我正试图超越 updateShouldNotify 在里面 TickerMode ( https://api.flutter.dev/flutter/widgets/TickerMode-class.html ).它被列为一种方法,但当我点击代码时,它实际上没有这种方法。
updateShouldNotify
TickerMode
我愿意:
class MyTickerMode extends TickerMode { const MyTickerMode( {Key key, @required bool enabled, Widget child}) : super(key: key, enabled: enabled, child: child); @override bool updateShouldNotify(TickerMode oldWidget) => false; }
这将返回错误 The method doesn't override an inherited method. #override_on_non_overriding_member .
The method doesn't override an inherited method. #override_on_non_overriding_member
为什么? 我也试过了 updateShouldNotify(covariant TickerMode oldWidget) 和 updateShouldNotify(_) .
updateShouldNotify(covariant TickerMode oldWidget)
updateShouldNotify(_)
没有 updateShouldNotify() 方法 TickerMode 。当类扩展时,需要重写此方法 InheritedWidget .你可以在 _EffectiveTickerMode 在里面 ticker_provider
updateShouldNotify()
InheritedWidget
_EffectiveTickerMode
ticker_provider
最后 The method doesn't override an inherited method 尝试重写可扩展类中不存在的方法时出错。
The method doesn't override an inherited method