是否有一种方法可以在特定页面上禁用Android后退按钮?
class WakeUpApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return new MaterialApp(
title: "Time To Wake Up ?",
home: new WakeUpHome(),
routes: <String, WidgetBuilder>{
'/pageOne': (BuildContext context) => new pageOne(),
'/pageTwo': (BuildContext context) => new pageTwo(),
},
);
}
}
在第一页，我有一个按钮去第二页:
new FloatingActionButton(
onPressed: () {
Navigator.of(context).pushNamed('/pageTwo');
},
)
我的问题是，如果我按下android屏幕底部的后退箭头，我就会回到pageOne。我想这个按钮不显示在所有。
理想情况下，除非用户的手指持续按在屏幕上5秒钟，否则我不希望用户有任何办法离开屏幕。(我正在尝试为幼儿编写一个应用程序，希望只有父母能够导航出特定的屏幕)。
尝试这将杀死你的应用程序状态
@override
Widget build(BuildContext context) {
return WillPopScope(
////////////////
onWillPop: () => showDialog<bool>(
context: context,
builder: (c) => AlertDialog(
title: Text(
'Warning',
textAlign: TextAlign.center,
),
content: Text('Are you sure to exit?'),
actions: [
TextButton(
style: TextButton.styleFrom(
primary: Colors.green,
),
onPressed: () async {
exit(0);// kill app
},
child: Text('Yes'),
),
TextButton(
style: TextButton.styleFrom(
primary: Colors.red,
),
onPressed: () => Navigator.pop(c, false),
child: Text('No'),
)
],
),
),
/////////////////////
child: Scaffold(),
);
}
答案也许你知道使用WillPopScope，但不幸的是，在IOS上你不能滑动回上一页，所以让我们自定义你的MaterialPageRoute:
class CustomMaterialPageRoute<T> extends MaterialPageRoute<T> {
@protected
bool get hasScopedWillPopCallback {
return false;
}
CustomMaterialPageRoute({
@required WidgetBuilder builder,
RouteSettings settings,
bool maintainState = true,
bool fullscreenDialog = false,
}) : super(
builder: builder,
settings: settings,
maintainState: maintainState,
fullscreenDialog: fullscreenDialog,
);
}
现在你可以使用WillPopScope并向后滑动在IOS上工作。详细答案在这里:https://github.com/flutter/flutter/issues/14203#issuecomment-540663717
这里有一个替代的解决方案，如果你是用零安全编码。您需要禁用默认的后退按钮，并将其替换为IconButton。在本例中，当用户在退出前单击后退按钮确认时，我将按下AlertDialog。您可以替换此函数并将用户发送到任何其他页面
return WillPopScope(
onWillPop: () async => false,
child: Scaffold(
appBar: AppBar(
automaticallyImplyLeading: true,
title: Text(),
leading: IconButton(
icon: Icon(Icons.arrow_back),
onPressed: () => showDialog<bool>(
context: context,
builder: (c) => AlertDialog(
title: Text('Warning'),
content: Text('Are you sure you want to exit?'),
),
actions: [
TextButton(
child: Text('Yes'),
onPressed: () {
Navigator.pop(c, true);
Navigator.pop(context);
}),
TextButton(
child: Text('No'),
onPressed: () => Navigator.pop(c, false),
),
],
),
),
),
),
我把这个贴在这里，以防有人发现这个，并希望他们能找到一个简单的例子
https://gist.github.com/b-cancel/0ca372017a25f0c120b14dfca3591aa5
import 'package:flutter/material.dart';
import 'dart:async';
void main() => runApp(new BackButtonOverrideDemoWidget());
class BackButtonOverrideDemoWidget extends StatefulWidget{
@override
_BackButtonOverrideDemoWidgetState createState() => new _BackButtonOverrideDemoWidgetState();
}
class _BackButtonOverrideDemoWidgetState extends State<BackButtonOverrideDemoWidget> with WidgetsBindingObserver{
//-------------------------Test Variable
bool isBackButtonActivated = false;
//-------------------------Required For WidgetsBindingObserver
@override
void initState() {
super.initState();
WidgetsBinding.instance.addObserver(this);
}
@override
void dispose() {
WidgetsBinding.instance.removeObserver(this);
super.dispose();
}
//-------------------------Function That Triggers when you hit the back key
@override
didPopRoute(){
bool override;
if(isBackButtonActivated)
override = false;
else
override = true;
return new Future<bool>.value(override);
}
//-------------------------Build Method
@override
Widget build(BuildContext context) {
return new Directionality(
textDirection: TextDirection.ltr,
child: new Container(
color: (isBackButtonActivated) ? Colors.green : Colors.red,
child: new Center(
child: new FlatButton(
color: Colors.white,
onPressed: () {
isBackButtonActivated = !isBackButtonActivated;
setState(() {});
},
child: (isBackButtonActivated) ?
new Text("DeActive the Back Button") : new Text("Activate the Back Button"),
)
)
),
);
}
}
