Can ASP.NET MVC + EF scaffolding be used after implementing EntityTypeConfiguration classes?

Question

Background

Visual Studio scaffolding for new ASP.NET MVC Controllers bound to Entity Framework work well when the models use data annotations or the direct lines within OnModelCreating(DbModelBuilder) to describe their characteristics.

Issue

However, in our scenario, the content of OnModelCreating is refactored using individual EntityTypeConfiguration<T> classes. When attempting to create a new Controller via the MVC+EF scaffolding the following pop up error occurs:

There was an error running the selected code generator: 'A configuration for type SomeModelClass has already been added. To reference the existing configuration use the Entity<T>() or ComplexType<T>() methods.'

Is there a fix (ex. custom code or project configuration)?

Answer 1

Here is something that seems to be the same issue as yours : Scaffolding controller doesn't work with visual studio 2013 update 3 and 4

This is a soluton that seems to work :

I had added some custom configuration for one of my Model classes to add a relationship using the fluent API. This was specified in my dbContext class in the OnModelCreating override using the following:

modelBuilder.Configurations.Add(new OrderConfiguration()); Commenting out the above line allowed the Controller scaffolding to run as expected.

VS 2013 update 2 had a problem with this and the scaffolding came up with an unhelpful error with no further information. In installed Update 3 and it gave just enough detail to track down the underlying issue.