我试图创建一个新的迁移,但我得到一个System.ArgumentNullException
他说：
他说：
System.ArgumentNullException: Value cannot be null.
Parameter name: language
at Microsoft.EntityFrameworkCore.Utilities.Check.NotNull[T](T value,String parameterName)
at Microsoft.EntityFrameworkCore.Design.Internal.MigrationsOperations..ctor
(IOperationReporter reporter,Assembly assembly,Assembly
startupAssembly,String projectDir,String rootNamespace,String
language)
at Microsoft.EntityFrameworkCore.Design.OperationExecutor.<>c__DisplayClass4_0.<.ct
or>b__4()
at Microsoft.EntityFrameworkCore.Internal.LazyRef`1.get_Value()
at Microsoft.EntityFrameworkCore.Design.OperationExecutor.AddMigrationImpl(String name,String outputDir,String contextType)
at Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.<>c__DisplayClass3_0`1.<Execute>b__0()
at Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.Execute(Action action)
Value cannot be null.
Parameter name: language
解决方法
它与EF Core而不是EF6有关,看起来2.1.0.preview1-final版本中存在一个错误.
- Check the version you are running with dotnet ef –version
- Downgrade to the Microsoft.EntityFrameworkCore.Design 2.0.1 version.
