flutter - 使用颤动向下滚动时如何隐藏bottomAppBar
问题描述
我有一个简单BottomAppBar的代码如下：
bottomNavigationBar: BottomAppBar(
elevation: 0,
shape: CircularNotchedRectangle(),
notchMargin: 10,
child: Container(
height: 60,
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: <Widget>[
Row(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
MaterialButton(
padding: EdgeInsets.all(0),
minWidth: 155,
onPressed: () {
setState(() {
// currentScreen =
// Chat(); // if user taps on this dashboard tab will be active
currentTab = 1;
});
},
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Icon(
Icons.home,
color: currentTab == 1 ? Colors.blue : Colors.grey,
),
Text(
'Home',
style: TextStyle(
color: currentTab == 1 ? Colors.blue : Colors.grey,
),
),
],
),
)
],
),
// Right Tab bar icons
Row(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
MaterialButton(
padding: EdgeInsets.all(0),
minWidth: 60,
onPressed: () {
setState(() {
// currentScreen =
// Settings(); // if user taps on this dashboard tab will be active
currentTab = 3;
});
},
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Icon(
Icons.view_list,
color: currentTab == 3 ? Colors.blue : Colors.grey,
),
Text(
'Property List',
style: TextStyle(
color: currentTab == 3 ? Colors.blue : Colors.grey,
),
),
],
),
),
MaterialButton(
padding: EdgeInsets.all(0),
minWidth: 77,
onPressed: () {
setState(() {
// currentScreen =
// Settings(); // if user taps on this dashboard tab will be active
currentTab = 4;
});
},
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Icon(
Icons.location_searching,
color: currentTab == 4 ? Colors.blue : Colors.grey,
),
Text(
'Map',
style: TextStyle(
color: currentTab == 4 ? Colors.blue : Colors.grey,
),
),
],
),
),
],
)
],
),
),
),
编辑：
这是我的全部代码：
// import 'package:provider/provider.dart';
import 'package:flutter/rendering.dart';
import '../providers/properties.dart';
import '../providers/cities.dart';
import '../providers/property.dart';
import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
// import './model/homelist.dart';
// import './providers/properties.dart';
// import './providers/properties.dart';
import '../widgets/properties_grid.dart';
// import '../providers/property.dart';
import '../app_theme.dart';
// import './widgets/property_item.dart';
class MyHomePage extends StatefulWidget {
const MyHomePage({Key key}) : super(key: key);
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> with TickerProviderStateMixin {
int currentTab = 0;
ScrollController _scrollController = ScrollController();
bool _showBottomBar = true;
_scrollListener() {
if (_scrollController.position.userScrollDirection ==
ScrollDirection.reverse) {
setState(() {
_showBottomBar = false;
});
} else if (_scrollController.position.userScrollDirection ==
ScrollDirection.forward) {
setState(() {
_showBottomBar = true;
});
}
}
// final PageStorageBucket bucket = PageStorageBucket();
var _showOnlyFavorites = false;
// List<HomeList> homeList = HomeList.homeList;
AnimationController animationController;
bool multiple = true;
@override
void initState() {
animationController = AnimationController(
duration: const Duration(milliseconds: 2000), vsync: this);
super.initState();
}
Future<bool> getData() async {
await Future<dynamic>.delayed(const Duration(milliseconds: 0));
return true;
}
@override
void dispose() {
animationController.dispose();
super.dispose();
}
@override
Widget build(BuildContext context) {
// final properties = Provider.of<Properties>(context, listen: false);
return Scaffold(
extendBody: true,
floatingActionButton: FloatingActionButton(
child: Icon(Icons.add),
onPressed: () {},
),
floatingActionButtonLocation: FloatingActionButtonLocation.centerDocked,
bottomNavigationBar: BottomAppBar(
elevation: 0,
shape: CircularNotchedRectangle(),
notchMargin: 10,
child: Container(
height: 60,
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: <Widget>[
Row(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
MaterialButton(
padding: EdgeInsets.all(0),
minWidth: 155,
onPressed: () {
setState(() {
// currentScreen =
// Chat(); // if user taps on this dashboard tab will be active
currentTab = 1;
});
},
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Icon(
Icons.home,
color: currentTab == 1 ? Colors.blue : Colors.grey,
),
Text(
'Home',
style: TextStyle(
color: currentTab == 1 ? Colors.blue : Colors.grey,
),
),
],
),
)
],
),
// Right Tab bar icons
Row(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
MaterialButton(
padding: EdgeInsets.all(0),
minWidth: 60,
onPressed: () {
setState(() {
// currentScreen =
// Settings(); // if user taps on this dashboard tab will be active
currentTab = 3;
});
},
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Icon(
Icons.view_list,
color: currentTab == 3 ? Colors.blue : Colors.grey,
),
Text(
'Property List',
style: TextStyle(
color: currentTab == 3 ? Colors.blue : Colors.grey,
),
),
],
),
),
