道是Caliburn micro的问题还是简单的注入器的问题。

这是我的bootstrapper类:

 internal class AppBootstrapper : BootstrapperBase
    {
        public static readonly Container ContainerInstance = new Container();
        public AppBootstrapper()
        {
            LogManager.GetLog = type => new DebugLogger(type);
            Initialize();
        }
        protected override void Configure()
        {
            ContainerInstance.Register<IWindowManager, WindowManager>();
            ContainerInstance.RegisterSingleton<IEventAggregator, EventAggregator>();
            ContainerInstance.Register<MainWindowViewModel, MainWindowViewModel>();
            ContainerInstance.Verify();
        }
        protected override void OnStartup(object sender, System.Windows.StartupEventArgs e)
        {
            DisplayRootViewFor<MainWindowViewModel>();
        }
        protected override IEnumerable<object> GetAllInstances(Type service)
        {
            // This line throwing is exception when running the application
            // Error: 
            // ---> An exception of type 'SimpleInjector.ActivationException' occurred in SimpleInjector.dll
            // ---> Additional information: No registration for type IEnumerable<MainWindowView> could be found. 
            // ---> No registration for type IEnumerable<MainWindowView> could be found. 
            return ContainerInstance.GetAllInstances(service);
        }
        protected override object GetInstance(System.Type service, string key)
        {
            return ContainerInstance.GetInstance(service);
        }
        protected override IEnumerable<Assembly> SelectAssemblies()
        {
            return new[] {
                    Assembly.GetExecutingAssembly()
                };
        }
        protected override void BuildUp(object instance)
        {
            var registration = ContainerInstance.GetRegistration(instance.GetType(), true);
            registration.Registration.InitializeInstance(instance);
        }
    }

不知道我在这里错过了什么?

Answer 1

Simple Injector v3包含了几个突破性的变化。你所困扰的是第98期的突破性变化。默认情况下，Simple Injector v3不再将未注册的集合解析为空集合。正如您所注意到的，这破坏了Caliburn的适配器。

要解决这个问题，您必须将GetAllInstances方法更改为以下内容:

protected override IEnumerable<object> GetAllInstances(Type service)
{
    IServiceProvider provider = ContainerInstance;
    Type collectionType = typeof(IEnumerable<>).MakeGenericType(service);
    var services = (IEnumerable<object>)provider.GetService(collectionType);
    return services ?? Enumerable.Empty<object>();
}