一统天下 flutter - 路由和导航: WillPopScope - 出栈拦截
一统天下 flutter - 路由和导航: WillPopScope - 出栈拦截
示例如下:
lib\route\will_pop_scope.dart
/*
* WillPopScope - 出栈拦截
*/
import 'package:flutter/material.dart';
import 'package:flutter_demo/helper.dart';
class WillPopScopeDemo extends StatefulWidget {
const WillPopScopeDemo({Key? key}) : super(key: key);
@override
_WillPopScopeDemoState createState() => _WillPopScopeDemoState();
}
class _WillPopScopeDemoState extends State<WillPopScopeDemo> {
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: null,
/// 通过 WillPopScope 拦截当前页面的 pop
body: WillPopScope(
child: Center(
child: MyButton(
onPressed: () {
/// 注意：
/// 如果通过 Navigator.of(context).pop() 出栈，则走不到 WillPopScope 的 onWillPop
/// 要想走到 WillPopScope 的 onWillPop 需要使用 Navigator.of(context).maybePop()
Navigator.of(context).maybePop();
},
child: const Text('关闭'),
),
),
/// 当前页面将要 pop 时触发的事件
onWillPop: () async {
var result = await _showDialog(context);
/// return true; 代表允许出栈
/// return false; 代表禁止出栈
return result ?? false;
},
),
);
}
Future<bool?> _showDialog(BuildContext context) {
return showDialog<bool>(
context: context,
builder: (BuildContext context) => AlertDialog(
content: const Text('是否退出？'),
actions: <Widget>[
TextButton(
onPressed: () => Navigator.pop(context, true),
child: const Text('是'),
),
TextButton(
onPressed: () => Navigator.pop(context, false),
child: const Text('否'),
),
],
),
);
}
}
