如何防止EF4动态加载所有程序集

本文关键字：程序集 加载 动态 何防止 EF4 | 更新日期: 2023-09-27 18:04:29

我们使用ClickOnce进行动态程序集加载。我最近在解决方案中的"模型"项目中添加了一个EF4模型。

应用程序不能使用app.config文件作为它的连接字符串，所以我使用EntityConnection创建ObjectContext。

应用程序逻辑工作完美，然而，当您在使用ClickOnce部署应用程序时创建ObjectContext的实例时，EF4试图动态加载所有相关的程序集以查找元数据。

这强制clickonce下载clickonce dll映射中的每个程序集!

下面是调用ObjectContext函数时的堆栈跟踪:

   at System.AppDomain.OnAssemblyResolveEvent(RuntimeAssembly assembly, String assemblyFullName)
   at System.Reflection.RuntimeAssembly._nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, RuntimeAssembly locationHint, StackCrawlMark& stackMark, Boolean throwOnFileNotFound, Boolean forIntrospection, Boolean suppressSecurityChecks)
   at System.Reflection.RuntimeAssembly.nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, RuntimeAssembly locationHint, StackCrawlMark& stackMark, Boolean throwOnFileNotFound, Boolean forIntrospection, Boolean suppressSecurityChecks)
   at System.Reflection.RuntimeAssembly.InternalLoadAssemblyName(AssemblyName assemblyRef, Evidence assemblySecurity, StackCrawlMark& stackMark, Boolean forIntrospection, Boolean suppressSecurityChecks)
   at System.Reflection.Assembly.Load(AssemblyName assemblyRef)
   at System.Data.Metadata.Edm.MetadataAssemblyHelper.SafeLoadReferencedAssembly(AssemblyName assemblyName)
   at System.Data.Metadata.Edm.MetadataAssemblyHelper.<GetNonSystemReferencedAssemblies>d__0.MoveNext()
   at System.Data.Metadata.Edm.DefaultAssemblyResolver.GetAllDiscoverableAssemblies()
   at System.Data.Metadata.Edm.DefaultAssemblyResolver.GetWildcardAssemblies()
   at System.Data.Metadata.Edm.MetadataArtifactLoaderCompositeResource.LoadResources(String assemblyName, String resourceName, ICollection`1 uriRegistry, MetadataArtifactAssemblyResolver resolver)
   at System.Data.Metadata.Edm.MetadataArtifactLoaderCompositeResource.CreateResourceLoader(String path, ExtensionCheck extensionCheck, String validExtension, ICollection`1 uriRegistry, MetadataArtifactAssemblyResolver resolver)
   at System.Data.Metadata.Edm.MetadataArtifactLoader.Create(String path, ExtensionCheck extensionCheck, String validExtension, ICollection`1 uriRegistry, MetadataArtifactAssemblyResolver resolver)
   at System.Data.Metadata.Edm.MetadataCache.SplitPaths(String paths)
   at System.Data.Common.Utils.Memoizer`2.<>c__DisplayClass2.<Evaluate>b__0()
   at System.Data.Common.Utils.Memoizer`2.Result.GetValue()
   at System.Data.Common.Utils.Memoizer`2.Evaluate(TArg arg)
   at System.Data.EntityClient.EntityConnection.GetMetadataWorkspace(Boolean initializeAllCollections)
   at System.Data.Objects.ObjectContext.RetrieveMetadataWorkspaceFromConnection()
   at System.Data.Objects.ObjectContext..ctor(EntityConnection connection, Boolean isConnectionConstructor)

我怎样才能防止EF4这样做?

谢谢!

在遵循Craig的建议之后，我现在能够创建ObjectContext的实例，而不需要加载所有的程序集。

但是，它现在在运行查询时尝试加载所有程序集。请参见下面的堆栈跟踪:

