C# 实体框架核心与实体框架的冲突

我已经在.NETFramework上为数据访问层创建了mssql数据库和项目（类库）。然后我在asp.net核心创建了这个项目。 要访问此数据库，我在

ConfigureServices

方法的启动类中使用。我在asp.net核心项目中使用EF核心

services.AddDbContext<TradeEvoDbContext>(options =>
    options.UseSqlServer(Configuration.GetConnectionString("SqlDb")));
 services.AddIdentity<ApplicationUser, IdentityRole>()
         .AddEntityFrameworkStores<TradeEvoDbContext>()
         .AddDefaultTokenProviders();

或：

我得到了下一个例外：

{System.IO.FileNotFoundException: Could not load file or assembly 'Microsoft.AspNet.Identity.EntityFramework, Version=2.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35'. File can not be found.
File name: 'Microsoft.AspNet.Identity.EntityFramework, Version=2.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35'

所有stacktrace都是：

{System.IO.FileNotFoundException: Could not load file or assembly 'Microsoft.AspNet.Identity.EntityFramework, Version=2.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35'. Не удается найти указанный файл.
File name: 'Microsoft.AspNet.Identity.EntityFramework, Version=2.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35'
   at System.Signature.GetSignature(Void* pCorSig, Int32 cCorSig, RuntimeFieldHandleInternal fieldHandle, IRuntimeMethodInfo methodHandle, RuntimeType declaringType)
   at System.Reflection.RuntimeMethodInfo.FetchNonReturnParameters()
   at System.Reflection.RuntimeMethodInfo.GetParametersNoCopy()
   at System.Reflection.RuntimePropertyInfo.GetIndexParametersNoCopy()
   at System.Reflection.RuntimePropertyInfo.GetIndexParameters()
   at System.Attribute.GetIndexParameterTypes(PropertyInfo element)
   at System.Attribute.InternalGetCustomAttributes(PropertyInfo element, Type type, Boolean inherit)
   at System.Reflection.CustomAttributeExtensions.GetCustomAttributes[T](MemberInfo element, Boolean inherit)
   at Microsoft.EntityFrameworkCore.Metadata.Conventions.Internal.NotMappedMemberAttributeConvention.Apply(InternalEntityTypeBuilder entityTypeBuilder)
   at Microsoft.EntityFrameworkCore.Metadata.Conventions.Internal.ConventionDispatcher.ImmediateConventionScope.OnEntityTypeAdded(InternalEntityTypeBuilder entityTypeBuilder)
   at Microsoft.EntityFrameworkCore.Metadata.Conventions.Internal.ConventionDispatcher.OnEntityTypeAdded(InternalEntityTypeBuilder entityTypeBuilder)
   at Microsoft.EntityFrameworkCore.Metadata.Internal.Model.AddEntityType(EntityType entityType)
   at Microsoft.EntityFrameworkCore.Metadata.Internal.Model.AddEntityType(Type type, ConfigurationSource configurationSource)
   at Microsoft.EntityFrameworkCore.Metadata.Internal.InternalModelBuilder.Entity(TypeIdentity type, ConfigurationSource configurationSource)
   at Microsoft.EntityFrameworkCore.Metadata.Internal.InternalModelBuilder.Entity(Type type, ConfigurationSource configurationSource)
   at Microsoft.EntityFrameworkCore.ModelBuilder.Entity(Type type)
   at Microsoft.EntityFrameworkCore.Infrastructure.ModelCustomizer.FindSets(ModelBuilder modelBuilder, DbContext context)
   at Microsoft.EntityFrameworkCore.Infrastructure.RelationalModelCustomizer.FindSets(ModelBuilder modelBuilder, DbContext context)
   at Microsoft.EntityFrameworkCore.Infrastructure.ModelCustomizer.Customize(ModelBuilder modelBuilder, DbContext context)
   at Microsoft.EntityFrameworkCore.Infrastructure.RelationalModelCustomizer.Customize(ModelBuilder modelBuilder, DbContext context)
   at Microsoft.EntityFrameworkCore.Infrastructure.ModelSource.CreateModel(DbContext context, IConventionSetBuilder conventionSetBuilder, IModelValidator validator)
   at Microsoft.EntityFrameworkCore.Infrastructure.ModelSource.<>c__DisplayClass5_0.<GetModel>b__0(Object k)
   at System.Collections.Concurrent.ConcurrentDictionary`2.GetOrAdd(TKey key, Func`2 valueFactory)
   at Microsoft.EntityFrameworkCore.Infrastructure.ModelSource.GetModel(DbContext context, IConventionSetBuilder conventionSetBuilder, IModelValidator validator)
   at Microsoft.EntityFrameworkCore.Internal.DbContextServices.CreateModel()
   at Microsoft.EntityFrameworkCore.Internal.DbContextServices.get_Model()
   at Microsoft.EntityFrameworkCore.Infrastructure.EntityFrameworkServicesBuilder.<>c.<TryAddCoreServices>b__7_1(IServiceProvider p)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitFactory(FactoryCallSite factoryCallSite, ServiceProvider provider)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor`2.VisitCallSite(IServiceCallSite callSite, TArgument argument)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitScoped(ScopedCallSite scopedCallSite, ServiceProvider provider)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor`2.VisitCallSite(IServiceCallSite callSite, TArgument argument)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitConstructor(ConstructorCallSite constructorCallSite, ServiceProvider provider)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor`2.VisitCallSite(IServiceCallSite callSite, TArgument argument)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitScoped(ScopedCallSite scopedCallSite, ServiceProvider provider)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor`2.VisitCallSite(IServiceCallSite callSite, TArgument argument)
   at Microsoft.Extensions.DependencyInjection.ServiceProvider.<>c__DisplayClass22_0.<RealizeService>b__0(ServiceProvider provider)
   at Microsoft.Extensions.DependencyInjection.ServiceProvider.GetService(Type serviceType)
   at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService(IServiceProvider provider, Type serviceType)
   at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService[T](IServiceProvider provider)
   at Microsoft.EntityFrameworkCore.DbContext.get_DbContextDependencies()
   at Microsoft.EntityFrameworkCore.DbContext.get_InternalServiceProvider()
   at Microsoft.EntityFrameworkCore.DbContext.get_DbContextDependencies()
   at Microsoft.EntityFrameworkCore.DbContext.get_Model()
   at Microsoft.EntityFrameworkCore.Internal.InternalDbSet`1.get_EntityType()
   at Microsoft.EntityFrameworkCore.Internal.InternalDbSet`1.get_EntityQueryable()
   at Microsoft.EntityFrameworkCore.Internal.InternalDbSet`1.System.Linq.IQueryable.get_Provider()
   at System.Linq.Queryable.Where[TSource](IQueryable`1 source, Expression`1 predicate)
   at TradeEvo.Chat.Controllers.HomeController.<ChatAsync>d__15.MoveNext() in myproj

