命名空间 'microsoft.web' 中不存在类型或命名空间名称 'web pages'

Question

我因上述错误而卡在我的项目中。我已经多次尝试 copy local=true 和 <private>true</private>，但它并没有解决我的问题。我还有其他像这样的错误，它们是：

The type or namespace name 'Transcations' does not exist in the namespace 'system'

the type or namespace name 'web matrix' does not exist in the namespace 'system'

the type or namespace name 'optimization' does not exist in the namespace 'system.web'

Error   18  The type or namespace name 'IMigrationMetadata' could not be found (are you missing a using directive or an assembly reference?)

Error   23  The type or namespace name 'HttpConfiguration' could not be found (are you missing a using directive or an assembly reference?)

Error   2   The type or namespace name 'Entity' does not exist in the namespace 'System.Data' (are you missing an assembly reference?)

Error   3   The type or namespace name 'Entity' does not exist in the namespace 'System.Data' (are you missing an assembly reference?)  

Error   4   The type or namespace name 'Entity' does not exist in the namespace 'System.Data' (are you missing an assembly reference?)

Error   6   The type or namespace name 'Entity' does not exist in the namespace 'System.Data' (are you missing an assembly reference?)

还有更多....

我有所有的 nuget 包。请帮助我。

Answer 1

如果您查看 Visual Studio 中的 documentation, the System.Data.Entity namespace is contained in the EntityFramework.dll assembly. Open the Package Manager 和 运行 此命令以通过 NuGet 安装它。

Install-Package EntityFramework