1. int _selectedIndex = 0;
2. static const TextStyle optionStyle = TextStyle(fontSize: 30, fontWeight: FontWeight.bold);
3. static const List<Widget> _widgetOptions = <Widget>[
4. Text(
5. 'Index 0: Home',
6. style: optionStyle,
7. ),
8. Text(
9. 'Index 1: Business',
10. style: optionStyle,
11. ),
12. Text(
13. 'Index 2: School',
14. style: optionStyle,
15. ),
16. ];
18. void _onItemTapped(int index) {
19. setState(() {
20. _selectedIndex = index;
21. });
22. }
24. @override
25. Widget build(BuildContext context) {
26. return Scaffold(
27. appBar: AppBar(
28. title: const Text('BottomNavigationBar Sample'),
29. ),
30. body: Center(
31. child: _widgetOptions.elementAt(_selectedIndex),
32. ),
33. bottomNavigationBar: BottomNavigationBar(
34. items: const <BottomNavigationBarItem>[
35. BottomNavigationBarItem(
36. icon: Icon(Icons.home),
37. title: Text('Home'),
38. ),
39. BottomNavigationBarItem(
40. icon: Icon(Icons.business),
41. title: Text('Business'),
42. ),
43. BottomNavigationBarItem(
44. icon: Icon(Icons.school),
45. title: Text('School'),
46. ),
47. ],
48. currentIndex: _selectedIndex,
49. selectedItemColor: Colors.amber[800],
50. onTap: _onItemTapped,
51. ),
52. );
53. }

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,
    ),
  );
}