如何在Flutter中通过Navigator测试导航

在flutter仓库中的导航器测试中，他们使用NavigatorObserver类观察导航：

class TestObserver extends NavigatorObserver {  onObservation onPushed;  onObservation onPopped;  onObservation onRemoved;  onObservation onReplaced;  @override  void didPush(Route<dynamic> route, Route<dynamic> previousRoute) {    if (onPushed != null) {      onPushed(route, previousRoute);    }  }  @override  void didPop(Route<dynamic> route, Route<dynamic> previousRoute) {    if (onPopped != null) {      onPopped(route, previousRoute);    }  }  @override  void didRemove(Route<dynamic> route, Route<dynamic> previousRoute) {    if (onRemoved != null)      onRemoved(route, previousRoute);  }  @override  void didReplace({ Route<dynamic> oldRoute, Route<dynamic> newRoute }) {    if (onReplaced != null)      onReplaced(newRoute, oldRoute);  }}

看起来它应该可以满足您的要求，但是它只能在顶层（MaterialApp）上运行，我不确定是否可以仅将其提供给小部件。