如何在颤振中设置初始选项卡

Question

I want that whenever I run my application, it should be moved to Tab A, but by default it is moving to first tab, which is named tab B.

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: DefaultTabController(
          length: 2,
          child: Scaffold(
            appBar: AppBar(
              title: Text("Tab Bar"),
              bottom:
                  TabBar(tabs: [Tab(child: Text('B')), Tab(child: Text('A'))]),
            ),
            body: TabBarView(children: [
              Center(
                child: Text("this is to be second tab"),
              ),
              Center(
                child: Text("this is to be first tab"),
              ),
            ]),
          )),
    );
  }
}

Answer 1

The DefaultTabController has an initialIndex property which is set to 0 by default.

In your case, since you have two Tab s, you would need to set the initialIndex property to 1 .

I added a demo using your code as an example:

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: DefaultTabController(
          length: 2,
          // set initial index to 1
          initialIndex: 1,
          child: Scaffold(
            appBar: AppBar(
              title: Text("Tab Bar"),
              bottom:
                  TabBar(tabs: [Tab(child: Text('B')), Tab(child: Text('A'))]),
            ),
            body: TabBarView(children: [
              Center(
                child: Text("this is to be second tab"),
              ),
              Center(
                child: Text("this is to be first tab"),
              ),
            ]),
          )),
    );
  }
}