如何禁用tabbar中的特定选项卡，以便能够单击？

Question

有没有办法禁用标签栏中的特定选项卡？除非再次启用它，否则无法单击它？任何帮助表示赞赏，谢谢！

编辑：带吸收/忽略指针的代码不起作用：

class MyTabbedPage extends StatefulWidget {
  const MyTabbedPage({Key key}) : super(key: key);
  @override
  _MyTabbedPageState createState() => new _MyTabbedPageState();
}

class _MyTabbedPageState extends State<MyTabbedPage>
    with SingleTickerProviderStateMixin {
  final List<Tab> myTabs = <Widget>[
Tab(text: 'LEFT'),
    AbsorbPointer(
child: Tab(text: 'RIGHT')), //not working
  ];

  TabController _tabController;

  @override
  void initState() {
    super.initState();
    _tabController = new TabController(vsync: this, length: myTabs.length);
  }

  @override
  void dispose() {
    _tabController.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return new Scaffold(
      appBar: new AppBar(
        bottom: new TabBar(
          controller: _tabController,
          tabs: myTabs,
        ),
      ),
      body: new TabBarView(
        controller: _tabController,
        children: myTabs.map((Tab tab) {
          return new Center(child: new Text(tab.text));
        }).toList(),
      ),
    );
  }
}

Answer 1

干得好：

添加列表以禁用哪个选项卡

List<bool> _isDisabled = [false, true];

添加一个监听器到_tabController

_tabController.addListener(onTap);

onTap()方法。如果选中的选项卡被禁用，我们将恢复到之前选择的选项卡。

onTap() {
  if (_isDisabled[_tabController.index]) {
    int index = _tabController.previousIndex;
    setState(() {
      _tabController.index = index;
    });
  }
}

以下是完整代码：

import 'package:flutter/material.dart';

class MyTabbedPage extends StatefulWidget {
  const MyTabbedPage({Key key}) : super(key: key);
  @override
  _MyTabbedPageState createState() => _MyTabbedPageState();
}

class _MyTabbedPageState extends State<MyTabbedPage>
    with SingleTickerProviderStateMixin {
  List<bool> _isDisabled = [false, true];

  final List<Tab> myTabs = <Tab>[
    Tab(text: 'LEFT'),
    Tab(text: 'RIGHT'),
  ];

  TabController _tabController;

  onTap() {
    if (_isDisabled[_tabController.index]) {
      int index = _tabController.previousIndex;
      setState(() {
        _tabController.index = index;
      });
    }
  }

  @override
   void initState() {
    super.initState();
    _tabController = TabController(vsync: this, length: myTabs.length);
    _tabController.addListener(onTap);
  }

  @override
    void dispose() {
    _tabController.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        bottom: TabBar(
          controller: _tabController,
          tabs: myTabs,
        ),
      ),
      body: TabBarView(
        controller: _tabController,
        children: myTabs.map((Tab tab) {
          return Center(child: new Text(tab.text));
        }).toList(),
      ),
    );
  }
}

Answer 2

TabBar(
          tabs: [
            Tab(icon: Icon(Icons.directions_car)), //enabled
            Tab(icon: Icon(Icons.directions_transit), onTap: null), //disabled
            Tab(icon: Icon(Icons.directions_bike)),
          ],
        ),