navigation_rail_example.dart

import 'package:flutter/material.dart';
import 'package:google_fonts/google_fonts.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: MyStatefulWidget(),
    );
  }
}

class MyStatefulWidget extends StatefulWidget {
  @override
  _MyStatefulWidgetState createState() => _MyStatefulWidgetState();
}

class _MyStatefulWidgetState extends State<MyStatefulWidget> {
  int _selectedIndex = 0;
  List _childern = [
    Container(
      child: Text("HOME"),
      color: Colors.cyan,
    ),
    Container(
      child: Text("FAVORITES"),
      color: Colors.redAccent,
    ),
    Container(
      child: Text("BOOKMARK"),
      color: Colors.greenAccent,
    ),
  ];

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Row(
        children: <Widget>[
          NavigationRail(
            leading: Icon(Icons.home),
            backgroundColor: Colors.cyan,
            elevation: 2,
            extended: true,
            unselectedLabelTextStyle: GoogleFonts.lato(),
            selectedLabelTextStyle: GoogleFonts.pacifico(),
            selectedIndex: _selectedIndex,
            onDestinationSelected: (index) {
              setState(() {
                _selectedIndex = index;
              });
            },
            labelType: NavigationRailLabelType.selected,
            destinations: [
              NavigationRailDestination(
                icon: Icon(Icons.home),
                selectedIcon: Icon(Icons.home),
                label: Text('Home'),
              ),
              NavigationRailDestination(
                icon: Icon(Icons.favorite),
                selectedIcon: Icon(Icons.favorite_border),
                label: Text('Home'),
              ),
              NavigationRailDestination(
                icon: Icon(Icons.bookmark),
                selectedIcon: Icon(Icons.bookmark_border),
                label: Text('Bookmark'),
              ),
            ],
          ),
     
          Expanded(
            child: _childern[_selectedIndex],
          )
        ],
      ),
    );
  }
}