title: TabBarView content not updating on setstate
body: <p><a href="https://youtu.be/CZKILXh9PcA" rel="nofollow noreferrer">Check video for more clearifacation</a>
  <br>
  <a href="https://gitlab.com/midhilajcom5/flutterTabBarView" rel="nofollow noreferrer">gitlab link</a>
  <br>My code</p>
  
  <pre><code>import 'package:flutter/material.dart';
  import 'package:flutter_app/Page.dart';
  
  import 'page1.dart';
  
  void main() =&gt; runApp(MyAppPages());
  
  class MyApp extends StatefulWidget {
    String message;
    MyApp(this.message) {}
    @override
    _MyAppState createState() =&gt; _MyAppState(message);
  }
  
  class _MyAppState extends State&lt;MyApp&gt; {
    String message;
    _MyAppState(this.message) {}
  
  
    @override
    Widget build(BuildContext context) {
      return Container(
        child: Center(
          child: Text(message),
        ),
  
      );
    }
  }
  
  class MyAppPages extends StatefulWidget {
    @override
    _MyAppPages createState() =&gt; _MyAppPages();
  }
  
  class _MyAppPages extends State&lt;MyAppPages&gt; {
    @override
    Widget build(BuildContext context) {
      return MaterialApp(
        home: DefaultTabController(
          length: 3,
          child: Scaffold(
            floatingActionButton: FloatingActionButton(
                child: Icon(Icons.add),
                onPressed: (){
  
             this.setState(() {
                ct+=1;
              print("ct $ct");
              });
            }),
            appBar: AppBar(
              bottom: TabBar(
                tabs: [
                  Tab(
                      child: GestureDetector(
                        child: Text("page1"),
                        onTap: () {
                        this.  setState(() {
                            ct += 1;
                          });
                          print("ct $ct");
                    },
                  )),
                  Tab(child: Text("page2")),
                  Tab(child: Text("page3"))
                ],
              ),
            ),
            body:
                TabBarView(children: [MyApp("sub_1_ct_$ct"),MyApp("sub_2_ct_$ct"), MyApp("sub_3_ct_$ct")]),
          ),
        ),
      );
    }
  
    int ct = 0;
  
  }
  </code></pre>
  
  <p><br><Br></p>
  
  <pre><code>import 'package:flutter/material.dart';
  
  import 'Page.dart';
  
  class Page1 extends StatefulWidget {
    List&lt;Page&gt; data;
    Page1({this.data,Key key}) : super(key: key);
  
    @override
    _Page1State createState() =&gt; _Page1State(data:data);
  }
  
  class _Page1State extends State&lt;Page1&gt; {
    List&lt;Page&gt; data;
    _Page1State({this.data}){
  
    }
    @override
    Widget build(BuildContext context) {
      return ListView.builder(
          itemCount: data.length,
          itemBuilder: (context,index){
        return Container(
          margin: EdgeInsets.all(10),
          child: Card(
            child: Padding(
              padding: const EdgeInsets.all(8.0),
              child: ListTile(
                title: Text(data[index].title),
              ),
            ),
          ),
        );
      });
    }
  }
  </code></pre>
  
  <p><br><br></p>
  
  <pre><code>class Page{
    String title;
    Page({this.title}){
  
    }
  }
  </code></pre>
  
  <p><br><br>  <a href="https://youtu.be/CZKILXh9PcA" rel="nofollow noreferrer">1</a>: <a href="https://youtu.be/CZKILXh9PcA" rel="nofollow noreferrer">https://youtu.be/CZKILXh9PcA</a></p>