异常在EF使用代码首先

Question

“发生错误创建 的EntityFramework配置节处理程序：对的DbContext类型 配置‘BookLibrary.Data.LibraryContext，BookLibrary’被在应用配置中指定了多个 倍每个上下文。只能配置一次 “。

这是我的上下文文件：

public class LibraryContext : IdentityDbContext<ApplicationUser> 
    { 
     /// <summary> 
     /// Gets or sets the context books 
     /// </summary> 
     public DbSet<Book> Books { get; set; } 

     /// <summary> 
     /// Gets or sets the context authors 
     /// </summary> 
     public DbSet<Author> Authors { get; set; } 

     /// <summary> 
     /// Gets or sets the context categories. 
     /// </summary> 
     public DbSet<Category> Categories { get; set; } 

     /// <summary> 
     /// Gets or sets the context transactions 
     /// </summary> 
     public DbSet<Transaction> Transactions { get; set; } 

     /// <summary> 
     /// Creates a new instance of the <see cref="LibraryContext"/> class. 
     /// </summary> 
     public LibraryContext() 
      : base("DefaultConnection") 
     { 
     } 

     /// <summary> 
     /// Factory method to create a new instance of the <see cref="LibraryContext"/> class. 
     /// </summary> 
     /// <returns>Instance</returns> 
     public static LibraryContext Create() 
     { 
      return new LibraryContext(); 
     } 
} 

Answer 1

这是我的Web.config文件：

---

<configuration> 
    <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=MYHAZBO-PC\SQLEXPRESS;Initial Catalog=BookingLibrary;Integrated Security=true;User ID=sa;password=Myhazbo; MultipleActiveResultSets=true" providerName="System.Data.SqlClient" /> 
    </connectionStrings> 
    <appSettings> 
    <add key="webpages:Version" value="3.0.0.0" /> 
    <add key="webpages:Enabled" value="false" /> 
    <add key="ClientValidationEnabled" value="true" /> 
    <add key="UnobtrusiveJavaScriptEnabled" value="true" /> 
    </appSettings> 
    <system.web> 
    <authentication mode="None" /> 
    <compilation debug="true" targetFramework="4.5" /> 
    <httpRuntime targetFramework="4.5" /> 
    </system.web> 
    <system.webServer> 
    <modules> 
     <remove name="FormsAuthentication" /> 
    </modules> 
    <handlers> 
     <remove name="ExtensionlessUrlHandler-Integrated-4.0" /> 
     <remove name="OPTIONSVerbHandler" /> 
     <remove name="TRACEVerbHandler" /> 
     <add name="ExtensionlessUrlHandler-Integrated-4.0" path="*." verb="*" type="System.Web.Handlers.TransferRequestHandler" preCondition="integratedMode,runtimeVersionv4.0" /> 
    </handlers> 
    </system.webServer> 
    <runtime> 
    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1"> 
     <dependentAssembly> 
     <assemblyIdentity name="Microsoft.Owin" publicKeyToken="31bf3856ad364e35" /> 
     <bindingRedirect oldVersion="0.0.0.0-3.0.0.0" newVersion="3.0.0.0" /> 
     </dependentAssembly> 
     <dependentAssembly> 
     <assemblyIdentity name="Microsoft.Owin.Security.OAuth" publicKeyToken="31bf3856ad364e35" /> 
     <bindingRedirect oldVersion="0.0.0.0-3.0.0.0" newVersion="3.0.0.0" /> 
     </dependentAssembly> 
     <dependentAssembly> 
     <assemblyIdentity name="Microsoft.Owin.Security.Cookies" publicKeyToken="31bf3856ad364e35" /> 
     <bindingRedirect oldVersion="0.0.0.0-3.0.0.0" newVersion="3.0.0.0" /> 
     </dependentAssembly> 
     <dependentAssembly> 
     <assemblyIdentity name="Microsoft.Owin.Security" publicKeyToken="31bf3856ad364e35" /> 
     <bindingRedirect oldVersion="0.0.0.0-3.0.0.0" newVersion="3.0.0.0" /> 
     </dependentAssembly> 
     <dependentAssembly> 
     <assemblyIdentity name="Newtonsoft.Json" culture="neutral" publicKeyToken="30ad4fe6b2a6aeed" /> 
     <bindingRedirect oldVersion="0.0.0.0-6.0.0.0" newVersion="6.0.0.0" /> 
     </dependentAssembly> 
     <dependentAssembly> 
     <assemblyIdentity name="System.Web.Helpers" publicKeyToken="31bf3856ad364e35" /> 
     <bindingRedirect oldVersion="1.0.0.0-3.0.0.0" newVersion="3.0.0.0" /> 
     </dependentAssembly> 
     <dependentAssembly> 
     <assemblyIdentity name="System.Web.Mvc" publicKeyToken="31bf3856ad364e35" /> 
     <bindingRedirect oldVersion="1.0.0.0-5.2.2.0" newVersion="5.2.2.0" /> 
     </dependentAssembly> 
     <dependentAssembly> 
     <assemblyIdentity name="System.Web.Optimization" publicKeyToken="31bf3856ad364e35" /> 
     <bindingRedirect oldVersion="1.0.0.0-1.1.0.0" newVersion="1.1.0.0" /> 
     </dependentAssembly> 
     <dependentAssembly> 
     <assemblyIdentity name="System.Web.WebPages" publicKeyToken="31bf3856ad364e35" /> 
     <bindingRedirect oldVersion="1.0.0.0-3.0.0.0" newVersion="3.0.0.0" /> 
     </dependentAssembly> 
     <dependentAssembly> 
     <assemblyIdentity name="WebGrease" publicKeyToken="31bf3856ad364e35" /> 
     <bindingRedirect oldVersion="0.0.0.0-1.6.5135.21930" newVersion="1.6.5135.21930" /> 
     </dependentAssembly> 
     <dependentAssembly> 
     <assemblyIdentity name="Antlr3.Runtime" publicKeyToken="eb42632606e9261f" culture="neutral" /> 
     <bindingRedirect oldVersion="0.0.0.0-3.5.0.2" newVersion="3.5.0.2" /> 
     </dependentAssembly> 
    </assemblyBinding> 
    </runtime> 
    <entityFramework> 
    <contexts> 
     <context type="BookLibrary.Data.LibraryContext, BookLibrary"> 
     <databaseInitializer type="BookLibrary.Data.LibraryInitializer, BookLibrary" /> 
     </context> 
    </contexts> 
    <defaultConnectionFactory type="System.Data.Entity.Infrastructure.LocalDbConnectionFactory, EntityFramework"> 
     <parameters> 
     <parameter value="mssqllocaldb" /> 
     </parameters> 
    </defaultConnectionFactory> 
    <providers> 
     <provider invariantName="System.Data.SqlClient" type="System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer" /> 
    </providers> 
    </entityFramework> 
</configuration>