Windows 10版本1903更新(NET Framework 4.8)打破棱镜6.3

Question

首先，我们很清楚这不是一个严格意义上的Prism 6.3的问题；我们正在寻找的(如果一个解决方案不是直接的)是指向问题的解决方案的指针--顺便说一句--这就是: Windows 10 version 1903，通过.NET -thanks 4.8的包含，打破了我们原本功能完善，久经考验的，基于生产部署的Prism 6.3的商业软件。我们使用的是棱镜(核心)、Prism.WPF和Prism.MEF (都是6.3版本)。每当我们尝试实例化一个已注册的视图时，我们得到的(后面的源代码)是以下运行时错误：

Prism.Regions.RegionNavigationService.CreateNewRegionItem(String candidateTargetContract)抛出InvalidOperationException: Cannot create navigation target 'xyzView'. Activation error ocurred while tring to get instance of type Object, key 'xyzView'.

内部异常源于Microsoft.Practices.ServiceLocation.ServiceLocatorImplBase.GetInstance(Type serviceType, String key)，它抛出一个ActivationException: Activation error ocurred while tring to get instance of type Object, key 'xyzView'.

这里有一些相关的代码(xyzView = ExpedicionView或ExpedicionMaestroView,都会触发异常)：

       [ModuleExport(typeof(ExpedicionModulo))]
       [Export(typeof(IMenu))]
       public class ExpedicionModulo : IModule, IMenu
       {    
            [Import]
            public IRegionManager RegionManager;    
            [Import]
            public ILoggerFacade Logger;
            [ImportingConstructor]
            public ExpedicionModulo(IRegionManager regionManager, ILoggerFacade logger)
            {
                Logger = logger;
                RegionManager = regionManager;
                // irrelevant (for our purposes) code omitted here
             }
            public void Initialize()
            {
                // Here's how we register views for main region   
                RegionManager.RegisterViewWithRegion(RegionNames.MainContentRegion, typeof(ExpedicionView));
                RegionManager.RegisterViewWithRegion(RegionNames.MainContentRegion, typeof(MaestroExpedicionView));
                // Some more registering for our dialog region
                RegionManager.RegisterViewWithRegion(RegionNames.DialogRegion, typeof(ExpedicionDetalleView));
                // other views registered in the very same fashion
                Logger.Log("Expedition Module initialized", Category.Info, Priority.None);
            }

我们在下面这段代码中调用RequestNavigate：

    [Export]
    [PartCreationPolicy(CreationPolicy.Shared)]
    public class ShellViewModel : BaseViewModel
    {
        public IRibbonPrincipal RibbonPrincipal { get; set; }

        private readonly InteractionRequest<Confirmation> _confirmationInteractionRequest;
        private readonly InteractionRequest<Notification> _notificationInteractionRequest;

        private string _seccionActiva;
        private string _subseccionActiva;

        private IRegionManager _regionManager;

        [ImportingConstructor]
        public ShellViewModel(IRegionManager regionManager, IEventAggregator eventAggregator, ILoggerFacade logger)
            : this(eventAggregator, logger)
        {
            try
            {
                _regionManager = regionManager;
                _regionManager.RegisterViewWithRegion(RegionNames.MainContentRegion, typeof(PrincipalView));
            }
            catch (Exception ex)
            {
                this.LoggerError(ex.Message);
            }
        }

        public ShellViewModel(IEventAggregator eventAggregator, ILoggerFacade logger)
            : base(eventAggregator, logger)
        {
            try
            {
                // Some irrelevant (to our purposes) initialization code omitted here
                New = new DelegateCommand(() => { }, () => { return false; }); // etc.                

                _confirmationInteractionRequest = new InteractionRequest<Confirmation>();
                _notificationInteractionRequest = new InteractionRequest<Notification>();

                // Events code omitted for brevity sake
                EventAggregator.GetEvent<MessageBoxEvent>().Subscribe(ShowMessageBox, ThreadOption.PublisherThread, false); // etc.                

                // View loading wireup 
                CambioSeccion = new DelegateCommand<object>(OnCambioSeccion);
                CambioSubseccion = new DelegateCommand<object[]>(OnCambioSubseccion);
                // some more irrelevant (to our purposes) code omitted here.
            }
            catch (Exception ex)
            {
                this.LoggerError(ex.Message);
            }
        }

        /// <summary>
        /// This is where we instantiate the View (WAI in .NET Framework <=4.7.2)
        /// </summary>
        /// <param name="objeto"></param>
        private void OnCambioSeccion(object objeto)
        {
            // Ribbon menu handling here
            RibbonPrincipal.ResetRibbon();

            IIdentifyViewModel ivm = null;

            // We are passing the View's name via clicked TreeViewItem in this case (param objeto)
            TreeViewItem treeViewItem = (TreeViewItem)objeto;

            if (treeViewItem != null && !string.IsNullOrEmpty(treeViewItem.Name))
            {
                _seccionActiva = treeViewItem.Name;

                // Now we build the actual RequestNavigate invoke
                // In our case, _seccionActiva would equal "Expedicion" or "MaestroExpedicion"
                _regionManager.RequestNavigate(RegionNames.MainContentRegion, new Uri("/" + _seccionActiva + "View", UriKind.Relative), (r) =>
                {
                    if (!r.Result.HasValue || !r.Result.Value)
                    {
                         // error handling code here
                    }
                    else
                    {                        
                        ivm = ((FrameworkElement)_regionManager.Regions[RegionNames.MainContentRegion].ActiveViews.First()).DataContext as IIdentifyViewModel;
                    }
                });

                // Some event triggering here
                if (ivm != null)
                {
                    Seccion.Cambio(EventAggregator, ivm.ID);
                }                
            }
        }

对于这篇长篇大论的帖子，很抱歉，并提前谢谢你。

Answer 1

@mcandal感谢您的撰写。这看起来像是我们在模式和实践激活代码中看到的.NET Framework4.8中引入的最新问题。潜在的问题是，在4.8中，类型的构造函数以不同的顺序返回，导致模式和实践选择第一个(例如。ctors)有时不再正确。当我们在即将发布的版本中修复时，有一些变通方法。此问题仅影响ngen的程序集。解决办法: 1)禁用包含以下类型的程序集的ngen：

 <configuration>
    <runtime>
      <disableNativeImageLoad>
        <assemblyIdentity name="assembly_name" />
      </disableNativeImageLoad>
    </runtime>
  </configuration>

2)对于被激活的类型，只有1个ctor (模式和实践的文档假设只有1个ctor) 3)选择其他提供的激活模型，您可以在其中传递参数的类型，以避免歧义。

正如我所提到的，我们正在努力修复，如果你想进一步讨论，你可以提交一个VS反馈项目并链接到这篇文章，我们可以在那里继续讨论。