Azure WebSites或Azure云服务上的MVC4 API [错误]:'System.ComponentModel.DataAnnotations.Schema.DatabaseGeneratedOption'

Question

当我尝试将我的Web API项目部署到Azure上的Cloud WebSites和Cloud Hosted Services时,我收到此错误:

"{"ExceptionType":"System.TypeLoadException","Message":"Could not load type 'System.ComponentModel.DataAnnotations.Schema.DatabaseGeneratedOption' from assembly 'System.ComponentModel.DataAnnotations, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35'.","StackTrace":"\r\nServer stack trace: \r\n   at System.Reflection.RuntimeAssembly.GetExportedTypes(RuntimeAssembly assembly, ObjectHandleOnStack retTypes)\r\n   at System.Reflection.RuntimeAssembly.GetExportedTypes()\r\n   at System.Web.Http.Dispatcher.DefaultHttpControllerTypeResolver.GetControllerTypes(IAssembliesResolver assembliesResolver)\r\n   at System.Web.Http.WebHost.WebHostHttpControllerTypeResolver.GetControllerTypes(IAssembliesResolver assembliesResolver)\r\n   at System.Web.Http.Dispatcher.HttpControllerTypeCache.InitializeCache()\r\n   at System.Lazy`1.CreateValue()\r\n\r\nException rethrown at [0]: \r\n   at System.Reflection.RuntimeAssembly.GetExportedTypes(RuntimeAssembly assembly, ObjectHandleOnStack retTypes)\r\n   at System.Reflection.RuntimeAssembly.GetExportedTypes()\r\n   at System.Web.Http.Dispatcher.DefaultHttpControllerTypeResolver.GetControllerTypes(IAssembliesResolver assembliesResolver)\r\n   at System.Web.Http.WebHost.WebHostHttpControllerTypeResolver.GetControllerTypes(IAssembliesResolver assembliesResolver)\r\n   at System.Web.Http.Dispatcher.HttpControllerTypeCache.InitializeCache()\r\n   at System.Lazy`1.CreateValue()\r\n   at System.Lazy`1.LazyInitValue()\r\n   at System.Web.Http.Dispatcher.DefaultHttpControllerSelector.InitializeControllerInfoCache()\r\n   at System.Lazy`1.CreateValue()\r\n\r\nException rethrown at [1]: \r\n   at System.Web.Http.Dispatcher.DefaultHttpControllerSelector.SelectController(HttpRequestMessage request)\r\n   at System.Web.Http.Dispatcher.HttpControllerDispatcher.SendAsyncInternal(HttpRequestMessage request, CancellationToken cancellationToken)\r\n   at System.Web.Http.Dispatcher.HttpControllerDispatcher.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)"}"

这里只是消息:

"Could not load type 'System.ComponentModel.DataAnnotations.Schema.DatabaseGeneratedOption' from assembly 'System.ComponentModel.DataAnnotations, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35'."

当我尝试从远程站点点击任何API时,就会发生这种情况.我知道它不是我的500错误,因为我的一些API不会抛出它们而不管发生了什么.

有一点需要注意,我不确定这是否会影响任何东西是我开始这个针对.NET 4.5的项目,但后来当Azure网站表示他们不支持4.5时将其切换到4.0.

除了这个链接,我找不到任何关于此的信息:http: //support.appharbor.com/discussions/problems/4822-internal-server-error-500-mvc-4-web-api

除了那家伙正在使用app-harbour,andeven仍然没有解决方案.谢谢你的帮助.

Answer 1

你是正确的开始在.NET 4.5和回滚导致问题,这是有关此问题和链接的官方文档.

将ASP.NET MVC 4项目从4.5更改为目标4.0不会更新EntityFramework程序集引用:如果在目标4.5之后将ASP.NET MVC 4项目更改为目标4.0,则对EntityFramwork程序集的引用仍将指向4.5版本.要解决此问题,请重新安装EntityFramework NuGet包.

将项目切换到.NET 4.0后重新安装EntityFramework就可以了.

参考:http://www.asp.net/whitepapers/mvc4-release-notes#_Toc303253815

当我在.NET 4.0中编译MVC RC项目并尝试在没有安装Visual Studio 2012 RC的服务器上的IIS中托管它时,这种情况发生在我身上.

(注意:在服务器上安装Visual Studio 2012 RC也解决了问题,但为了向后兼容,上述修复要好得多.)

Answer 2

所以看来问题是由我从 4.5 回滚到 .NET 4 而实体没有回滚引起的。实体 5 似乎只在 .NET 4.5 上运行，当部署期望 4.3.1 时，它有一个 5.0.0 DLL，它把一切搞乱了。