Excerpt from https://github.com/kirkshoop/rxaccelerometer showing how to create a ReactiveCommand and bind it to a Xaml button

gistfile1.cpp

typedef rxrt::EventPattern<Object^, Windows::UI::Xaml::RoutedEventArgs^> RoutedEventPattern;

// start out disabled
enabled = std::make_shared<rx::BehaviorSubject<bool>>(false);

// use enabled to control canExecute
disable = std::make_shared < rxrt::ReactiveCommand < RoutedEventPattern> >(observable(enabled));

from(observable(disable))
  // stay on the ui thread
  .subscribe([this](RoutedEventPattern)
  // on click
  {
    ...
    // now the scenario is disabled
    this->enabled->OnNext(false);
  });

rxrt::BindCommand(ScenarioDisableButton, disable);