Lifecycle<T extends StatefulWidget> mixin

具备生命周期感知的 StatefulWidget

1.在 StatefulWidget 中，继承/混入此类，使得组件具备生命周期功能

2.在任何你需要的地方构造一个生命周期观察者 LifecycleObserver

3.将观察者绑定到当前对象，即可实现观察者监听组件的生命周期

///某个需要感知生命周期的观察者
class AModel extends LifecycleObserver {
  /// 需要依据生命周期释放的资源
  ScrollController controller = ScrollController();

  @override
  void onLifecycleChanged(LifecycleOwner owner, LifecycleState state) {
    if (state == LifecycleState.onDestroy) {
      ///在组件销毁时释放资源
      controller.dispose();
    }
  }
}

///在 StatefulWidget 中混入 Lifecycle
class _MyPageState extends State<MyPage> with Lifecycle {
  @override
  void initState() {
    super.initState();

    ///绑定观察者
    getLifecycle().addObserver(AModel());
  }

  @override
  Widget build(BuildContext context) {
    return Container();
  }
}

Superclass Constraints

State<T>

Implemented types

LifecycleOwner

Properties

context → BuildContext: The location in the tree where this widget builds.
no setterinherited
hashCode → int: The hash code for this object.
no setterinherited
mounted → bool: Whether this State object is currently in a tree.
no setterinherited
runtimeType → Type: A representation of the runtime type of the object.
no setterinherited
widget → T: The current configuration.
no setterinherited

Methods

activate() → void: Called when this object is reinserted into the tree after having been removed via deactivate.
inherited
build(BuildContext context) → Widget: Describes the part of the user interface represented by this widget.
inherited
deactivate() → void: Called when this object is removed from the tree.
override
debugFillProperties(DiagnosticPropertiesBuilder properties) → void: Add additional properties associated with the node.
inherited
didChangeDependencies() → void: Called when a dependency of this State object changes.
override
didUpdateWidget(covariant T oldWidget) → void: Called whenever the widget configuration changes.
inherited
dispose() → void: Called when this object is removed from the tree permanently.
override
getLifecycle() → LifecycleObservable: 获取被观察者，用来管理观察者
override
getStateful() → State<StatefulWidget>: 获取 StatefulWidget 的 State
override
initState() → void: Called when this object is inserted into the tree.
override
noSuchMethod(Invocation invocation) → dynamic: Invoked when a nonexistent method or property is accessed.
inherited
reassemble() → void: Called whenever the application is reassembled during debugging, for example during hot reload.
inherited
setState(VoidCallback fn) → void: Notify the framework that the internal state of this object has changed.
inherited
toDiagnosticsNode({String? name, DiagnosticsTreeStyle? style}) → DiagnosticsNode: Returns a debug representation of the object that is used by debugging tools and by DiagnosticsNode.toStringDeep.
inherited
toString({DiagnosticLevel minLevel = DiagnosticLevel.info}) → String: A string representation of this object.
inherited
toStringShort() → String: A brief description of this object, usually just the runtimeType and the hashCode.
inherited

Operators

operator ==(Object other) → bool: The equality operator.
inherited

Lifecycle<T extends StatefulWidget> mixin

Properties

Methods

Operators

lifecycle library