刷卡时是否可以通过编程方式更改TabBar指示器？
我已经尝试过使用构建器来获取索引，但是我还没有运气..我敢肯定必须有一种方法可以做到这一点，但是还没有弄清楚
Color _indicatorColor(index) {
switch (index) {
case 0:
return Colors.purple;
break;
case 1:
return colorInfoLighter;
break;
case 2:
return Colors.pink;
break;
}
}
Widget _buildScreen() {
var index;
return Scaffold(
appBar: AppBar(),
bottomNavigationBar: TabBar(
onTap: (_) {
setState(() {});
},
indicatorWeight: 4,
indicatorColor: _indicatorColor(index),
tabs: [
_requestedLabel(),
_completedLabel(),
_cancelledLabel(),
]),
body: Container(
child: TabBarView(children: [
_requestedTab(),
_completedTab(),
_cancelledTab(),
]),
),
);
}
@override
Widget build(BuildContext context) {
return DefaultTabController(
length: 3,
child: _buildScreen(),
);
}
您的意思是更改标签吗？
import 'dart:math';
import 'package:flutter/material.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: MyHomePage(),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({
Key key,
}) : super(key: key);
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage>
with SingleTickerProviderStateMixin {
final colors = [Colors.purple, Colors.green, Colors.pink];
Color indicatorColor;
TabController _controller;
@override
void initState() {
super.initState();
_controller = TabController(length: 3, vsync: this)
..addListener(() {
setState(() {
indicatorColor = colors[_controller.index];
});
});
indicatorColor = colors[0];
}
Widget _buildScreen() {
return Scaffold(
appBar: AppBar(),
bottomNavigationBar: Container(
color: Colors.blue,
child: TabBar(
labelColor: Colors.black,
controller: _controller,
indicatorWeight: 4,
indicatorColor: indicatorColor,
tabs: [
Tab(
child: Container(
child: Text('A'),
),
),
Tab(
child: Text('B'),
),
Tab(
child: Text('C'),
),
]),
),
body: Container(
child: TabBarView(
controller: _controller,
children: [
Center(
child: Text('aa'),
),
Center(
child: Text('bb'),
),
Center(
child: Text('cc'),
),
],
),
),
);
}
@override
Widget build(BuildContext context) {
return DefaultTabController(
length: 3,
child: _buildScreen(),
);
}
}
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我来说两句