从 EF 5 升级到 EF 6.0.2 后出错

Question

从 EF 5 升级到 EF 6.0.2 后，从 Package Manager Console 执行 Update-Database 命令时出现此错误：

无法加载文件或程序集'System.Web.Helpers，版本=3.0.0.0， Culture=neutral, PublicKeyToken=31bf3856ad364e35' 或其之一 依赖关系。系统找不到指定的文件。

升级前一切正常。

这是我的app.config：

    <configSections>
    <section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
    <!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 -->
  </configSections>
  <connectionStrings>
    <add name="DefaultConnection" connectionString="Data Source=.;Initial Catalog=aspnet-CodeFirst-Test;Integrated Security=SSPI;" providerName="System.Data.SqlClient" />
  </connectionStrings>
  <system.web>
    <roleManager enabled="true" defaultProvider="SimpleRoleProvider">
      <providers>
        <clear />
        <add name="SimpleRoleProvider" type="WebMatrix.WebData.SimpleRoleProvider, WebMatrix.WebData" />
      </providers>
    </roleManager>
    <membership defaultProvider="SimpleMembershipProvider">
      <providers>
        <clear />
        <add name="SimpleMembershipProvider" type="WebMatrix.WebData.SimpleMembershipProvider, WebMatrix.WebData" />
      </providers>
    </membership>
  </system.web>
  <runtime>
    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
      <qualifyAssembly partialName="WebMatrix.WebData" fullName="WebMatrix.WebData, Version=2.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" />
    </assemblyBinding>
  </runtime>
  <entityFramework>
    <defaultConnectionFactory type="System.Data.Entity.Infrastructure.LocalDbConnectionFactory, EntityFramework">
      <parameters>
        <parameter value="v11.0" />
      </parameters>
    </defaultConnectionFactory>
    <providers>
      <provider invariantName="System.Data.SqlClient" type="System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer" />
    </providers>
  </entityFramework>
  <startup>
    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5.1" />
  </startup>

这是我的Configuration.cs 文件：

public Configuration()
    {
        Database.SetInitializer<DataContext>(new DropCreateDatabaseAlways<DataContext>());
        AutomaticMigrationsEnabled = true;
        AutomaticMigrationDataLossAllowed = true;
    }

    protected override void Seed(DataContext context)
    {
        //  This method will be called after migrating to the latest version.

        //  You can use the DbSet<T>.AddOrUpdate() helper extension method 
        //  to avoid creating duplicate seed data. E.g.
        //
        //    context.People.AddOrUpdate(
        //      p => p.FullName,
        //      new Person { FullName = "Andrew Peters" },
        //      new Person { FullName = "Brice Lambson" },
        //      new Person { FullName = "Rowan Miller" }
        //    );
        //

        SeedMembership(context);
    }

我读到SimpleMembershipProvider 被Identity '替换'。不确定这是否与此错误有关。但如果有人知道如何进行迁移的教程，我很想有一个链接。

数据库层也是一个class lib 项目。里面没有安装MVC。

Answer 1

尝试将此添加到您的 web.config 下的运行时部分：

<runtime>
    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
      <dependentAssembly>
        <assemblyIdentity name="System.Web.Helpers" publicKeyToken="31bf3856ad364e35" />
        <bindingRedirect oldVersion="1.0.0.0-3.0.0.0" newVersion="3.0.0.0" />
      </dependentAssembly>

您的项目也应该引用 System.Web.Helpers