c# - 为什么 Visual Studio 2019 UWP XAML 设计器显示空白屏幕？

Question

我正在试用 UWP，所以我下载了 Windows BuildCast UWP 测试应用程序，并且正在试用它，但完全无法使用 XAML 设计器！以下是错误（作为图像）
和文本〜

System.NullReferenceException
Object reference not set to an instance of an object.
   at Microsoft.VisualStudio.DesignTools.UwpSurfaceDesigner.Views.UwpIsolatedImageHost.UwpVisualWrapper.CreateWindowCore()
   at Microsoft.VisualStudio.DesignTools.XamlSurfaceDesigner.Views.DisabledHwndHolder.CreateHandle()
   at Microsoft.VisualStudio.DesignTools.UwpSurfaceDesigner.Views.UwpIsolatedImageHost.UwpVisualWrapper..ctor(IntPtr parentHwnd, IDCompositionDevice device, UwpSurfaceProcessDocument document, CancellationToken token)
   at Microsoft.VisualStudio.DesignTools.UwpSurfaceDesigner.Views.UwpIsolatedImageHost.UwpHwndHost.CreateSurfaceHwnd(IntPtr parentHwnd)
   at Microsoft.VisualStudio.DesignTools.XamlSurfaceDesigner.Views.IsolatedSurfaceImageHost.IsolatedHwndHost.BuildWindowCore(HandleRef hwndParent)
   at System.Windows.Interop.HwndHost.BuildWindow(HandleRef hwndParent)
   at System.Windows.Interop.HwndHost.BuildOrReparentWindow()
   at System.Windows.Interop.HwndHost.OnSourceChanged(Object sender, SourceChangedEventArgs e)
   at System.Windows.SourceChangedEventArgs.InvokeEventHandler(Delegate genericHandler, Object genericTarget)
   at System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target)
   at System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs)
   at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
   at System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args)
   at System.Windows.UIElement.RaiseEvent(RoutedEventArgs e)
   at System.Windows.PresentationSource.UpdateSourceOfElement(DependencyObject doTarget, DependencyObject doAncestor, DependencyObject doOldParent)
   at System.Windows.PresentationSource.OnVisualAncestorChanged(DependencyObject uie, AncestorChangedEventArgs e)
   at System.Windows.UIElement.OnVisualAncestorChanged(Object sender, AncestorChangedEventArgs e)
   at System.Windows.Media.Visual.ProcessAncestorChangedNotificationRecursive(DependencyObject e, AncestorChangedEventArgs args)
   at System.Windows.Media.Visual.FireOnVisualParentChanged(DependencyObject oldParent)
   at System.Windows.Media.Visual.AddVisualChild(Visual child)
   at System.Windows.Controls.Decorator.set_Child(UIElement value)
   at Microsoft.VisualStudio.DesignTools.XamlSurfaceDesigner.Views.IsolatedSurfaceImageHost.<CreateSurfaceAsync>d__66.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at Microsoft.VisualStudio.Telemetry.WindowsErrorReporting.WatsonReport.GetClrWatsonExceptionInfo(Exception exceptionObject)

System.AggregateException
One or more errors occurred.

我尝试了几件事-

1. Visual Studio 安装程序 -> 修复
2. 检查环境变量（HPD 或 MCD）
3. 以管理员身份运行 VS
4. 试图从预览频道获取 VS 来测试这一点
5. 切换后重新启动 Visual StudioShow XAML Designer
6. 将目标版本更改为至少 3 个不同的版本
   
   编辑：我尝试使用新的空白 UWP C# 应用程序，并收到此错误
   

标签： c#windowsvisual-studiouwp