我最近使用Entity Framework 5开发了一个.net 4.5库.一切正常,直到我被告知我必须降级到.net 4.0才能与
Windows 2003保持兼容.
我使用程序包管理器控制台卸载了EF 5并获得了成功的消息,然后这个消息：
Failed to generate binding redirects for 'MyProjectName'. An item with the same key has already been added.
降级和安装Entity Framework后会出现相同的消息.
一切都在编译.但是在执行时我有这个例外：
The type initializer for 'System.Data.Entity.Internal.AppConfig' threw an exception. Could not load file or assembly 'EntityFramework,Version=5.0.0.0,Culture=neutral,PublicKeyToken=b77a5c561934e089' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)":"EntityFramework,PublicKeyToken=b77a5c561934e089"
在Web.Config(以及库的App.Config)中,我有以下几行：
<section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection,EntityFramework,PublicKeyToken=b77a5c561934e089" requirePermission="false"/>
...
<runtime>
<assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
<dependentAssembly>
<assemblyIdentity name="EntityFramework" publicKeyToken="b77a5c561934e089"
culture="neutral" />
<bindingRedirect oldVersion="0.0.0.0-5.0.0.0" newVersion="5.0.0.0" />
</dependentAssembly>
</assemblyBinding>
</runtime>
任何帮助,将不胜感激.
解决方法
由于另一个话题,我终于解决了这个问题：
could-not-load-file-or-assembly-entityframework-after-downgrading-ef-5-0-0-0
尽管我使用Package Manager Console安装了EF 5软件包. .Net 4.0的实体框架的实际版本是4.4版.我已经改变了配置文件中的值,它确实有效！
<section name="entityFramework"
type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection,Version=4.4.0.0,PublicKeyToken=b77a5c561934e089" requirePermission="false"/>
...
<dependentAssembly>
<assemblyIdentity name="EntityFramework" publicKeyToken="b77a5c561934e089"
culture="neutral"/>
<bindingRedirect oldVersion="0.0.0.0-4.4.0.0" newVersion="4.4.0.0"/>
</dependentAssembly>