   at System.AppDomain.OnAssemblyResolveEvent(RuntimeAssembly assembly, String assemblyFullName)
   at System.Reflection.RuntimeAssembly._nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, RuntimeAssembly locationHint, StackCrawlMark& stackMark, Boolean throwOnFileNotFound, Boolean forIntrospection, Boolean suppressSecurityChecks)
   at System.Reflection.RuntimeAssembly.nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, RuntimeAssembly locationHint, StackCrawlMark& stackMark, Boolean throwOnFileNotFound, Boolean forIntrospection, Boolean suppressSecurityChecks)
   at System.Reflection.RuntimeAssembly.InternalLoadAssemblyName(AssemblyName assemblyRef, Evidence assemblySecurity, StackCrawlMark& stackMark, Boolean forIntrospection, Boolean suppressSecurityChecks)
   at System.Reflection.Assembly.Load(AssemblyName assemblyRef)
   at System.Data.Metadata.Edm.MetadataAssemblyHelper.SafeLoadReferencedAssembly(AssemblyName assemblyName)
   at System.Data.Metadata.Edm.MetadataAssemblyHelper.<GetNonSystemReferencedAssemblies>d__0.MoveNext()
   at System.Data.Metadata.Edm.ObjectItemCollection.ImplicitLoadViewsFromAllReferencedAssemblies(Assembly assembly)
   at System.Data.Mapping.StorageMappingItemCollection.ViewDictionary.SerializedCollectViewsFromReferencedAssemblies(MetadataWorkspace workspace, Dictionary`2 extentMappingViews)
   at System.Data.Mapping.StorageMappingItemCollection.ViewDictionary.SerializedGetGeneratedViews(EntityContainer container)
   at System.Data.Common.Utils.Memoizer`2.<>c__DisplayClass2.<Evaluate>b__0()
   at System.Data.Common.Utils.Memoizer`2.Result.GetValue()
   at System.Data.Common.Utils.Memoizer`2.Evaluate(TArg arg)
   at System.Data.Mapping.StorageMappingItemCollection.ViewDictionary.GetGeneratedView(EntitySetBase extent, MetadataWorkspace workspace, StorageMappingItemCollection storageMappingItemCollection)
   at System.Data.Metadata.Edm.MetadataWorkspace.GetGeneratedView(EntitySetBase extent)
   at System.Data.Query.PlanCompiler.PreProcessor.ExpandView(Node node, ScanTableOp scanTableOp, IsOfOp& typeFilter)
   at System.Data.Query.PlanCompiler.PreProcessor.ProcessScanTable(Node scanTableNode, ScanTableOp scanTableOp, IsOfOp& typeFilter)
   at System.Data.Query.PlanCompiler.PreProcessor.Visit(ScanTableOp op, Node n)
   at System.Data.Query.InternalTrees.ScanTableOp.Accept[TResultType](BasicOpVisitorOfT`1 v, Node n)
   at System.Data.Query.InternalTrees.BasicOpVisitorOfT`1.VisitNode(Node n)
   at System.Data.Query.PlanCompiler.SubqueryTrackingVisitor.VisitChildren(Node n)
   at System.Data.Query.PlanCompiler.SubqueryTrackingVisitor.VisitRelOpDefault(RelOp op, Node n)
   at System.Data.Query.PlanCompiler.PreProcessor.Visit(ProjectOp op, Node n)
   at System.Data.Query.InternalTrees.ProjectOp.Accept[TResultType](BasicOpVisitorOfT`1 v, Node n)
   at System.Data.Query.InternalTrees.BasicOpVisitorOfT`1.VisitNode(Node n)
   at System.Data.Query.PlanCompiler.SubqueryTrackingVisitor.VisitChildren(Node n)
   at System.Data.Query.InternalTrees.BasicOpVisitorOfNode.VisitDefault(Node n)
   at System.Data.Query.InternalTrees.BasicOpVisitorOfNode.VisitPhysicalOpDefault(PhysicalOp op, Node n)
   at System.Data.Query.InternalTrees.BasicOpVisitorOfT`1.Visit(PhysicalProjectOp op, Node n)
   at System.Data.Query.InternalTrees.PhysicalProjectOp.Accept[TResultType](BasicOpVisitorOfT`1 v, Node n)
   at System.Data.Query.InternalTrees.BasicOpVisitorOfT`1.VisitNode(Node n)
   at System.Data.Query.PlanCompiler.PreProcessor.Process()
   at System.Data.Query.PlanCompiler.PreProcessor.Process(PlanCompiler planCompilerState, StructuredTypeInfo& typeInfo)
   at System.Data.Query.PlanCompiler.PlanCompiler.Compile(List`1& providerCommands, ColumnMap& resultColumnMap, Int32& columnCount, Set`1& entitySets)
   at System.Data.EntityClient.EntityCommandDefinition..ctor(DbProviderFactory storeProviderFactory, DbCommandTree commandTree)
   at System.Data.EntityClient.EntityProviderServices.CreateCommandDefinition(DbProviderFactory storeProviderFactory, DbCommandTree commandTree)
   at System.Data.EntityClient.EntityProviderServices.CreateDbCommandDefinition(DbProviderManifest providerManifest, DbCommandTree commandTree)
   at System.Data.Common.DbProviderServices.CreateCommandDefinition(DbCommandTree commandTree)
   at System.Data.Objects.Internal.ObjectQueryExecutionPlan.Prepare(ObjectContext context, DbQueryCommandTree tree, Type elementType, MergeOption mergeOption, Span span, ReadOnlyCollection`1 compiledQueryParameters)
   at System.Data.Objects.EntitySqlQueryState.GetExecutionPlan(Nullable`1 forMergeOption)
   at System.Data.Objects.ObjectQuery`1.GetResults(Nullable`1 forMergeOption)
   at System.Data.Objects.ObjectQuery`1.System.Collections.Generic.IEnumerable<T>.GetEnumerator()
   at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)

我将感谢任何进一步的帮助!谢谢。

嗯，我认为如果使用*，它应该首先检查当前的程序集。99%的情况下都是正确的。加载每个单独的程序集，然后只检查当前程序集对我来说似乎是一个bug。

使用反射来加载每个dll应该是可选的。

我仍然有这个问题。包含公司所有业务逻辑的模型库正在其他地方使用(不是上面提到的原始ClickOnce应用程序)。这个库引用了水晶报告的dll，现在会导致EF4抛出一个reflecttypeloadeexception，因为那台机器没有安装水晶。

是的，这是没有*通配符和预先生成的视图。

真的没有办法显式地告诉EF4不要加载程序集(它真的不需要)吗?否则，看起来我将不得不完全放弃EF4。

如何防止EF4动态加载所有程序集

您应该在EF连接字符串中指定正确的程序集，而不是使用*通配符。

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