How to implement fragment transaction in Flutter? - flutter

Question

I'm having a Tab Layout at top of the screen and Bottom Navigation view at bottom of the screen.
I need to have a container in the middle and swap the views which is similar to fragment transactions in Android.
How to acheive this in Flutter ?
home: DefaultTabController(
length: prefList.length,
child: Scaffold(
appBar: AppBar(
backgroundColor: const Color(0xff00234a),
bottom: TabBar(
tabs: tabList,
isScrollable: true,
indicatorColor: const Color(0xffffffff),
),
title: Text('Test Demo'),
centerTitle: true,
),
body: Container(
child: TabBarView(
children: tabList,
controller: controller,
),
),
// Set the bottom navigation bar
bottomNavigationBar: Material(
// set the color of the bottom navigation bar
color: const Color(0xff00234a),
// set the tab bar as the child of bottom navigation bar
child: TabBar(
tabs: <Tab>[
Tab(
icon: Icon(Icons.favorite),
),
Tab(
icon: Icon(Icons.adb),
),
Tab(
icon: Icon(Icons.airplay),
),
Tab(
icon: Icon(Icons.gamepad),
),
Tab(
icon: Icon(Icons.videogame_asset),
),
],
// setup the controller
controller: controller,
),
),
),
),
);
}
I need to replace the TabView widget with something like Container layout in Android which is used to replace different fragments !

Answer 1

from flutter documentation you can achieve a bottom nav using this
int _selectedIndex = 0;
static const TextStyle optionStyle = TextStyle(fontSize: 30, fontWeight: FontWeight.bold);
static const List<Widget> _widgetOptions = <Widget>[
Text(
'Index 0: Home',
style: optionStyle,
),
Text(
'Index 1: Business',
style: optionStyle,
),
Text(
'Index 2: School',
style: optionStyle,
),
];
void _onItemTapped(int index) {
setState(() {
_selectedIndex = index;
});
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: const Text('BottomNavigationBar Sample'),
),
body: Center(
child: _widgetOptions.elementAt(_selectedIndex),
),
bottomNavigationBar: BottomNavigationBar(
items: const <BottomNavigationBarItem>[
BottomNavigationBarItem(
icon: Icon(Icons.home),
title: Text('Home'),
),
BottomNavigationBarItem(
icon: Icon(Icons.business),
title: Text('Business'),
),
BottomNavigationBarItem(
icon: Icon(Icons.school),
title: Text('School'),
),
],
currentIndex: _selectedIndex,
selectedItemColor: Colors.amber[800],
onTap: _onItemTapped,
),
);
}
for tabbed screen
//lifted from a project im doing
#override
Widget build(BuildContext context) {
return DefaultTabController(
length: 4,
child: Scaffold(
appBar: AppBar(centerTitle: true,
title: Text("tabs", style: TextStyle(fontWeight: FontWeight.bold, color: Colors.white)),
bottom: TabBar(
indicatorColor: Colors.white,
tabs: <Widget>[
Tab(
icon: Image.asset(
"assets/icons/tools.png",
height: 38,
),
child: Text("s1",style: TextStyle(fontSize: 10),),
),
Tab(
icon: Image.asset(
"assets/icons/il.png",
height: 38,
),
child: Text("s2",style: TextStyle(fontSize: 10)),
),
Tab(
icon: Icon(Icons.lock),
child: Text("s3"),
),
Tab(
icon: Icon(Icons.lock),
child: Text("s4"),
),
],
),
),
body: TabBarView(children: <Widget>[
Screen1(),
Screen2(),
Screen3(),
Screen4()
],),
),
);