Question

在VS2010中，打开Silverlight应用程序时出现以下错误：

System.NullReferenceException: Object reference not set to an instance of an object.
at Microsoft.Windows.Design.Platform.SilverlightMetadataContext.SilverlightXamlExtensionImplementations.<GetXmlNamespaceCompatibilityMappings>d__8.MoveNext()
at MS.Internal.Design.Metadata.ReflectionProjectNode.BuildSubsumption()
at MS.Internal.Design.Metadata.ReflectionProjectNode.SubsumingNamespace(Identifier identifier)
at MS.Internal.Design.Markup.XmlElement.BuildScope(PrefixScope parentScope, IParseContext context)
at MS.Internal.Design.Markup.XmlElement.ConvertToXaml(XamlElement parent, PrefixScope parentScope, IParseContext context, IMarkupSourceProvider provider)
at MS.Internal.Design.DocumentModel.DocumentTrees.Markup.XamlSourceDocument.FullParse(Boolean convertToXamlWithErrors)
at MS.Internal.Design.DocumentModel.DocumentTrees.Markup.XamlSourceDocument.get_RootItem()
at Microsoft.Windows.Design.DocumentModel.Trees.ModifiableDocumentTree.get_ModifiableRootItem()
at Microsoft.Windows.Design.DocumentModel.MarkupDocumentManagerBase.get_LoadState()
at MS.Internal.Host.PersistenceSubsystem.Load()
at MS.Internal.Host.Designer.Load()
at MS.Internal.Designer.VSDesigner.Load()
at MS.Internal.Designer.VSIsolatedDesigner.VSIsolatedView.Load()
at MS.Internal.Designer.VSIsolatedDesigner.VSIsolatedDesignerFactory.Load(IsolatedView view)
at MS.Internal.Host.Isolation.IsolatedDesigner.BootstrapProxy.LoadDesigner(IsolatedDesignerFactory factory, IsolatedView view)
at MS.Internal.Host.Isolation.IsolatedDesigner.BootstrapProxy.LoadDesigner(IsolatedDesignerFactory factory, IsolatedView view)
at MS.Internal.Host.Isolation.IsolatedDesigner.Load()
at MS.Internal.Designer.DesignerPane.LoadDesignerView()

现在我想说在我的电脑上安装了Microsoft Silverlight，Microsoft Silverlight 3 SDK和Microsoft Silverlight 4 SDK。在我使用Silverlight 3 SDK获得此异常的项目中。

我该如何解决这个问题？

Answer 1

检查你的xaml实现代码中的silverlight代码，似乎没有填充变量d__8，或者是null或没有引用它。

检查一下 http://social.msdn.microsoft.com/Forums/en/vswpfdesigner/thread/01ce533e-ed94-48d2-8184-e2e34e6bdc6f

Answer 2

用记事本打开* .csproj文件并检查以下行：

<ApplicationDefinition Include="App.xaml">
  <Generator>MSBuild:Compile</Generator>
  <SubType>Designer</SubType>
</ApplicationDefinition>

它必须存在于* .csproj文件中。

在打开silverlight应用程序时会发生异常

2 个答案: