.net-4.0 - 为什么在新的 MVC4 项目中会出现编译错误？

Question

我一直无法找到答案，整个周末都在网上搜索，所以我希望你能帮我解决这个问题。

使用 Visual Studio 2012 时，我创建了一个新的 MVC4 Web 应用程序项目并遇到一些编译错误。

这是我的问题:

我使用 Visual Studio 2012 创建了一个新的 MVC4 Web 应用程序，我选择了 Internet 应用程序并将其设置为使用 RAZOR 引擎。

我转到应用程序属性并在应用程序选项卡下将目标框架从 .NET Framework 4.5 更改为 .NET Framework 4。

构建产生以下错误:

Error 1 The type name 'TableAttribute' could not be found. This type has been forwarded to assembly 'System.ComponentModel.DataAnnotations, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35'. Consider adding a reference to that assembly. c:\users\saad\documents\visual studio 2012\Projects\MvcApplication1\MvcApplication1\Models\AccountModels.cs 21 6 MvcApplication1

Error 2 The type or namespace name 'Table' could not be found (are you missing a using directive or an assembly reference?) c:\users\saad\documents\visual studio 2012\Projects\MvcApplication1\MvcApplication1\Models\AccountModels.cs 21 6 MvcApplication1

Error 3 The type or namespace name 'DatabaseGeneratedAttributeAttribute' could not be found (are you missing a using directive or an assembly reference?) c:\users\saad\documents\visual studio 2012\Projects\MvcApplication1\MvcApplication1\Models\AccountModels.cs 25 10 MvcApplication1

Error 4 The type name 'DatabaseGeneratedAttribute' could not be found. This type has been forwarded to assembly 'System.ComponentModel.DataAnnotations, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35'. Consider adding a reference to that assembly. c:\users\saad\documents\visual studio 2012\Projects\MvcApplication1\MvcApplication1\Models\AccountModels.cs 25 10 MvcApplication1

Error 5 The type or namespace name 'CompareAttribute' could not be found (are you missing a using directive or an assembly reference?) c:\users\saad\documents\visual studio 2012\Projects\MvcApplication1\MvcApplication1\Models\AccountModels.cs 54 10 MvcApplication1

Error 6 The type or namespace name 'Compare' could not be found (are you missing a using directive or an assembly reference?) c:\users\saad\documents\visual studio 2012\Projects\MvcApplication1\MvcApplication1\Models\AccountModels.cs 54 10 MvcApplication1

Error 7 The type or namespace name 'CompareAttribute' could not be found (are you missing a using directive or an assembly reference?) c:\users\saad\documents\visual studio 2012\Projects\MvcApplication1\MvcApplication1\Models\AccountModels.cs 87 10 MvcApplication1

Error 8 The type or namespace name 'Compare' could not be found (are you missing a using directive or an assembly reference?) c:\users\saad\documents\visual studio 2012\Projects\MvcApplication1\MvcApplication1\Models\AccountModels.cs 87 10 MvcApplication1

Answer 1

只需重新安装 EntityFramework:

转到包管理器控制台

卸载包 entityframework

安装包 Entity Framework

这就是错误应该消失!