我正在按照以下教程学习快速编码。
Code First to a New Database
我已经完成了该教程的第4步,但当我尝试运行我的代码时出现了问题。我在以下代码中遇到了以下异常...
当我尝试检查db变量属性时,很多都有调试错误提示:“函数评估需要运行所有线程”。该代码正在我的本地数据库中创建数据库并插入值。
如果我删除类Blog和Post中的属性的虚拟限定符,则可以解决此问题。
我在其他项目中也遇到同样的异常。许多属性显示“函数评估需要运行所有线程”。
我正在使用Entity Framework 6.0。
编辑:
Blog是DbContext对象的属性,我在程序类的主函数中初始化了它。然后将博客添加到上下文中,并保存它。这将创建/更新数据库并插入给定的值。代码与示例链接中的相同。
[堆栈跟踪] 以下是我捕获的堆栈跟踪。
foreach (var item in query)
{
Console.WriteLine(item.Name);
}
{"Exception has been thrown by the target of an invocation."}
带有内部异常
{"Access is denied: 'CodeFastNewDatabase.Program+Blog'.":""}
当我尝试检查db变量属性时,很多都有调试错误提示:“函数评估需要运行所有线程”。该代码正在我的本地数据库中创建数据库并插入值。
如果我删除类Blog和Post中的属性的虚拟限定符,则可以解决此问题。
public virtual List<Post> Posts { get; set; }
public virtual Blog Blog { get; set; }
我在其他项目中也遇到同样的异常。许多属性显示“函数评估需要运行所有线程”。
我正在使用Entity Framework 6.0。
编辑:
Blog是DbContext对象的属性,我在程序类的主函数中初始化了它。然后将博客添加到上下文中,并保存它。这将创建/更新数据库并插入给定的值。代码与示例链接中的相同。
[堆栈跟踪] 以下是我捕获的堆栈跟踪。
at System.Environment.GetStackTrace(Exception e, Boolean needFileInfo)
at System.Environment.get_StackTrace()
at CodeFastNewDatabase.Program.Main(String[] args) in f:\Dropbox\Projects\visual studio 2012\Projects\CodeFastNewDatabase\CodeFastNewDatabase\Program.cs:line 32
at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading.ThreadHelper.ThreadStart()
以下是两个异常(外部和内部)的堆栈跟踪:
at System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor)
at System.Reflection.RuntimeMethodInfo.UnsafeInvokeInternal(Object obj, Object[] parameters, Object[] arguments)
at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
at System.Reflection.MethodBase.Invoke(Object obj, Object[] parameters)
at System.Data.Entity.Core.Common.Internal.Materialization.Translator.TranslateColumnMap(Translator translator, Type elementType, ColumnMap columnMap, MetadataWorkspace workspace, SpanIndex spanIndex, MergeOption mergeOption, Boolean streaming, Boolean valueLayer)
at System.Data.Entity.Core.Objects.Internal.ObjectQueryExecutionPlanFactory.Prepare(ObjectContext context, DbQueryCommandTree tree, Type elementType, MergeOption mergeOption, Boolean streaming, Span span, IEnumerable`1 compiledQueryParameters, AliasGenerator aliasGenerator)
at System.Data.Entity.Core.Objects.ELinq.ELinqQueryState.GetExecutionPlan(Nullable`1 forMergeOption)
at System.Data.Entity.Core.Objects.ObjectQuery`1.<>c__DisplayClassb.<GetResults>b__a()
at System.Data.Entity.Core.Objects.ObjectContext.ExecuteInTransaction[T](Func`1 func, IDbExecutionStrategy executionStrategy, Boolean startLocalTransaction, Boolean releaseConnectionOnSuccess)
at System.Data.Entity.Core.Objects.ObjectQuery`1.<>c__DisplayClassb.<GetResults>b__9()
at System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.Execute[TResult](Func`1 operation)
at System.Data.Entity.Core.Objects.ObjectQuery`1.GetResults(Nullable`1 forMergeOption)
at System.Data.Entity.Core.Objects.ObjectQuery`1.<System.Collections.Generic.IEnumerable<T>.GetEnumerator>b__0()
at System.Lazy`1.CreateValue()
at System.Lazy`1.LazyInitValue()
at System.Lazy`1.get_Value()
at System.Data.Entity.Internal.LazyEnumerator`1.MoveNext()
at CodeFastNewDatabase.Program.Main(String[] args) in f:\Dropbox\Projects\visual studio 2012\Projects\CodeFastNewDatabase\CodeFastNewDatabase\Program.cs:line 33
at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading.ThreadHelper.ThreadStart()
内部异常堆栈跟踪
at System.Reflection.Emit.TypeBuilder.TermCreateClass(RuntimeModule module, Int32 tk, ObjectHandleOnStack type)
at System.Reflection.Emit.TypeBuilder.CreateTypeNoLock()
at System.Reflection.Emit.TypeBuilder.CreateType()
at System.Data.Entity.Core.Objects.Internal.EntityProxyFactory.ProxyTypeBuilder.CreateType(ModuleBuilder moduleBuilder)
at System.Data.Entity.Core.Objects.Internal.EntityProxyFactory.BuildType(ModuleBuilder moduleBuilder, ClrEntityType ospaceEntityType, MetadataWorkspace workspace)
at System.Data.Entity.Core.Objects.Internal.EntityProxyFactory.TryCreateProxyType(EntityType ospaceEntityType, MetadataWorkspace workspace)
at System.Data.Entity.Core.Objects.Internal.EntityProxyFactory.GetProxyType(ClrEntityType ospaceEntityType, MetadataWorkspace workspace)
at System.Data.Entity.Core.Common.Internal.Materialization.Translator.TranslatorVisitor.Visit(EntityColumnMap columnMap, TranslatorArg arg)
at System.Data.Entity.Core.Query.InternalTrees.EntityColumnMap.Accept[TResultType,TArgType](ColumnMapVisitorWithResults`2 visitor, TArgType arg)
at System.Data.Entity.Core.Common.Internal.Materialization.Translator.TranslatorVisitor.ProcessCollectionColumnMap(CollectionColumnMap columnMap, TranslatorArg arg, ColumnMap discriminatorColumnMap, Object discriminatorValue)
at System.Data.Entity.Core.Common.Internal.Materialization.Translator.TranslatorVisitor.ProcessCollectionColumnMap(CollectionColumnMap columnMap, TranslatorArg arg)
at System.Data.Entity.Core.Common.Internal.Materialization.Translator.TranslatorVisitor.Visit(SimpleCollectionColumnMap columnMap, TranslatorArg arg)
at System.Data.Entity.Core.Query.InternalTrees.SimpleCollectionColumnMap.Accept[TResultType,TArgType](ColumnMapVisitorWithResults`2 visitor, TArgType arg)
at System.Data.Entity.Core.Common.Internal.Materialization.Translator.TranslateColumnMap[T](ColumnMap columnMap, MetadataWorkspace workspace, SpanIndex spanIndex, MergeOption mergeOption, Boolean streaming, Boolean valueLayer)
Blog
类型?并能否发布完整的堆栈跟踪? - Jon SkeetEnvironment.StackTrace
。异常应该已经包含了完整的细节。 - Jon SkeetBlog
和Post
放在Program
声明的下方 - 但看起来你把它们放在了Program
的声明内部。我不知道这是否相关,但可能是这样。 - Jon Skeet