VS2017 中的 JetEntityFrameworkProvider 设置

问题描述

在 VS2017 15.9.21 for .NET 4.5 中编译我的项目后，出现以下错误，我错过了什么？

Unable to determine the provider name for provider factory of type 'JetEntityFrameworkProvider.JetProviderFactory'. Make sure that the ADO.NET provider is installed or registered in the application config.

Error Dialog

这是抛出异常的地方：

JetConnection.ShowsqlStatements = True

Dim fac1 = New JetConnectionFactory()
Dim con1 = fac1.CreateConnection(ORMGlobal.ConnectionString)

Using db As ORM = New ORM(con1)
    Dim model = db.People.Count()
    ' ...
End Using

这是我的 DbContext 设置：

Partial Public Class ORM
    Inherits DbContext

    Public Sub New()
        MyBase.New()
        Database.Setinitializer(New NullDatabaseInitializer(Of ORM))
    End Sub

    Public Sub New(con As Common.DbConnection)
        MyBase.New(con,True)
        Database.Setinitializer(New NullDatabaseInitializer(Of ORM))
    End Sub

    ' ...
End Class

这是我的config.app

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <entityFramework>
    <providers>
      <provider invariantName="JetEntityFrameworkProvider" type="JetEntityFrameworkProvider.JetProviderServices,JetEntityFrameworkProvider" />
      <provider invariantName="System.Data.sqlClient" type="System.Data.Entity.sqlServer.sqlProviderServices,EntityFramework.sqlServer"/>
    </providers>
  </entityFramework>
  <system.data>
    <DbProviderFactories>
      <remove invariant="JetEntityFrameworkProvider"/>
      <add invariant="JetEntityFrameworkProvider" name="Jet Entity Framework Provider" description="Jet Entity Framework Provider"
        type="JetEntityFrameworkProvider.JetProviderFactory,JetEntityFrameworkProvider"/>
    </DbProviderFactories>
  </system.data>
</configuration>

异常详情：

Exception thrown: 'System.NotSupportedException' in EntityFramework.dll
5/20/2021 3:49:07 PM :dwl: :LV:: Error in ConnectToDSN: System.NotSupportedException: Unable to determine the provider name for provider factory of type 'JetEntityFrameworkProvider.JetProviderFactory'. Make sure that the ADO.NET provider is installed or registered in the application config.
   at System.Data.Entity.Utilities.DbProviderFactoryExtensions.GetProviderInvariantName(DbProviderFactory factory)
   at System.Data.Entity.Infrastructure.DependencyResolution.DefaultInvariantNameResolver.GetService(Type type,Object key)
   at System.Data.Entity.Infrastructure.DependencyResolution.CachingDependencyResolver.<>c__displayClass4_0.<GetService>b__0(Tuple`2 k)
   at System.Collections.Concurrent.ConcurrentDictionary`2.GetorAdd(TKey key,Func`2 valueFactory)
   at System.Data.Entity.Infrastructure.DependencyResolution.CachingDependencyResolver.GetService(Type type,Object key)
   at System.Data.Entity.Infrastructure.DependencyResolution.ResolverChain.<>c__displayClass5_0.<GetService>b__0(IDbDependencyResolver r)
   at System.Linq.Enumerable.WhereSelectArrayIterator`2.MoveNext()
   at System.Linq.Enumerable.FirstOrDefault[TSource](IEnumerable`1 source,Func`2 predicate)
   at System.Data.Entity.Infrastructure.DependencyResolution.ResolverChain.GetService(Type type,Object key)
   at System.Data.Entity.Infrastructure.DependencyResolution.RootDependencyResolver.GetService(Type type,Object key)
   at System.Data.Entity.Infrastructure.DependencyResolution.CompositeResolver`2.GetService(Type type,Object key)
   at System.Data.Entity.Infrastructure.DependencyResolution.DbDependencyResolverExtensions.GetService[T](IDbDependencyResolver resolver,Object key)
   at System.Data.Entity.Utilities.DbConnectionExtensions.GetProviderInvariantName(DbConnection connection)
   at System.Data.Entity.Internal.InternalConnection.get_ProviderName()
   at System.Data.Entity.Internal.LazyInternalContext.get_ProviderName()
   at System.Data.Entity.Internal.DefaultModelCacheKeyFactory.Create(DbContext context)
   at System.Data.Entity.Internal.LazyInternalContext.InitializeContext()
   at System.Data.Entity.Internal.InternalContext.Initialize()
   at System.Data.Entity.Internal.InternalContext.GetEntitySetAndBaseTypeForType(Type entityType)
   at System.Data.Entity.Internal.Linq.InternalSet`1.Initialize()
   at System.Data.Entity.Internal.Linq.InternalSet`1.get_InternalContext()
   at System.Data.Entity.Infrastructure.DbQuery`1.System.Linq.IQueryable.get_Provider()
   at System.Linq.Queryable.Count[TSource](IQueryable`1 source)
   at TheBoardRoom.LockView.sqldbHandler.ConnectToDSN(String sConnDSN,ADOConnection& connDB)

解决方法

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