编辑#2 发生了什么？

---

请在项目引用中检查“Microsoft.AspNet.Identity.EntityFramework”库的版本，并与同一库的web.config文件中的版本进行交叉验证。将web.config文件中的版本更改为项目中引用的库的正确版本。这将解决您的问题

您还可以在packages.config文件中检查版本

并在web.config中更新版本，如下所示

---

库引用隐式地包括该库引用的库。更简单地说，如果有引用EF 6的库X，并且包含引用EF核心的库Y。库Y将同时引用EF 6和EF core

---

您可以混合使用EF6/EF Core，但必须将它们彼此分离。如果您需要库中引用EF 6的部分，则必须将其拆分为独立的库，而不引用EF 6。

不要将ASP.NET标识与EF Core混用。可以将ASP.NET核心标识与EF核心一起使用，也可以将ASP.NET核心标识与EF核心一起使用EF6@Tseng，那么我是否需要将类库重新创建为.net core并在其中使用EF core？不，您也可以在.net Framework中使用ASP.net core和EF core。如果您想以Linux为目标或获得.NET Core的一些性能优势，您只需要.NET Core（运行时）/.NET标准。如果您有需要.NET Framework的旧式依赖项，请继续使用它，直到可以从中迁移it@qwiz否，您应该删除Microsoft.AspNet.Identity.EntityFramework。那是错误的包裹。这是一个用于非核心ASP.NET和EF@qwiz你为什么还要添加额外的软件包？ASP.NET核心项目模板已包含相应的包。您是否试图解决另一个问题，并认为缺少一个软件包？您正在强制降级，屏幕截图甚至与.NET Core无关。在.NET core中没有

