带有页面视图的自定义导航栏 [Flutter]
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【中文标题】带有页面视图的自定义导航栏 [Flutter]【英文标题】：Custom navigation bar with page view [Flutter] 【发布时间】：2021-03-08 20:12:34 【问题描述】：我正在尝试使用 PageView 在 Flutter 中实现一个自定义的 BottomNavigationBar，以便在同一 Scaffold 中包含有状态小部件的不同页面之间滑动。
虽然我可以点击导航栏并更改页面，但我无法实现页面浏览滑动手势，同时还更改了指示所选页面的 icon_button 的颜色。我能够完美地使用 BottomNavigationBarItem 做到这一点，但我想使用自定义设计。
是否可以将包含不同 Icon_buttons 的 Stack Widget 转换为 BottomNavigationBarItem，以便我们可以使用 onTap 和 currentindex 函数来简化它？出路是什么？
import 'package:app/screens/screens.dart';
import 'package:flutter/material.dart';
class AppBottomNav extends StatefulWidget
AppBottomNav(Key key) : super(key: key);
@override
_AppBottomNavState createState() => _AppBottomNavState();
class _AppBottomNavState extends State<AppBottomNav>
int currentIndex = 0;
var pages = [HomeScreen(), HistoryScreen(), ScanScreen(),
BleConnectionScreen(), AccountScreen()];
var _appPageController = PageController();
setBottomBarIndex(index)
setState(()
currentIndex = index;
);
@override
Widget build(BuildContext context)
final Size size = MediaQuery.of(context).size;
return Scaffold(
backgroundColor: Colors.white.withAlpha(100),
body: PageView(
scrollDirection: Axis.horizontal,
children: pages,
onPageChanged: (index)
setState(()
currentIndex = index;
);
,
controller: _appPageController,
),
bottomNavigationBar:
Stack(
children: [
Positioned(
bottom: 0,
left: 0,
child: Container(
width: size.width,
height: 80,
child: Stack(
overflow: Overflow.visible,
children: [
CustomPaint(
size: Size(size.width, 80),
painter: BNBCustomPainter(),
),
Center(
heightFactor: 0.6,
child: FloatingActionButton(backgroundColor: Colors.green[700],
child: Icon(Icons.search), // Analyze Button
elevation: 0.1,
onPressed: () ),
),
Container(
width: size.width,
height: 80,
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: [
IconButton(
icon: Icon(
Icons.home,
color: currentIndex == 0 ? Colors.green[700] : Colors.grey.shade400,
),
onPressed: ()
setBottomBarIndex(0);
,
splashColor: Colors.white,
),
IconButton(
icon: Icon(
Icons.history,
color: currentIndex == 1 ? Colors.green[700] : Colors.grey.shade400,
),
onPressed: ()
setBottomBarIndex(1);
),
Container(
width: size.width * 0.20,
),
IconButton(
icon: Icon(
Icons.bluetooth,
color: currentIndex == 2 ? Colors.green[700] : Colors.grey.shade400,
),
onPressed: ()
setBottomBarIndex(2);
),
IconButton(
icon: Icon(
Icons.account_circle,
color: currentIndex == 3 ? Colors.green[700] : Colors.grey.shade400,
),
onPressed: ()
setBottomBarIndex(3);
),
],
),
)
],
),
),
)
],
),
);
void _onTappedBar(int value)
setState(()
currentIndex = value;
);
_appPageController.jumpToPage(value);
class BNBCustomPainter extends CustomPainter
@override
void paint(Canvas canvas, Size size)
Paint paint = new Paint()
..color = Colors.white
..style = PaintingStyle.fill;
Path path = Path();
path.moveTo(0, 20); // Start
path.quadraticBezierTo(size.width * 0.20, 0, size.width * 0.35, 0);
path.quadraticBezierTo(size.width * 0.40, 0, size.width * 0.40, 20);
path.arcToPoint(Offset(size.width * 0.60, 20), radius: Radius.circular(20.0), clockwise: false);
path.quadraticBezierTo(size.width * 0.60, 0, size.width * 0.65, 0);
path.quadraticBezierTo(size.width * 0.80, 0, size.width, 20);
path.lineTo(size.width, size.height);
path.lineTo(0, size.height);
path.lineTo(0, 20);
canvas.drawShadow(path, Colors.black, 5, true);
canvas.drawPath(path, paint);
@override
bool shouldRepaint(CustomPainter oldDelegate)
return false;
【问题讨论】：
我不久前做过类似的事情，但如果你想看看的话，这里使用不同的方法是 DartPad：DartPad 【参考方案1】：您可以在下面复制粘贴运行完整代码
第 1 步：您可以在 bottomNavigationBar 中删除 Stack 和 Positioned 并仅使用 Container
第 2 步：setBottomBarIndex 使用 _appPageController.animateToPage
代码sn-p
bottomNavigationBar: Container(
width: size.width,
height: 80,
child: Stack(
//overflow: Overflow.visible,
children: [
CustomPaint(
...