MaterialButton(
padding: EdgeInsets.all(0),
minWidth: 77,
onPressed: () {
setState(() {
// currentScreen =
// Settings(); // if user taps on this dashboard tab will be active
currentTab = 4;
});
},
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Icon(
Icons.location_searching,
color: currentTab == 4 ? Colors.blue : Colors.grey,
),
Text(
'Map',
style: TextStyle(
color: currentTab == 4 ? Colors.blue : Colors.grey,
),
),
],
),
),
],
)
],
),
),
),
backgroundColor: AppTheme.white,
body: Stack(
children: <Widget>[
FutureBuilder<bool>(
future: getData(),
builder: (BuildContext context, AsyncSnapshot<bool> snapshot) {
if (!snapshot.hasData) {
return const SizedBox();
} else {
return Padding(
padding:
EdgeInsets.only(top: MediaQuery.of(context).padding.top),
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
appBar(),
Expanded(
child: FutureBuilder<bool>(
future: getData(),
builder: (BuildContext context,
AsyncSnapshot<bool> snapshot) {
if (!snapshot.hasData) {
return const SizedBox();
} else {
return ChangeNotifierProvider(
create: (context) => Properties(),
child: PropertiesGrid(_showOnlyFavorites),
);
}
},
),
),
],
),
);
}
},
),
],
),
);
}
Widget appBar() {
return SizedBox(
height: AppBar().preferredSize.height,
child: Row(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Padding(
padding: const EdgeInsets.only(top: 8, left: 8),
child: Container(
width: AppBar().preferredSize.height - 8,
height: AppBar().preferredSize.height - 8,
),
),
Expanded(
child: Center(
child: Padding(
padding: const EdgeInsets.only(top: 4),
child:
Image.asset('assets/images/logo.png', fit: BoxFit.contain),
),
),
),
Padding(
padding: const EdgeInsets.only(top: 8, right: 8),
child: Container(
width: AppBar().preferredSize.height - 8,
height: AppBar().preferredSize.height - 8,
color: Colors.white,
child: Material(
color: Colors.transparent,
child: InkWell(
borderRadius:
BorderRadius.circular(AppBar().preferredSize.height),
child: Icon(
Icons.location_on,
color: AppTheme.dark_grey,
),
onTap: () {
setState(() {
multiple = !multiple;
});
},
),
),
),
),
],
),
);
}
已编辑 2
return Scaffold(
resizeToAvoidBottomPadding: false,
extendBody: true,
floatingActionButton: FloatingActionButton(
child: Icon(Icons.add),
onPressed: () {},
),
floatingActionButtonLocation: FloatingActionButtonLocation.centerDocked,
bottomNavigationBar: AnimatedContainer(
duration: Duration(milliseconds: 500),
child: _showBottomBar
? BottomAppBar(
elevation: 0,
shape: CircularNotchedRectangle(),
notchMargin: 10,
child: Container(
height: 60,
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: <Widget>[
Row(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
MaterialButton(
padding: EdgeInsets.all(0),
minWidth: 155,
onPressed: () {
setState(() {
// currentScreen =
// Chat(); // if user taps on this dashboard tab will be active
currentTab = 1;
});
},
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Icon(
Icons.home,
color: currentTab == 1
? Colors.blue
: Colors.grey,
),
Text(
'Home',
style: TextStyle(
color: currentTab == 1
? Colors.blue
: Colors.grey,
),
),
],
),
)
],
),
// Right Tab bar icons
Row(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
MaterialButton(
padding: EdgeInsets.all(0),
minWidth: 60,
onPressed: () {
setState(() {
// currentScreen =
// Settings(); // if user taps on this dashboard tab will be active
currentTab = 3;
});
},
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Icon(
Icons.view_list,
color: currentTab == 3
? Colors.blue
: Colors.grey,
),
Text(
'Property List',
style: TextStyle(
color: currentTab == 3
? Colors.blue
: Colors.grey,
),
),
],
),
),
MaterialButton(
padding: EdgeInsets.all(0),
minWidth: 77,
onPressed: () {
setState(() {
// currentScreen =
// Settings(); // if user taps on this dashboard tab will be active
currentTab = 4;
});
},
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Icon(
Icons.location_searching,
color: currentTab == 4
? Colors.blue
: Colors.grey,
),
Text(
'Map',
style: TextStyle(
color: currentTab == 4
? Colors.blue
: Colors.grey,
),
),
],
),
),
],
)
],
),
),
)
: Container(
color: Colors.white,
width: MediaQuery.of(context).size.width,
),
),
backgroundColor: AppTheme.white,
body: Stack(
children: <Widget>[
FutureBuilder<bool>(
future: getData(),
builder: (BuildContext context, AsyncSnapshot<bool> snapshot) {
if (!snapshot.hasData) {
return const SizedBox();
} else {
return Padding(
padding:
EdgeInsets.only(top: MediaQuery.of(context).padding.top),
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
appBar(),
Expanded(
child: FutureBuilder<bool>(
future: getData(),
builder: (BuildContext context,
AsyncSnapshot<bool> snapshot) {
if (!snapshot.hasData) {
return const SizedBox();
} else {
return ChangeNotifierProvider(
create: (context) => Properties(),
child: PropertiesGrid(_showOnlyFavorites),
);
}
},
),
),
],
),
);
}
},
),
],
),
);
我现在需要在向下滚动时隐藏这个底栏......有没有办法用一个简单的动画来做到这一点？？......
