Visual Studio 2015（社区版）设计师在空白的通用应用程序中显示NullReferenceException错误

Question

我有些沮丧了，也许有人遇到过类似的问题或者有解决方法。

我升级到了 Windows 10。
我安装了 Visual Studio 2015 Community。
我创建了一个新的解决方案，只有一个空的通用 Windows 应用程序项目。我使用的是 C#。

问题：我试图在设计器中打开 MainPage.xaml 文件，但是设计器无法加载。我在设计器窗口中得到了一个NullReferenceException。我尝试在 Blend 中打开它，结果相同。如 Visual Studio 所建议的，我尝试在选项菜单中关闭“在 XAML 设计器中运行项目代码”功能，但没有帮助。

然而，在设计器中打开其他 xaml 文件（WPF、Windows Phone 8 或 8.1 通用应用程序）没有问题。这个应用程序可以在本地机器和模拟器上运行，只有设计器出了点问题。

欢迎任何建议。

编辑

设计器窗口中的异常：

System.NullReferenceException
Object reference not set to an instance of an object.
   at Microsoft.VisualStudio.DesignTools.Platform.Metadata.MetadataStore.GetTypeConverter(Type type)
   at Microsoft.VisualStudio.DesignTools.WindowsXamlDesigner.WindowsUIXamlDesignTimeProperties.ResolveImplementation(IPlatformMetadata platformMetadata, DesignTimePropertyId neutralProperty, IType declaringType, PropertyChangedCallback callback)
   at Microsoft.VisualStudio.DesignTools.WindowsXamlDesigner.WindowsUIXamlDesignTimeProperties.RegisterProperty(IPropertyId neutralPropertyKey, IType declaringType, PropertyChangedCallback callback)
   at Microsoft.VisualStudio.DesignTools.WindowsXamlDesigner.WindowsUIXamlCommonDesignTimeProperties.Initialize(WindowsUIXamlDesignTimeProperties designTimeProperties)
   at Microsoft.VisualStudio.DesignTools.WindowsXamlDesigner.WindowsUIXamlDesignTimeProperties..ctor(IPlatformTypes platformMetadata)
   at Microsoft.VisualStudio.DesignTools.UniversalXamlDesigner.UniversalXamlPlatformMetadata.CreateDesignTimeProperties()
   at Microsoft.VisualStudio.DesignTools.WindowsXamlDesigner.Metadata.WindowsUIXamlPlatformMetadata.Initialize()
   at Microsoft.VisualStudio.DesignTools.WindowsXamlDesigner.WindowsStoreXamlPlatform.Initialize()
   at Microsoft.VisualStudio.DesignTools.Platform.PlatformCreatorBase.CreatePlatform(IPlatformReferenceAssemblyResolver referenceAssemblyResolver)
   at Microsoft.VisualStudio.DesignTools.Designer.Project.ProjectContextManager.GetProjectContext(IHostProject project, IPlatform platform, Boolean create)
   at Microsoft.VisualStudio.DesignTools.Designer.Project.ProjectContextManager.GetSourceItemContext(IHostSourceItem sourceItem)
   at Microsoft.VisualStudio.DesignTools.Designer.DesignerService.CreateDesigner(IHostSourceItem item, IHostTextEditor editor, CancellationToken cancelToken)
   at Microsoft.VisualStudio.DesignTools.DesignerContract.Isolation.Remoting.RemoteDesignerService.<>c__DisplayClass12_0.<Microsoft.VisualStudio.DesignTools.DesignerContract.Isolation.Remoting.IRemoteDesignerService.CreateDesigner>b__0(CancellationToken cancelToken)
   at Microsoft.VisualStudio.DesignTools.DesignerContract.Isolation.Remoting.RemoteDesignerService.<>c__DisplayClass6_0`1.<MarshalInWithCancellation>b__0()
   at Microsoft.VisualStudio.DesignTools.DesignerContract.Isolation.Remoting.STAMarshaler.Call.InvokeWorker()

System.NullReferenceException
Object reference not set to an instance of an object.

