SpecFlow:打开一个特性文件将生成一个NullReferenceException

Question

从几周以来，我突然对VisualStudio2019(专业版)中的SpecFlow扩展产生了问题。突然间它停止工作了。首先，我认为是因为VS的更新，但是我的其他同事正在使用相同(最新)版本的VS，而SpecFlow对他们来说是有效的。

我遇到的问题是：

打开功能文件时的

• 无设置菜单( SpecFlow (Tools - Options - SpecFlow)
• A NullReferenceException )

测试资源管理器仍然在发现测试，我仍然可以运行它们，但不能从特性文件中运行它们(也不能调试这些步骤)。

已正确安装并启用了扩展插件(据我所知)。已经尝试了以下方法，但没有成功：

extension

• Uninstall
• 卸载和安装SpecFlow for Visual 2019 SpecFlow SpecFlow和安装SpecFlow Visual 2019，然后再安装

你们中有谁知道是什么原因造成的？

活动日志条目

<entry>
  <record>806</record>
  <time>2021/02/09 09:25:56.786</time>
  <type>Error</type>
  <source>Editor or Editor Extension</source>
  <description>System.NullReferenceException: Object reference not set to an instance of an object.&#x000D;&#x000A;
    at TechTalk.SpecFlow.VsIntegration.LanguageService.ProjectScopeFactory.&lt;.ctor&gt;b__9_0() in D:\a\1\s\TechTalk.SpecFlow.VSIXShared\LanguageService\ProjectScopeFactory.cs:line 52&#x000D;&#x000A;
    at TechTalk.SpecFlow.VsIntegration.Implementation.Utils.SynchInitializedInstance`1.EnsureInitialized()&#x000D;&#x000A;
    at TechTalk.SpecFlow.VsIntegration.LanguageService.ProjectScopeFactory.&lt;.ctor&gt;b__9_2(Project project) in D:\a\1\s\TechTalk.SpecFlow.VSIXShared\LanguageService\ProjectScopeFactory.cs:line 64&#x000D;&#x000A;
    at TechTalk.SpecFlow.VsIntegration.Implementation.Utils.SynchronizedResultCache`3.GetOrCreate(TSource source)&#x000D;&#x000A;
    at TechTalk.SpecFlow.VsIntegration.LanguageService.ProjectScopeFactory.GetProjectScope(Project project) in D:\a\1\s\TechTalk.SpecFlow.VSIXShared\LanguageService\ProjectScopeFactory.cs:line 76&#x000D;&#x000A;
    at TechTalk.SpecFlow.VsIntegration.LanguageService.GherkinLanguageServiceFactory.CreateLanguageService(ITextBuffer textBuffer) in D:\a\1\s\TechTalk.SpecFlow.VSIXShared\LanguageService\GherkinLanguageServiceFactory.cs:line 51&#x000D;&#x000A;
    at TechTalk.SpecFlow.VsIntegration.LanguageService.GherkinLanguageServiceFactory.&lt;&gt;c__DisplayClass7_0.&lt;GetLanguageService&gt;b__0() in D:\a\1\s\TechTalk.SpecFlow.VSIXShared\LanguageService\GherkinLanguageServiceFactory.cs:line 43&#x000D;&#x000A;
    at TechTalk.SpecFlow.VsIntegration.LanguageService.GherkinBufferServiceManager.&lt;&gt;c__DisplayClass3_0`1.&lt;GetOrCreate&gt;b__0() in D:\a\1\s\TechTalk.SpecFlow.VSIXShared\LanguageService\GherkinBufferServiceManager.cs:line 32&#x000D;&#x000A;
    at Microsoft.VisualStudio.Utilities.PropertyCollection.GetOrCreateSingletonProperty[T](Object key, Func`1 creator)&#x000D;&#x000A;
    at TechTalk.SpecFlow.VsIntegration.LanguageService.GherkinBufferServiceManager.GetOrCreate[TService](ITextBuffer textBuffer, Func`1 creator) in D:\a\1\s\TechTalk.SpecFlow.VSIXShared\LanguageService\GherkinBufferServiceManager.cs:line 29&#x000D;&#x000A;
