TabBar_code.dart

import 'package:flutter/material.dart';

void main(){runApp(MyApp());}
class MyApp extends StatelessWidget{
  @override
  Widget build(BuildContext context) { 
   /* final _tabs = <Tab>[
      Tab(icon: Icon(Icons.mark_chat_unread_rounded), text='Chat'),
      Tab(icon: Icon(Icons.email), text='Email'),
      Tab(icon: Icon(Icons.add_box_rounded), text='Social'),
    ];*/
    
    return MaterialApp(
      debugShowCheckedModeBanner:false,
      title:"ChatApp",
      theme:ThemeData(
        primaryColor:Colors.white,
    ),
    home:DefaultTabController(
      length:3,
      child:Scaffold(
    appBar: AppBar(
      leading:null,
      bottom:TabBar(
        labelPadding: EdgeInsets.all(0),
        tabs:[
          Tab(icon: Icon(Icons.mark_chat_unread_rounded), 
              text:'Chat',
             ),
          Tab(icon: Icon(Icons.email), text:'Email'),
          Tab(icon: Icon(Icons.add_box_rounded), text:'Social'),
        ],
    ))),) 
    );
  }
}