Server stack trace: 
   at Microsoft.VisualStudio.DesignTools.DesignerContract.Isolation.Remoting.STAMarshaler.WaitForCompletion(NestedCallContext nestedCallContext, BlockingCall call, WaitHandle timeoutSignal)
   at Microsoft.VisualStudio.DesignTools.DesignerContract.Isolation.Remoting.STAMarshaler.MarshalInSynchronous(Action action, Int32 targetApartmentId, CancellationToken cancelToken, CallModality callModality, String methodName, String filePath, Int32 lineNumber)
   at Microsoft.VisualStudio.DesignTools.DesignerContract.Isolation.Remoting.STAMarshaler.MarshalIn(Action action, Int32 targetApartmentId, CancellationToken cancelToken, CallSynchronizationMode syncMode, CallModality callModality, String methodName, String filePath, Int32 lineNumber)
   at Microsoft.VisualStudio.DesignTools.DesignerContract.Isolation.Remoting.ThreadMarshaler.MarshalIn(IRemoteObject targetObject, Action action, CancellationToken cancelToken, CallSynchronizationMode syncMode, CallModality callModality, ApartmentState apartmentState, String memberName, String filePath, Int32 lineNumber)
   at Microsoft.VisualStudio.DesignTools.DesignerContract.Isolation.Remoting.RemoteDesignerService.MarshalInWithCancellation[TResult](IRemoteCancellationToken remoteToken, Func`2 func, ApartmentState apartmentState)
   at Microsoft.VisualStudio.DesignTools.DesignerContract.Isolation.Remoting.RemoteDesignerService.Microsoft.VisualStudio.DesignTools.DesignerContract.Isolation.Remoting.IRemoteDesignerService.CreateDesigner(IRemoteHostProject remoteProject, IRemoteHostSourceItem remoteItem, IRemoteHostTextEditor remoteEditor, IRemoteCancellationToken remoteToken)
   at System.Runtime.Remoting.Messaging.StackBuilderSink._PrivateProcessMessage(IntPtr md, Object[] args, Object server, Object[]& outArgs)
   at System.Runtime.Remoting.Messaging.StackBuilderSink.SyncProcessMessage(IMessage msg)

Exception rethrown at [0]: 
   at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg)
   at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData& msgData, Int32 type)
   at Microsoft.VisualStudio.DesignTools.DesignerContract.Isolation.Remoting.IRemoteDesignerService.CreateDesigner(IRemoteHostProject remoteProject, IRemoteHostSourceItem remoteItem, IRemoteHostTextEditor remoteEditor, IRemoteCancellationToken cancelToken)
   at Microsoft.VisualStudio.DesignTools.DesignerContract.Isolation.Remoting.LocalDesignerService.CreateDesignerImpl(IRemoteDesignerService ds, IHostSourceItem item, IHostTextEditor editor, RemoteCancellationToken remoteCancelToken)
   at Microsoft.VisualStudio.DesignTools.DesignerContract.Isolation.Remoting.LocalDesignerService.<>c__DisplayClass14_0.<Microsoft.VisualStudio.DesignTools.DesignerContract.IDesignerService.CreateDesigner>b__0(IRemoteDesignerService ds, RemoteCancellationToken remoteToken)
   at Microsoft.VisualStudio.DesignTools.DesignerContract.Isolation.Remoting.LocalDesignerService.<>c__DisplayClass5_0`1.<MarshalOutWithCancellation>b__0(IRemoteDesignerService ds)
   at Microsoft.VisualStudio.DesignTools.DesignerContract.Isolation.Remoting.ThreadMarshaler.<>c__DisplayClass27_0`1.<MarshalOut>b__0()
   at Microsoft.VisualStudio.DesignTools.DesignerContract.Isolation.Remoting.STAMarshaler.Call.InvokeWorker()

System.NullReferenceException
Object reference not set to an instance of an object.
   at Microsoft.VisualStudio.DesignTools.DesignerContract.Isolation.Remoting.STAMarshaler.WaitForCompletion(NestedCallContext nestedCallContext, BlockingCall call, WaitHandle timeoutSignal)
   at Microsoft.VisualStudio.DesignTools.DesignerContract.Isolation.Remoting.STAMarshaler.MarshalOutSynchronous(Action action, Int32 targetApartmentId, WaitHandle aborted, WaitHandle timeoutSignal, CancellationToken cancelToken, String methodName, String filePath, Int32 lineNumber)
   at Microsoft.VisualStudio.DesignTools.DesignerContract.Isolation.Remoting.STAMarshaler.MarshalOut(Action action, Int32 targetApartmentId, WaitHandle aborted, CancellationToken cancelToken, CallSynchronizationMode syncMode, WaitHandle timeoutSignal, String methodName, String filePath, Int32 lineNumber)
   at Microsoft.VisualStudio.DesignTools.DesignerContract.Isolation.Remoting.ThreadMarshaler.MarshalOut[TValue](RemoteHandle`1 targetObject, Action action, CancellationToken cancelToken, CallSynchronizationMode syncMode, ApartmentState apartmentState, String methodName, String filePath, Int32 lineNumber)
   at Microsoft.VisualStudio.DesignTools.DesignerContract.Isolation.Remoting.ThreadMarshaler.MarshalOut[TValue](RemoteHandle`1 targetObject, Action`1 action, CancellationToken cancelToken, CallSynchronizationMode syncMode, ApartmentState apartmentState, String methodName, String filePath, Int32 lineNumber)
   at Microsoft.VisualStudio.DesignTools.DesignerContract.Isolation.Remoting.LocalDesignerService.MarshalOutWithCancellation[TResult](CancellationToken cancelToken, Func`3 func, ApartmentState apartmentState)
   at Microsoft.VisualStudio.DesignTools.DesignerContract.Isolation.Remoting.LocalDesignerService.Microsoft.VisualStudio.DesignTools.DesignerContract.IDesignerService.CreateDesigner(IHostSourceItem item, IHostTextEditor editor, CancellationToken cancelToken)
   at Microsoft.VisualStudio.DesignTools.DesignerContract.IsolatedDesignerService.IsolatedDesignerView.CreateDesignerViewInfo(CancellationToken cancelToken)

- Tenshiko

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将异常的完整堆栈信息发布。 - magicandre1981

如果尝试的答案不行，请在connect上报告：https://connect.microsoft.com/VisualStudio/feedback/ - magicandre1981

请查看这个其他的问题。那里列出的奇怪解决方案对我和其他人都有效。https://dev59.com/wo3da4cB1Zd3GeqP3bBm - William Jones

好奇一下，如果你在 Blend 中打开同一个项目会怎样呢？ - Justin XL

就像我之前提到的那样，在Blend中也是一样的。 ...这并不奇怪，毕竟从几个版本以来，理论上VS和Blend拥有相同的设计师。 - Tenshiko

Answer 1

如果您正在使用惠普电脑，这个方法对我有用：

在“系统” -> “高级系统设置” -> “环境变量”中删除“平台”环境变量...

在我的情况下，它显示为=HPD。

- sandorfalot

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是的，我确实在使用惠普电脑，删除环境变量解决了这个问题！ - Tenshiko

这个方法对我也有效。不知道你是怎么发现这个解决方案的。谢谢！ - CCamilo

这个可行！你是怎么想出来的？！ - instanceof

我很高兴它起作用了！我只是通过一些好的谷歌搜索找到了它。不知道那个人是如何想出来的，但我尝试了几种方法，最终找到了这个解决方案，尝试了一下，成功了！所以我觉得应该与那些遇到这个问题的人分享，因为挖掘它花费了一段时间。Google-fu，胜利在握。 - sandorfalot

Answer 2

您是否已经启用了设备的开发模式？在我启用之前，我也遇到了这个问题。

请进入设置，然后选择“更新和安全”，再选择“开发人员模式”，这样就可以了。

详细的说明请参考：https://msdn.microsoft.com/en-us/library/windows/apps/dn706236.aspx

希望这可以帮助您！

- Will V

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是的，我有。第一次尝试运行项目时，我收到了一个弹出窗口，告诉我必须打开开发者模式，所以我打开了它。 - Tenshiko

Answer 3

我通过Visual Studio向Microsoft报告了此问题，他们友善地给了我两个建议，其中一个起作用了，所以我想在这里分享一下：

1. 请查看以下已知问题，看看是否有助于解决您的问题： https://social.msdn.microsoft.com/Forums/en-US/f34da155-a4ad-4933-ba82-071de9c7c0b3/uwp-apps-fail-to-launch-and-xaml-designer-crashes-if-visual-studio-and-windows-store-apps-are-both?forum=Win10SDKToolsIssues

2. 如果这个方法不起作用，请尝试以下方法（根据需要替换路径）：

   icacls "c:\Program Files (x86)\Windows Kits\10\UnionMetadata\Windows.winmd" /grant *S-1-15-2-1:(RX)

请注意，我没有尝试第一个建议，因为它不适用于我，但第二个建议确实解决了我的问题。请确保在具有管理员权限的命令行提示符中运行上述命令。

希望这能帮助其他遇到同样问题的人。

- Thierry