How can I get valueprovider in asp.net core 1.0?

In MVC5, I will get value provider in action of controller like this:

public class ConfigurationsController : Controller
{
    public ActionResult Index()
    {
        var valueProvider = this.ValueProvider;
        var someValue = valueProvider.GetValue("someKey");
    }
}

But now It's gone in asp.net core 1.0. Please help me how to get the value provider in new version?

Thank you,