Alexandru Buruiana
Alexandru Buruiana

Reputation: 137

Flutter change what it is displayed in a tab

I curently have a problem displaying different widgets for each tab that I choose.

Is there any way I can change the text or anything else when I tap another tabbar?

I tried using tabNames[index] and index inside the switch, and I created a different case for each page, but it isn't working. I have multiple widgets that I want to display in each tab, depending on which tab I tap.

import 'package:flutter/material.dart';

void main() {
  runApp(new MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
      title: 'Navigation Example',
      home: new MyHomePage(),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key}) : super(key: key);

  @override
  _MyHomePageState createState() => new _MyHomePageState();
}

const List<String> tabNames = const<String>[
  'foo', 'bar', 'baz', 'quox', 'quuz', 'corge', 'grault', 'garply', 'waldo'
];

class _MyHomePageState extends State<MyHomePage> {

  int _screen = 0;

  @override
  Widget build(BuildContext context) {
    return new DefaultTabController(
      length: tabNames.length,
      child: new Scaffold(
        appBar: new AppBar(
          title: new Text('Navigation example'),
        ),
        body: new TabBarView(
          children: new List<Widget>.generate(tabNames.length, (int index) {
            switch (_screen) {
              case 0: return new Center(
                child: new Text('First screen, ${tabNames[index]}'),
              );
              case 1: return new Center(
                child: new Text('Second screen'),
              );
            }
          }),
        ),
        bottomNavigationBar: new Column(
          mainAxisSize: MainAxisSize.min,
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: [
            new AnimatedCrossFade(
              firstChild: new Material(
                color: Theme
                  .of(context)
                  .primaryColor,
                child: new TabBar(
                  isScrollable: true,
                  tabs: new List.generate(tabNames.length, (index) {
                    return new Tab(text: tabNames[index].toUpperCase());
                  }),
                ),
              ),
              secondChild: new Container(),
              crossFadeState: _screen == 0
                              ? CrossFadeState.showFirst
                              : CrossFadeState.showSecond,
              duration: const Duration(milliseconds: 300),
            ),
            new BottomNavigationBar(
              currentIndex: _screen,
              onTap: (int index) {
                setState(() {
                  _screen = index;
                });
              },
              items: [
                new BottomNavigationBarItem(
                  icon: new Icon(Icons.airplanemode_active),
                  title: new Text('Airplane'),
                ),
                new BottomNavigationBarItem(
                  icon: new Icon(Icons.motorcycle),
                  title: new Text('Motorcycle'),
                ),
              ],
            ),
          ],
        ),
      ),
    );
  }
}

Upvotes: 0

Views: 353

Answers (1)

Andrea Costanzo
Andrea Costanzo

Reputation: 2215

I don't think that the way you are passing the list of widgets to the TabBarView is appropriated. Do not use List.generate: instead, try wrapping your widgets like this:

body: TabBarView(
         children: [
          Center(child: Text('First screen')),
          Center(child: Text('Second screen')),
         ]
),

The tab controller dynamically handles the change of pages without the need to put a switch case to select the screen.

Upvotes: 1

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