EntityFrameworkCore.InMemory System.ArgumentException
EntityFrameworkCore.InMemory System.ArgumentException
我正在 Microsoft Visual Studio Community 2017 中处理 ASP.NET 示例项目。我目前正在处理的项目昨天 运行 还不错。今天打开项目，立马收到消息框：
The project system has encountered an error.
An element with the same key but different value already exists. Key: Microsoft.EntityFrameworkCore.InMemory
A diagnostic log has been written:
=====================
Crippling
System.AggregateException: One or more errors occurred. ---> System.ArgumentException: An element with the same key but a different value already exists. Key: Microsoft.EntityFrameworkCore.InMemory
at System.Collections.Immutable.ImmutableDictionary`2.HashBucket.Add(TKey key, TValue value, IEqualityComparer`1 keyOnlyComparer, IEqualityComparer`1 valueComparer, KeyCollisionBehavior behavior, OperationResult& result)
at System.Collections.Immutable.ImmutableDictionary`2.AddRange(IEnumerable`1 items, MutationInput origin, KeyCollisionBehavior collisionBehavior)
at System.Collections.Immutable.ImmutableDictionary`2.AddRange(IEnumerable`1 pairs, Boolean avoidToHashMap)
at System.Collections.Immutable.ImmutableDictionary`2.AddRange(IEnumerable`1 pairs)
at Microsoft.VisualStudio.ProjectSystem.Designers.ProjectBuildSubscriptionService.UpdateRuleSnapshotCore(IProjectVersionedValue`1 source, String ruleName, IRule rule, ImmutableDictionary`2 items, ImmutableDictionary`2 properties, ImmutableList`1 recentItemRenames, IProjectChangeDiff& diff)
at Microsoft.VisualStudio.ProjectSystem.Designers.ProjectRuleSubscriptionServiceBase`1.UpdateSnapshotCoreAsync(TSource source, IImmutableSet`1 subscribedElements, IProjectVersionedValue`1 previousResult)
at Microsoft.VisualStudio.ProjectSystem.Designers.CustomizableBlockSubscriberBase`3.<UpdateSnapshotAsync>d__28.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.VisualStudio.ProjectSystem.Designers.CustomizableBlockSubscriberBase`3.<>c__DisplayClass27_0.<<Initialize>b__1>d.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.VisualStudio.Threading.JoinableTask.<JoinAsync>d__76.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.VisualStudio.Threading.JoinableTask`1.<JoinAsync>d__3.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.VisualStudio.ProjectSystem.Designers.CustomizableBlockSubscriberBase`3.<<Initialize>b__27_0>d.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.VisualStudio.ProjectSystem.DataflowExtensions.<>c__DisplayClass23_0`2.<<CreateSelfFilteringTransformBlock>b__0>d.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at Microsoft.VisualStudio.ProjectSystem.CommonProjectSystemTools.Rethrow(Exception ex)
at Microsoft.VisualStudio.ProjectSystem.ProjectErrorReporting.<>c__DisplayClass6_0.<SubmitErrorReport>b__0()
at Microsoft.VisualStudio.ProjectSystem.ExceptionFilter.<>c__DisplayClass2_0.<Guard>b__0()
at GuardMethodClass.GuardMethod(Func`1 , Func`2 , Func`2 )
--- End of inner exception stack trace ---
---> (Inner Exception #0) System.ArgumentException: An element with the same key but a different value already exists. Key: Microsoft.EntityFrameworkCore.InMemory
at System.Collections.Immutable.ImmutableDictionary`2.HashBucket.Add(TKey key, TValue value, IEqualityComparer`1 keyOnlyComparer, IEqualityComparer`1 valueComparer, KeyCollisionBehavior behavior, OperationResult& result)
at System.Collections.Immutable.ImmutableDictionary`2.AddRange(IEnumerable`1 items, MutationInput origin, KeyCollisionBehavior collisionBehavior)
at System.Collections.Immutable.ImmutableDictionary`2.AddRange(IEnumerable`1 pairs, Boolean avoidToHashMap)
at System.Collections.Immutable.ImmutableDictionary`2.AddRange(IEnumerable`1 pairs)
at Microsoft.VisualStudio.ProjectSystem.Designers.ProjectBuildSubscriptionService.UpdateRuleSnapshotCore(IProjectVersionedValue`1 source, String ruleName, IRule rule, ImmutableDictionary`2 items, ImmutableDictionary`2 properties, ImmutableList`1 recentItemRenames, IProjectChangeDiff& diff)