package.config

。在发生库问题的地方创建了一个类库项目，它不在.NET core项目中。由于类库项目没有实体框架库，我假设它必须通过nuget manager添加。这将自动在类库项目中添加packages.config。在.NET Core中没有package.config、web.config或app.config。但是如何将DAL项目包括到asp.NET Core项目中？我是否需要创建新的DAL项目来访问.net core中的数据库？还是怎样

var user = await _userManager.Users.FindByIdAsync(args[1]);

{System.IO.FileNotFoundException: Could not load file or assembly 'Microsoft.AspNet.Identity.EntityFramework, Version=2.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35'. File can not be found.
File name: 'Microsoft.AspNet.Identity.EntityFramework, Version=2.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35'

{System.IO.FileNotFoundException: Could not load file or assembly 'Microsoft.AspNet.Identity.EntityFramework, Version=2.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35'. Не удается найти указанный файл.
File name: 'Microsoft.AspNet.Identity.EntityFramework, Version=2.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35'
   at System.Signature.GetSignature(Void* pCorSig, Int32 cCorSig, RuntimeFieldHandleInternal fieldHandle, IRuntimeMethodInfo methodHandle, RuntimeType declaringType)
   at System.Reflection.RuntimeMethodInfo.FetchNonReturnParameters()
   at System.Reflection.RuntimeMethodInfo.GetParametersNoCopy()
   at System.Reflection.RuntimePropertyInfo.GetIndexParametersNoCopy()
   at System.Reflection.RuntimePropertyInfo.GetIndexParameters()
   at System.Attribute.GetIndexParameterTypes(PropertyInfo element)
   at System.Attribute.InternalGetCustomAttributes(PropertyInfo element, Type type, Boolean inherit)
   at System.Reflection.CustomAttributeExtensions.GetCustomAttributes[T](MemberInfo element, Boolean inherit)
   at Microsoft.EntityFrameworkCore.Metadata.Conventions.Internal.NotMappedMemberAttributeConvention.Apply(InternalEntityTypeBuilder entityTypeBuilder)
   at Microsoft.EntityFrameworkCore.Metadata.Conventions.Internal.ConventionDispatcher.ImmediateConventionScope.OnEntityTypeAdded(InternalEntityTypeBuilder entityTypeBuilder)
   at Microsoft.EntityFrameworkCore.Metadata.Conventions.Internal.ConventionDispatcher.OnEntityTypeAdded(InternalEntityTypeBuilder entityTypeBuilder)
   at Microsoft.EntityFrameworkCore.Metadata.Internal.Model.AddEntityType(EntityType entityType)
   at Microsoft.EntityFrameworkCore.Metadata.Internal.Model.AddEntityType(Type type, ConfigurationSource configurationSource)
   at Microsoft.EntityFrameworkCore.Metadata.Internal.InternalModelBuilder.Entity(TypeIdentity type, ConfigurationSource configurationSource)
   at Microsoft.EntityFrameworkCore.Metadata.Internal.InternalModelBuilder.Entity(Type type, ConfigurationSource configurationSource)
   at Microsoft.EntityFrameworkCore.ModelBuilder.Entity(Type type)
   at Microsoft.EntityFrameworkCore.Infrastructure.ModelCustomizer.FindSets(ModelBuilder modelBuilder, DbContext context)
   at Microsoft.EntityFrameworkCore.Infrastructure.RelationalModelCustomizer.FindSets(ModelBuilder modelBuilder, DbContext context)
   at Microsoft.EntityFrameworkCore.Infrastructure.ModelCustomizer.Customize(ModelBuilder modelBuilder, DbContext context)
   at Microsoft.EntityFrameworkCore.Infrastructure.RelationalModelCustomizer.Customize(ModelBuilder modelBuilder, DbContext context)
   at Microsoft.EntityFrameworkCore.Infrastructure.ModelSource.CreateModel(DbContext context, IConventionSetBuilder conventionSetBuilder, IModelValidator validator)
   at Microsoft.EntityFrameworkCore.Infrastructure.ModelSource.<>c__DisplayClass5_0.<GetModel>b__0(Object k)
   at System.Collections.Concurrent.ConcurrentDictionary`2.GetOrAdd(TKey key, Func`2 valueFactory)
   at Microsoft.EntityFrameworkCore.Infrastructure.ModelSource.GetModel(DbContext context, IConventionSetBuilder conventionSetBuilder, IModelValidator validator)
   at Microsoft.EntityFrameworkCore.Internal.DbContextServices.CreateModel()
   at Microsoft.EntityFrameworkCore.Internal.DbContextServices.get_Model()
   at Microsoft.EntityFrameworkCore.Infrastructure.EntityFrameworkServicesBuilder.<>c.<TryAddCoreServices>b__7_1(IServiceProvider p)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitFactory(FactoryCallSite factoryCallSite, ServiceProvider provider)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor`2.VisitCallSite(IServiceCallSite callSite, TArgument argument)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitScoped(ScopedCallSite scopedCallSite, ServiceProvider provider)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor`2.VisitCallSite(IServiceCallSite callSite, TArgument argument)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitConstructor(ConstructorCallSite constructorCallSite, ServiceProvider provider)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor`2.VisitCallSite(IServiceCallSite callSite, TArgument argument)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitScoped(ScopedCallSite scopedCallSite, ServiceProvider provider)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor`2.VisitCallSite(IServiceCallSite callSite, TArgument argument)
   at Microsoft.Extensions.DependencyInjection.ServiceProvider.<>c__DisplayClass22_0.<RealizeService>b__0(ServiceProvider provider)
   at Microsoft.Extensions.DependencyInjection.ServiceProvider.GetService(Type serviceType)
   at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService(IServiceProvider provider, Type serviceType)
   at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService[T](IServiceProvider provider)
   at Microsoft.EntityFrameworkCore.DbContext.get_DbContextDependencies()
   at Microsoft.EntityFrameworkCore.DbContext.get_InternalServiceProvider()
   at Microsoft.EntityFrameworkCore.DbContext.get_DbContextDependencies()
   at Microsoft.EntityFrameworkCore.DbContext.get_Model()
   at Microsoft.EntityFrameworkCore.Internal.InternalDbSet`1.get_EntityType()
   at Microsoft.EntityFrameworkCore.Internal.InternalDbSet`1.get_EntityQueryable()
   at Microsoft.EntityFrameworkCore.Internal.InternalDbSet`1.System.Linq.IQueryable.get_Provider()
   at System.Linq.Queryable.Where[TSource](IQueryable`1 source, Expression`1 predicate)
   at TradeEvo.Chat.Controllers.HomeController.<ChatAsync>d__15.MoveNext() in myproj