    at TechTalk.SpecFlow.VsIntegration.LanguageService.GherkinLanguageServiceFactory.GetLanguageService(ITextBuffer textBuffer) in D:\a\1\s\TechTalk.SpecFlow.VSIXShared\LanguageService\GherkinLanguageServiceFactory.cs:line 43&#x000D;&#x000A;
    at TechTalk.SpecFlow.VsIntegration.GherkinFileEditor.GherkinFileClassifierProvider.&lt;&gt;c__DisplayClass3_0.&lt;GetClassifier&gt;b__0() in D:\a\1\s\TechTalk.SpecFlow.VSIXShared\GherkinFileEditor\GherkinFileClassifierProvider.cs:line 31&#x000D;&#x000A;
    at TechTalk.SpecFlow.VsIntegration.LanguageService.GherkinBufferServiceManager.&lt;&gt;c__DisplayClass3_0`1.&lt;GetOrCreate&gt;b__0() in D:\a\1\s\TechTalk.SpecFlow.VSIXShared\LanguageService\GherkinBufferServiceManager.cs:line 32&#x000D;&#x000A;
    at Microsoft.VisualStudio.Utilities.PropertyCollection.GetOrCreateSingletonProperty[T](Object key, Func`1 creator)&#x000D;&#x000A;
    at TechTalk.SpecFlow.VsIntegration.LanguageService.GherkinBufferServiceManager.GetOrCreate[TService](ITextBuffer textBuffer, Func`1 creator) in D:\a\1\s\TechTalk.SpecFlow.VSIXShared\LanguageService\GherkinBufferServiceManager.cs:line 29&#x000D;&#x000A;
    at TechTalk.SpecFlow.VsIntegration.GherkinFileEditor.GherkinFileClassifierProvider.GetClassifier(ITextBuffer buffer) in D:\a\1\s\TechTalk.SpecFlow.VSIXShared\GherkinFileEditor\GherkinFileClassifierProvider.cs:line 30&#x000D;&#x000A;
    at Microsoft.VisualStudio.Text.Classification.Implementation.ClassifierTaggerProvider.&lt;&gt;c__DisplayClass12_0`1.&lt;CreateTagger&gt;b__0(IClassifierProvider provider)&#x000D;&#x000A;
    at Microsoft.VisualStudio.Text.Utilities.GuardedOperations.InvokeEligibleFactories[TExtensionInstance,TExtensionFactory,TMetadataView](IEnumerable`1 lazyFactories, Func`2 getter, IContentType dataContentType, IContentTypeRegistryService contentTypeRegistryService, Object errorSource)&#x000D;&#x000A;--- End of stack trace from previous location where exception was thrown ---&#x000D;&#x000A;
    at Microsoft.VisualStudio.Telemetry.WindowsErrorReporting.WatsonReport.GetClrWatsonExceptionInfo(Exception exceptionObject)
  </description>
</entry>

编辑:运行VS的修复后，我可以看到‘清除MEF组件缓存’扩展的菜单选项。不幸的是，在SpecFlow扩展(仍然是相同的问题)中，使用它并没有让我更进一步。

Answer 1

由于不同的问题，我收到了一个完整的新形象，我的笔记本电脑从IT部门。因此，SpecFlow的问题也得到了解决。我仍然不知道到底是什么原因造成了这种情况，但我的猜测可能会转到一个稍微损坏的注册表或类似的地方。

不管怎样，不用再回答这个问题了。

Answer 2

这看起来像Visual的MEF缓存有问题。

清理它的一个简单方法是来自Mads的Clear MEF Component Cache扩展。它可以在市场上找到：https://marketplace.visualstudio.com/items?itemName=MadsKristensen.ClearMEFComponentCache

安装它后，在VS重新启动后，在菜单中执行命令：

​

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在此之后，重新启动VS，并且SpecFlow VS扩展应该再次工作。