at Microsoft.VisualStudio.ProjectSystem.Designers.ProjectRuleSubscriptionServiceBase`1.UpdateSnapshotCoreAsync(TSource source, IImmutableSet`1 subscribedElements, IProjectVersionedValue`1 previousResult)
at Microsoft.VisualStudio.ProjectSystem.Designers.CustomizableBlockSubscriberBase`3.<UpdateSnapshotAsync>d__28.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.VisualStudio.ProjectSystem.Designers.CustomizableBlockSubscriberBase`3.<>c__DisplayClass27_0.<<Initialize>b__1>d.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.VisualStudio.Threading.JoinableTask.<JoinAsync>d__76.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.VisualStudio.Threading.JoinableTask`1.<JoinAsync>d__3.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.VisualStudio.ProjectSystem.Designers.CustomizableBlockSubscriberBase`3.<<Initialize>b__27_0>d.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.VisualStudio.ProjectSystem.DataflowExtensions.<>c__DisplayClass23_0`2.<<CreateSelfFilteringTransformBlock>b__0>d.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at Microsoft.VisualStudio.ProjectSystem.CommonProjectSystemTools.Rethrow(Exception ex)
at Microsoft.VisualStudio.ProjectSystem.ProjectErrorReporting.<>c__DisplayClass6_0.<SubmitErrorReport>b__0()
at Microsoft.VisualStudio.ProjectSystem.ExceptionFilter.<>c__DisplayClass2_0.<Guard>b__0()
at GuardMethodClass.GuardMethod(Func`1 , Func`2 , Func`2 )<---
===================
它还导致了一些其他问题，例如我对系统和 Microsoft 命名空间的所有使用指令都出现错误：
The type or namespace name 'System' could be found (are you missing a using directive or an assembly reference?)
由于这些指令对其他项目仍然有效，我怀疑当 EntityFramework 问题解决后它们会消退。
我已经尝试重新启动 Visual Studio 和我的计算机，并且仍然尝试构建项目。我无法添加对该项目的引用。我收到消息框：
A task was canceled
The operation could not be completed
对项目中命名空间的引用仍然正常工作。
感谢您的帮助。
关闭VS.
通过以下方式打开您的项目文件（csproj 文件或 project.json）
外部文本编辑器并删除重复的包引用。
重开VS。一切正常。
如果使用 csproj 文件格式 - 查找如下行：
<PackageReference Include="Microsoft.EntityFrameworkCore.InMemory" Version="1.1.1" />
我正在 Microsoft Visual Studio Community 2017 中处理 ASP.NET 示例项目。我目前正在处理的项目昨天 运行 还不错。今天打开项目，立马收到消息框：
The project system has encountered an error.
An element with the same key but different value already exists. Key: Microsoft.EntityFrameworkCore.InMemory
A diagnostic log has been written:
=====================
Crippling
System.AggregateException: One or more errors occurred. ---> System.ArgumentException: An element with the same key but a different value already exists. Key: Microsoft.EntityFrameworkCore.InMemory
at System.Collections.Immutable.ImmutableDictionary`2.HashBucket.Add(TKey key, TValue value, IEqualityComparer`1 keyOnlyComparer, IEqualityComparer`1 valueComparer, KeyCollisionBehavior behavior, OperationResult& result)
at System.Collections.Immutable.ImmutableDictionary`2.AddRange(IEnumerable`1 items, MutationInput origin, KeyCollisionBehavior collisionBehavior)
at System.Collections.Immutable.ImmutableDictionary`2.AddRange(IEnumerable`1 pairs, Boolean avoidToHashMap)
at System.Collections.Immutable.ImmutableDictionary`2.AddRange(IEnumerable`1 pairs)
at Microsoft.VisualStudio.ProjectSystem.Designers.ProjectBuildSubscriptionService.UpdateRuleSnapshotCore(IProjectVersionedValue`1 source, String ruleName, IRule rule, ImmutableDictionary`2 items, ImmutableDictionary`2 properties, ImmutableList`1 recentItemRenames, IProjectChangeDiff& diff)
at Microsoft.VisualStudio.ProjectSystem.Designers.ProjectRuleSubscriptionServiceBase`1.UpdateSnapshotCoreAsync(TSource source, IImmutableSet`1 subscribedElements, IProjectVersionedValue`1 previousResult)
