How to use a Service Factory in ASP.net Core

AspDotNetCoreServiceFactory.cs

// Startup.cs
public void ConfigureServices(IServiceCollection services)
{
  services.AddTransient<Func<key, IRepository<model>>>(serviceProvider => key =>
  {
      var repositoryServiceFactory = new RepositoryServiceFactory();
      return repositoryServiceFactory.Build(key, Configuration);
  });
 }
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// In the controller
public MyController(Func<key, IRepository<model>> repository)
{
    _repository = repository("ModelA");
}