Question

我最近将我的项目升级到RxUI 7.0（从6.5开始）。启动我的UWP应用程序时，它会立即崩溃并出现以下异常：

System.TypeInitializationException: The type initializer for 'ReactiveUI.RxApp' threw an exception. ---> System.ArgumentNullException: Value cannot be null.
Parameter name: dispatcher

这是一个堆栈跟踪：

   at System.Reactive.Concurrency.CoreDispatcherScheduler..ctor(CoreDispatcher dispatcher)
   at System.Reactive.Concurrency.CoreDispatcherScheduler.get_Current()
   at ReactiveUI.PlatformRegistrations.<>c.<Register>b__0_5()
   at ReactiveUI.WaitForDispatcherScheduler.attemptToCreateScheduler()
   at ReactiveUI.PlatformRegistrations.Register(Action`2 registerFunction)
   at ReactiveUI.DependencyResolverMixins.InitializeReactiveUI(IMutableDependencyResolver resolver)
   at ReactiveUI.RxApp.<>c.<.cctor>b__0_0()
   at Splat.Locator.RegisterResolverCallbackChanged(Action callback)
   at ReactiveUI.RxApp..cctor()

这是另一个

   at ReactiveUI.RxApp.get_MainThreadScheduler()
   at ReactiveUI.ReactiveList`1.setupRx(IEnumerable`1 initialContents, Double resetChangeThreshold, IScheduler scheduler)
   at ReactiveUI.ReactiveList`1..ctor()
   at NewBooru.ViewModels.HamburgerViewModel..ctor()
   at NewBooru.Views.MainPage..ctor()
   at NewBooru.NewBooru_XamlTypeInfo.XamlTypeInfoProvider.Activate_31_MainPage()
   at NewBooru.NewBooru_XamlTypeInfo.XamlUserType.ActivateInstance()

崩溃的代码：

 public HamburgerViewModel()
        {
            MenuItems = new ReactiveList<MenuItem>
            {
                new MenuItem("link", "name", enum)
            };
        }

我无法想象这会因单元测试或任何手动测试而滑落。我是否需要在新版本中进行额外的初始化？

Answer 1

事实证明，问题是应用程序的核心Dispatcher在App的OnLaunched之前没有初始化。 ReactiveUI期望Dispatcher处于活动状态，如果不存在则会失败。 Here's a link在ReactiveUI repo中跟踪此问题。

解决方案是等待从ReactiveUI调用任何内容，直到应用程序触发OnLaunched为止。

RxApp CoreDispatcherScheduler为null

1 个答案: