清空路由 路由替换 返回到根路由

import ‘../../home.dart‘;

  Navigator.of(context).pushAndRemoveUntil(
      new MaterialPageRoute(
          builder: (context) => Home(index: 2)
      ), (route) => route == null);

Home.dart

class Home extends StatefulWidget{
  final index;
  Home({Key key,this.index = 0});
  _HomeState createState() => _HomeState(this.index);
}

class _HomeState extends State {
  var _currentIndex;
  var tabs = [Index(), ClassIf(), My()];
  _HomeState(index) {
    _currentIndex = index;
  }
}