问题
I am trying to scaffold and getting following error:
There was an error running the selected code generator Method not found: 'Void EntityFrameworkCore.Design.Internal.DbContextOperations
回答1:
https://docs.microsoft.com/en-us/ef/core/get-started/aspnetcore/existing-db?view=aspnetcore-2.0#install-entity-framework
I suspect you are missing the assemblies that are necessary for scaffolding? I also assume you are trying to reverse engineer an existing db?
example
Scaffold-DbContext "Server=(localdb)\mssqllocaldb;Database=Blogging;Trusted_Connection=True;" Microsoft.EntityFrameworkCore.SqlServer -OutputDir Models
if it fails like i can't find it might be a pmc issue, try closing down VS try again. After that its probably a configuration with missing assemblies.
回答2:
I got this error too when trying to add a new controller. The day before I had upgraded both Microsoft.EntityFrameworkCore.SqlServer and Microsoft.EntityFrameworkCore.Tools Nuget Packages from version 2.0.2 to 2.1.3.
Downgrading both packages to 2.0.2 allowed me to scaffold a new controller again.
回答3:
It may be the Microsoft.EntityFrameworkCore.Design version issue. Uust update it to version 2.0.3. It worked for me.
回答4:
Saeef's error is from trying to create CRUD razor pages, not creating the domain classes from an existing database
回答5:
I had the same problem. I had two instances of VS2017 (enterprise & developer edition) for some reason I updated only one of them. The shourtcut on my desk was the 'out of date version' so I didnt figure it out until now. I uninstalled the older, updated the other to 15.8+ and it works fine now.
来源：https://stackoverflow.com/questions/50645265/method-not-found-void-entityframeworkcore-design-internal-dbcontextoperations