我还在中心有一个浮动操作按钮，所以如果有可能FloatButton在向下滚动时用栏隐藏它？？...
希望有人帮我解决这个问题...
解决方案
ScrollController 用于管理小部件的滚动方向，它有一个回调，如
_scrollController.addListener(_scrollListener);
例子：
class HomeScreen extends StatefulWidget {
@override
_HomeScreenState createState() => _HomeScreenState();
}
class _HomeScreenState extends State<HomeScreen> {
int currentTab = 1;
ScrollController _scrollController = ScrollController();
bool _showBottomBar = true;
_scrollListener() {
if (_scrollController.position.userScrollDirection ==
ScrollDirection.reverse) {
setState(() {
_showBottomBar = false;
});
} else if (_scrollController.position.userScrollDirection ==
ScrollDirection.forward) {
setState(() {
_showBottomBar = true;
});
}
}
@override
void initState() {
_scrollController.addListener(_scrollListener);
super.initState();
}
@override
Widget build(BuildContext context) {
return Scaffold(
resizeToAvoidBottomPadding: false,
bottomNavigationBar: AnimatedContainer(
duration: Duration(milliseconds: 500),
height: 60.0,
child: _showBottomBar? BottomAppBar(
elevation: 0,
shape: CircularNotchedRectangle(),
notchMargin: 10,
child: Container(
height: 60,
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: <Widget>[
Row(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
MaterialButton(
padding: EdgeInsets.all(0),
minWidth: 155,
onPressed: () {
setState(() {
// currentScreen =
// Chat(); // if user taps on this dashboard tab will be active
currentTab = 1;
});
},
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Icon(
Icons.home,
color: currentTab == 1 ? Colors.blue : Colors.grey,
),
Text(
'Home',
style: TextStyle(
color: currentTab == 1 ? Colors.blue : Colors.grey,
),
),
],
),
)
],
),
// Right Tab bar icons
Row(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
MaterialButton(
padding: EdgeInsets.all(0),
minWidth: 60,
onPressed: () {
setState(() {
// currentScreen =
// Settings(); // if user taps on this dashboard tab will be active
currentTab = 3;
});
},
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Icon(
Icons.view_list,
color: currentTab == 3 ? Colors.blue : Colors.grey,
),
Text(
'Property List',
style: TextStyle(
color: currentTab == 3 ? Colors.blue : Colors.grey,
),
),
],
),
),
MaterialButton(
padding: EdgeInsets.all(0),
minWidth: 77,
onPressed: () {
setState(() {
// currentScreen =
// Settings(); // if user taps on this dashboard tab will be active
currentTab = 4;
});
},
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Icon(
Icons.location_searching,
color: currentTab == 4 ? Colors.blue : Colors.grey,
),
Text(
'Map',
style: TextStyle(
color: currentTab == 4 ? Colors.blue : Colors.grey,
),
),
],
),
),
],
)
],
),
),
): Container(
color: Colors.white,
width: MediaQuery.of(context).size.width,
),
),
appBar: AppBar(),
body: Container(
child: ListView.builder(
controller: _scrollController,
itemCount: 10,
itemBuilder: (ctx, index) {
return Column(
children: <Widget>[
Container(
color: Colors.black54,
width: double.infinity,
height: 120,
),
SizedBox(
height: 20,
)
],
);
}),
),
);
}
}
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