如何在颤动中禁用手机后按

Question

我是 Flutter 开发的新手。谁能分享我如何在flutter 中禁用后按？

在Android中，我们可以使用onbackpressed方法。

@Override
public void onBackPressed() {
  // super.onBackPressed(); commented this line in order to disable back press
  //Write your code here
  Toast.makeText(getApplicationContext(), "Back press disabled!", Toast.LENGTH_SHORT).show();
}

在flutter怎么可能呢？

Answer 1

将您的小部件包装在 WillPopScope 中，并在 onWillPop 属性中返回错误的 Future

    @override
    Widget build(BuildContext context) {
      return WillPopScope(
        onWillPop: () => Future.value(false),
        child: Scaffold(
          appBar: AppBar(
            title: const Text("Home Page"),
          ),
          body: Center(
            child: const Text("Home Page"),
          ),
        ),
      );
    }

请参阅此文档：https://api.flutter.dev/flutter/widgets/WillPopScope-class.html

Answer 2

最简单的方法是使用WillPopScope，但如果出于某种原因您不想或不能使用WillPopScope 小部件，这里有另一种方法。

class MyWidget extends StatefulWidget {
  @override
  _MyWidgetState createState() => _MyWidgetState();
}

class _MyWidgetState extends State<MyWidget> {
  ModalRoute<dynamic> _route;

  @override
  void didChangeDependencies() {
    super.didChangeDependencies();
    _route?.removeScopedWillPopCallback(_onWillPop);
    _route = ModalRoute.of(context);
    _route?.addScopedWillPopCallback(_onWillPop);
  }

  @override
  void dispose() {
    _route?.removeScopedWillPopCallback(_onWillPop);
    super.dispose();
  }

  Future<bool> _onWillPop() => Future.value(false);

  @override
  Widget build(BuildContext context) => Container();
}