at Microsoft.VisualStudio.ProjectSystem.Designers.CustomizableBlockSubscriberBase`3.<UpdateSnapshotAsync>d__28.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.VisualStudio.ProjectSystem.Designers.CustomizableBlockSubscriberBase`3.<>c__DisplayClass27_0.<<Initialize>b__1>d.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.VisualStudio.Threading.JoinableTask.<JoinAsync>d__76.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.VisualStudio.Threading.JoinableTask`1.<JoinAsync>d__3.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.VisualStudio.ProjectSystem.Designers.CustomizableBlockSubscriberBase`3.<<Initialize>b__27_0>d.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.VisualStudio.ProjectSystem.DataflowExtensions.<>c__DisplayClass23_0`2.<<CreateSelfFilteringTransformBlock>b__0>d.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at Microsoft.VisualStudio.ProjectSystem.CommonProjectSystemTools.Rethrow(Exception ex)
at Microsoft.VisualStudio.ProjectSystem.ProjectErrorReporting.<>c__DisplayClass6_0.<SubmitErrorReport>b__0()
at Microsoft.VisualStudio.ProjectSystem.ExceptionFilter.<>c__DisplayClass2_0.<Guard>b__0()
at GuardMethodClass.GuardMethod(Func`1 , Func`2 , Func`2 )
--- End of inner exception stack trace ---
---> (Inner Exception #0) System.ArgumentException: An element with the same key but a different value already exists. Key: Microsoft.EntityFrameworkCore.InMemory
at System.Collections.Immutable.ImmutableDictionary`2.HashBucket.Add(TKey key, TValue value, IEqualityComparer`1 keyOnlyComparer, IEqualityComparer`1 valueComparer, KeyCollisionBehavior behavior, OperationResult& result)
at System.Collections.Immutable.ImmutableDictionary`2.AddRange(IEnumerable`1 items, MutationInput origin, KeyCollisionBehavior collisionBehavior)
at System.Collections.Immutable.ImmutableDictionary`2.AddRange(IEnumerable`1 pairs, Boolean avoidToHashMap)
at System.Collections.Immutable.ImmutableDictionary`2.AddRange(IEnumerable`1 pairs)
at Microsoft.VisualStudio.ProjectSystem.Designers.ProjectBuildSubscriptionService.UpdateRuleSnapshotCore(IProjectVersionedValue`1 source, String ruleName, IRule rule, ImmutableDictionary`2 items, ImmutableDictionary`2 properties, ImmutableList`1 recentItemRenames, IProjectChangeDiff& diff)
at Microsoft.VisualStudio.ProjectSystem.Designers.ProjectRuleSubscriptionServiceBase`1.UpdateSnapshotCoreAsync(TSource source, IImmutableSet`1 subscribedElements, IProjectVersionedValue`1 previousResult)
at Microsoft.VisualStudio.ProjectSystem.Designers.CustomizableBlockSubscriberBase`3.<UpdateSnapshotAsync>d__28.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.VisualStudio.ProjectSystem.Designers.CustomizableBlockSubscriberBase`3.<>c__DisplayClass27_0.<<Initialize>b__1>d.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.VisualStudio.Threading.JoinableTask.<JoinAsync>d__76.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.VisualStudio.Threading.JoinableTask`1.<JoinAsync>d__3.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.VisualStudio.ProjectSystem.Designers.CustomizableBlockSubscriberBase`3.<<Initialize>b__27_0>d.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.VisualStudio.ProjectSystem.DataflowExtensions.<>c__DisplayClass23_0`2.<<CreateSelfFilteringTransformBlock>b__0>d.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at Microsoft.VisualStudio.ProjectSystem.CommonProjectSystemTools.Rethrow(Exception ex)
at Microsoft.VisualStudio.ProjectSystem.ProjectErrorReporting.<>c__DisplayClass6_0.<SubmitErrorReport>b__0()
at Microsoft.VisualStudio.ProjectSystem.ExceptionFilter.<>c__DisplayClass2_0.<Guard>b__0()
at GuardMethodClass.GuardMethod(Func`1 , Func`2 , Func`2 )<---
===================
它还导致了一些其他问题，例如我对系统和 Microsoft 命名空间的所有使用指令都出现错误：
The type or namespace name 'System' could be found (are you missing a using directive or an assembly reference?)
由于这些指令对其他项目仍然有效，我怀疑当 EntityFramework 问题解决后它们会消退。
我已经尝试重新启动 Visual Studio 和我的计算机，并且仍然尝试构建项目。我无法添加对该项目的引用。我收到消息框：
A task was canceled
The operation could not be completed
对项目中命名空间的引用仍然正常工作。
感谢您的帮助。
关闭VS.
通过以下方式打开您的项目文件（
csproj文件或project.json） 外部文本编辑器并删除重复的包引用。重开VS。一切正常。
如果使用 csproj 文件格式 - 查找如下行：
<PackageReference Include="Microsoft.EntityFrameworkCore.InMemory" Version="1.1.1" />