        private readonly UserManager<ApplicationUser> _userManager;
        private readonly SignInManager<ApplicationUser> _signInManager;
        private readonly ILogger _logger;
        private readonly TradeEvoDbContext _context;
        public HomeController(
            UserManager<ApplicationUser> userManager,
            SignInManager<ApplicationUser> signInManager,
            ILogger<HomeController> logger,
            TradeEvoDbContext context)
        {
            _userManager = userManager;
            _signInManager = signInManager;
            _logger = logger;
            _context = context;
        }

<PackageReference Include="Microsoft.AspNetCore.All" Version="2.0.6" />
    <PackageReference Include="Microsoft.AspNetCore.Identity" Version="2.0.2" />
    <PackageReference Include="Microsoft.AspNetCore.Identity.EntityFrameworkCore" Version="2.0.2" />
    <PackageReference Include="Microsoft.AspNetCore.Owin" Version="2.0.2" />
    <PackageReference Include="Microsoft.AspNetCore.SignalR" Version="1.0.0-preview2-final" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="2.0.2" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="2.0.2" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="2.0.2" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.Tools.DotNet" Version="2.0.0" />
    <PackageReference Include="Microsoft.VisualStudio.Web.CodeGeneration.Design" Version="2.0.3" />
    <PackageReference Include="Npgsql.EntityFrameworkCore.PostgreSQL" Version="2.0.1" />