Inject DbContext with Autofac

Question

I have the following EntityFramework context:

public class Context : DbContext, IDbContext {
}

Where IDbContext is the following:

public interface IDbContext {
  DbEntityEntry Entry(Object entity);
  IEnumerable<DbEntityValidationResult> GetValidationErrors();
  Int32 SaveChanges();
  Task<Int32> SaveChangesAsync();
  Task<Int32> SaveChangesAsync(CancellationToken cancellationToken);
  DbSet Set(Type entityType);
  DbSet<TEntity> Set<TEntity>() where TEntity : class;
} // IDbContext

What is the correct way to configure DbContext injection with Autofac?

With StructureMap I had the following:

For<IDbContext>().Use(x => new Context());

score 17 · Accepted Answer · answered Apr 10 '15 at 12:05

17

Many ways, depending on scope you need, conventions etc.

Example:

containerBuilder
  .RegisterType<Context>()
  .AsImplementedInterfaces()
  .InstancePerLifetimeScope();

answered Apr 10 '15 at 12:05

Jacek Gorgoń

3,206
1
26
43

1

Gorgon: Is there a reason for using AsImplementedInterfaces() instead of specifying the interface, eg., As? And why not use InstancePerRequest()?Thank You. – Miguel Moura Apr 10 '15 at 12:16
6

Specifying interface(s) explicitly is fine. It's a matter of taste, conventions, discipline, etc (I prefer automagical stuff with conventions). InstancePerRequest() is fine if you're strictly in a web context, but won't work otherwise. InstancePerLifetimeScope() assumes you're aware of the scope and control it by some means yourself (e.g. create one per thread in a batch job). – Jacek Gorgoń Apr 10 '15 at 12:57

score 0 · Answer 2 · answered Dec 01 '21 at 08:39

Assuming that your constructor expects to receive a DbContext factory Func<IDbContext> so you'll be able to get new instances of DbContext on each call and dispose them on your own, you should use:

builder.RegisterType<Context>().AsImplementedInterfaces().InstancePerDependency().ExternallyOwned();

You might want to take a look at https://autofac.readthedocs.io/en/latest/resolve/relationships.html

Inject DbContext with Autofac

2 Answers2

Linked