NavigatorState 不公开获取当前路由路径的 API,Route 也不公开确定路由路径的 API。路由可以(并且通常是)匿名的。您现在可以使用 isCurrent 方法确定给定的 Route 是否位于导航器堆栈的顶部,但这对于您的用例来说不是很方便。
我建议您对这个问题采取不同的方法,并且根本不要倒退到根目录。相反,为BottomNavigationBar 的每个窗格使用不同的Navigator 小部件。这样,您就不必在窗格之间切换时倒回堆栈。您可以将 Navigator 小部件包装在 Opacity 和 IgnorePointer 小部件中,以便在它们不应该可见时隐藏它们,而不会破坏它们的堆栈。
import 'package:flutter/material.dart';
void main() {
runApp(new MyApp());
}
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return new MaterialApp(
home: new MyHomePage(),
);
}
}
class SecurePage extends StatelessWidget {
final int index;
SecurePage(this.index);
Widget build(BuildContext context) {
return new Material(
color: Colors.amber,
child: new InkWell(
child: new Center(
child: new Icon(
Icons.security,
color: Colors.white,
size: index * 100.0 + 20.0,
),
),
onTap: () {
Navigator.of(context).push(
new MaterialPageRoute(
builder: (BuildContext context) {
return new SecurePage(index + 1);
},
),
);
},
),
);
}
}
class VerifiedPage extends StatelessWidget {
final int index;
VerifiedPage(this.index);
Widget build(BuildContext context) {
return new Material(
color: Colors.green,
child: new InkWell(
child: new Center(
child: new Icon(
Icons.verified_user,
color: Colors.white,
size: index * 100.0 + 20.0,
),
),
onTap: () {
Navigator.of(context).push(
new MaterialPageRoute(
builder: (BuildContext context) {
return new VerifiedPage(index + 1);
},
),
);
},
),
);
}
}
class MyHomePage extends StatefulWidget {
@override
State createState() => new MyHomePageState();
}
class MyHomePageState extends State<MyHomePage> {
int _page = 0;
List<Widget> initialWidgets = <Widget>[
new SecurePage(0),
new VerifiedPage(0),
];
Widget build(BuildContext context) {
return new Scaffold(
body: new Stack(
children: new List<Widget>.generate(initialWidgets.length, (int index) {
return new IgnorePointer(
ignoring: index != _page,
child: new Opacity(
opacity: _page == index ? 1.0 : 0.0,
child: new Navigator(
onGenerateRoute: (RouteSettings settings) {
return new MaterialPageRoute(
builder: (_) => initialWidgets[index],
);
},
),
),
);
}),
),
bottomNavigationBar: new BottomNavigationBar(
currentIndex: _page,
onTap: (int index) {
setState(() {
_page = index;
});
},
items: <BottomNavigationBarItem>[
new BottomNavigationBarItem(
icon: new Icon(Icons.security),
title: new Text('Secure'),
),
new BottomNavigationBarItem(
icon: new Icon(Icons.verified_user),
title: new Text('Verified'),
),
],
),
);
}
}