如何创建autofac工厂以解决依赖关系

我正在使用IDbcontext访问我的数据库

   public sealed class DbContext : IDbContext
{
    private bool disposed;
    private SqlConnection connection;
    public DbContext(string connectionString)
    {
        connection = new SqlConnection(connectionString);
    }
    public IDbConnection Connection
    {
        get
        {
            if (disposed) throw new ObjectDisposedException(GetType().Name);
            return connection;
        }
    }
    public IDbTransaction CreateOpenedTransaction()
    {
        if (connection.State != ConnectionState.Open)
            Connection.Open();
        return Connection.BeginTransaction();
    }
    public IEnumerable<T> ExecuteProcedure<T>(string procedure, dynamic param = null, IDbTransaction transaction = null)
    {
        if (connection.State == ConnectionState.Closed)
        {
            connection.Open();
        }
        return Dapper.SqlMapper.Query<T>(connection, procedure, param, transaction,
            commandType: CommandType.StoredProcedure);
    }
    public int ExecuteProcedure(string procedure, dynamic param = null, IDbTransaction transaction = null)
    {
        if (connection.State == ConnectionState.Closed)
        {
            connection.Open();
        }
        return Dapper.SqlMapper.Execute(connection, procedure, param, transaction,
            commandType: CommandType.StoredProcedure);
    }
    public void Dispose()
    {
        Debug.WriteLine("** Disposing DbContext");
        if (disposed) return;
        if (connection != null)
        {
            connection.Dispose();
            connection = null;
        }
        disposed = true;
    }
}

我有两个数据库"第一个"answers"第二个"

在解决拳头的问题时，我使用

 builder.Register<IDbContext>(c =>
          new DbContext(ConfigurationManager.ConnectionStrings["first"].ConnectionString))
          .InstancePerDependency();

所以我需要添加：

builder.Register<IDbContext>(c =>
              new DbContext(ConfigurationManager.ConnectionStrings["second"].ConnectionString))
          .InstancePerDependency();

我需要为Dbcontext创建一个工厂，并使用带有autofac的NamedResolve，我该怎么做？？

public class DbContextFactory
{
    private ILifetimeScope m_RootLifetimeScope;
    public DbContextFactory(ILifetimeScope rootLifetimeScope)
    {
        m_RootLifetimeScope = rootLifetimeScope;
    }
    public IDbContext CreateDbContext()
    {
        if (logic for selection first dbcontext)
        {
            return m_RootLifetimeScope.ResolveNamed<IDbContext>("first");
        }
        else if (logic for selection second dbcontext)
        {
            return m_RootLifetimeScope.ResolveNamed<IDbContext>("second");
        }
        else 
        {
            throw new NotSupportedException();
        }
    }
}
//registration
builder.RegisterType<DbContextFactory>().SingleInstance();
//using
var factory = yourContainer.Resolve<DbContextFactory>();
var context = factory.CreateDbContext();