didChangeAppLifecycleState method

@override void didChangeAppLifecycleState(AppLifecycleState state)

Called when the system puts the app in the background or returns the app to the foreground.

An example of implementing this method is provided in the class-level documentation for the WidgetsBindingObserver class.

This method exposes notifications from SystemChannels.lifecycle.

See also:

• AppLifecycleListener, an alternative API for responding to application lifecycle changes.

Implementation

@override
void didChangeAppLifecycleState(AppLifecycleState state) {
  super.didChangeAppLifecycleState(state);
  // print(state);
  if (_history.isEmpty) return;
  switch (state) {
    case AppLifecycleState.resumed: // active
      // Top route trigger active
      //
      // 最上面的route触发active
      _sendEventsToLastRoute(lifecycleEventsVisibleAndActive);
      if (_history.last.route is! PageRoute) {
        // Previous PageRoute trigger visible
        //
        // 前一个PageRoute触发visible
        _sendEventsToLastPageRoute([LifecycleEvent.visible]);
      }
      break;
    case AppLifecycleState.inactive: // inactive
      // Top route trigger inactive
      //
      // 最上面的route触发inactive
      _sendEventsToLastRoute([LifecycleEvent.inactive]);
      break;
    case AppLifecycleState.paused: // invisible
      // Top route trigger invisible
      //
      // 最上面的route触发invisible
      _sendEventsToLastRoute([LifecycleEvent.invisible]);
      if (_history.last.route is! PageRoute) {
        // Previous PageRoute trigger invisible
        //
        // 前一个PageRoute触发invisible
        _sendEventsToLastPageRoute([LifecycleEvent.invisible]);
      }
      break;
    case AppLifecycleState.detached:
      break;
  }
}