setBottomBarIndex(index)
setState(()
currentIndex = index;
);
_appPageController.animateToPage(index,
duration: Duration(milliseconds: 500), curve: Curves.ease);
工作演示
完整代码
import 'package:flutter/material.dart';
class AppBottomNav extends StatefulWidget
AppBottomNav(Key key) : super(key: key);
@override
_AppBottomNavState createState() => _AppBottomNavState();
class _AppBottomNavState extends State<AppBottomNav>
int currentIndex = 0;
var pages = [
HomeScreen(),
HistoryScreen(),
ScanScreen(),
BleConnectionScreen(),
AccountScreen()
];
var _appPageController = PageController();
setBottomBarIndex(index)
setState(()
currentIndex = index;
);
_appPageController.animateToPage(index,
duration: Duration(milliseconds: 500), curve: Curves.ease);
@override
Widget build(BuildContext context)
final Size size = MediaQuery.of(context).size;
return Scaffold(
backgroundColor: Colors.white.withAlpha(100),
body: PageView(
scrollDirection: Axis.horizontal,
children: pages,
onPageChanged: (index)
setState(()
currentIndex = index;
);
,
controller: _appPageController,
),
bottomNavigationBar: Container(
width: size.width,
height: 80,
child: Stack(
//overflow: Overflow.visible,
children: [
CustomPaint(
size: Size(size.width, 80),
painter: BNBCustomPainter(),
),
Center(
heightFactor: 0.6,
child: FloatingActionButton(
backgroundColor: Colors.green[700],
child: Icon(Icons.search), // Analyze Button
elevation: 0.1,
onPressed: () ),
),
Container(
width: size.width,
height: 80,
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: [
IconButton(
icon: Icon(
Icons.home,
color: currentIndex == 0
? Colors.green[700]
: Colors.grey.shade400,
),
onPressed: ()
setBottomBarIndex(0);
,
splashColor: Colors.white,
),
IconButton(
icon: Icon(
Icons.history,
color: currentIndex == 1
? Colors.green[700]
: Colors.grey.shade400,
),
onPressed: ()
setBottomBarIndex(1);
),
Container(
width: size.width * 0.20,
),
IconButton(
icon: Icon(
Icons.bluetooth,
color: currentIndex == 2
? Colors.green[700]
: Colors.grey.shade400,
),
onPressed: ()
setBottomBarIndex(2);
),
IconButton(
icon: Icon(
Icons.account_circle,
color: currentIndex == 3
? Colors.green[700]
: Colors.grey.shade400,
),
onPressed: ()
setBottomBarIndex(3);
),
],
),
)
],
),
),
);
void _onTappedBar(int value)
setState(()
currentIndex = value;
);
_appPageController.jumpToPage(value);
class BNBCustomPainter extends CustomPainter
@override
void paint(Canvas canvas, Size size)
Paint paint = new Paint()
..color = Colors.white
..style = PaintingStyle.fill;
Path path = Path();
path.moveTo(0, 20); // Start
path.quadraticBezierTo(size.width * 0.20, 0, size.width * 0.35, 0);
path.quadraticBezierTo(size.width * 0.40, 0, size.width * 0.40, 20);
path.arcToPoint(Offset(size.width * 0.60, 20),
radius: Radius.circular(20.0), clockwise: false);
path.quadraticBezierTo(size.width * 0.60, 0, size.width * 0.65, 0);
path.quadraticBezierTo(size.width * 0.80, 0, size.width, 20);
path.lineTo(size.width, size.height);
path.lineTo(0, size.height);
path.lineTo(0, 20);
canvas.drawShadow(path, Colors.black, 5, true);
canvas.drawPath(path, paint);
@override
bool shouldRepaint(CustomPainter oldDelegate)
return false;
void main()
runApp(MyApp());
class MyApp extends StatelessWidget
@override
Widget build(BuildContext context)
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
visualDensity: VisualDensity.adaptivePlatformDensity,
),
home: AppBottomNav(),
);
class ScanScreen extends StatelessWidget
@override
Widget build(BuildContext context)
return Container(
child: Center(
child: Text(
"Scan",
style: TextStyle(color: Colors.green),
)));
class HistoryScreen extends StatelessWidget
@override
Widget build(BuildContext context)
return Center(child: Text("History"));
class HomeScreen extends StatelessWidget
@override
Widget build(BuildContext context)
return Center(child: Container(color: Colors.blue, child: Text("Home")));
class AccountScreen extends StatelessWidget
@override
Widget build(BuildContext context)
return Center(child: Text("Account"));
class BleConnectionScreen extends StatelessWidget
@override
Widget build(BuildContext context)
return Center(child: Text("BleConnection"));
【讨论】：
我是 Flutter 的新手，非常感谢您的建议和代码，不知道我们可以用容器替换堆栈和位置。老兄，你摇滚！以上是关于带有页面视图的自定义导航栏 [Flutter]的主要内容，如果未能解决你的问题，请参考以下文章