一种简单的方法是将有状态小部件的“状态”作为参数传递给“模型”。
像这样:
class Model extends ChangeNotifier {
Model(this.yourState);
YourState yourState;
bool get _isMounted => yourState.mounted;
}
class YourState extends State<YourStatefulWidget> {
Model model;
@override
void initState() {
super.initState();
model = Model(this);
}
@override
Widget build(BuildContext context) {
// your code..
}
}
我认为你不需要检查State
是否已安装。您只需要检查模型是否已被处置。您可以覆盖dispose()
中的方法ChangeNotifier
:
class Model extends ChangeNotifier {
bool _isDisposed = false;
void run() async {
await Future.delayed(Duration(seconds: 10));
if (!_isDisposed) {
notifyListeners();
}
}
@override
void dispose() {
super.dispose();
_isDisposed = true;
}
}
并且不要忘记处置Model
当。。。的时候State
被处置:
class YourState extends State {
Model model;
@override
void initState() {
super.initState();
model = Model();
}
@override
void dispose() {
model?.dispose();
super.dispose();
}
/// Your build code...
}
或者你可以使用ChangeNotifierProvider
包装内Provider https://pub.dev/packages/provider,它将帮助您处置Model
自动地。
class YourState extends State {
Model model;
@override
void initState() {
super.initState();
model = Model();
}
@override
Widget build(BuildContext context) {
return ChangeNotifierProvider<Model>(
builder: (build) => model,
child: Container(
child: Consumer<Model>(
builder: (context, model, widget) => Text("$model"),
),
),
);
}
}