title: Tabbar view for my flutter app is not working
body: <p>This is my code. Changing tabbar view contents is not changing the contents.</p>
  
  <p>I've tried changing the children of tabbar view to text but still no effect</p>
  
  <pre><code>import 'package:flutter/material.dart';
  
  void main() =&gt; runApp(MyApp());
  
  class MyApp extends StatelessWidget {
    @override
    Widget build(BuildContext context) {
      return MaterialApp(
        title: 'Material App',
        home: Scaffold(
          backgroundColor: Colors.white,
          body: SafeArea(
            child: Column(
              children: &lt;Widget&gt;[
                Container(
                  height: 60,
                  width: 500,
                  color: Colors.teal,
                  margin: EdgeInsets.fromLTRB(0, 0, 0, 0),
                  padding: EdgeInsets.fromLTRB(10, 0, 0, 0),
                  child: Text(
                    'Choose Your Topic',
                    textAlign: TextAlign.left,
                    style: TextStyle(
                      fontFamily: 'BalooBhaina2-Regular',
                      fontWeight: FontWeight.normal,
                      fontSize: 35,
                      letterSpacing: 0.5,
                      wordSpacing: 2.0,
                      shadows: [
                        Shadow(
                          blurRadius: 50.0,
                          color: Colors.black,
                          offset: Offset(5.0, 5.0),
                        ),
                      ],
                    ),
                  ),
                ),
                Container(
                  height: 50,
                  width: 800,
                  margin: EdgeInsets.fromLTRB(0, 0, 0, 5),
                  child: DefaultTabController(
                    length: 4,
                    child: Scaffold(
                      appBar: AppBar(
                        bottom: TabBar(tabs: [
                          Tab(icon: Icon(Icons.touch_app)),
                          Tab(icon: Icon(Icons.directions_bike)),
                          Tab(icon: Icon(Icons.movie)),
                          Tab(icon: Icon(Icons.music_video)),
                        ]),
                      ),
                      body: TabBarView(
                        children: [
                          Icon(Icons.touch_app),
                          Icon(Icons.directions_bike),
                          Icon(Icons.movie),
                          Icon(Icons.music_video),
                        ],
                      ),
                    ),
                  ),
                ),
              ],
            ),
          ),
        ),
      );
    }
  }
  </code></pre>