flutter - CupertinoTabBar 导航

Question

对于第一个标签栏:我在 DispayMoreScreen 上有一个注销按钮。对于注销按钮操作，应用会正确导航到应用的根目录。

Navigator.of(context).pushReplacementNamed('/')

带工作导航的标签栏:

@override
  Widget build(BuildContext context) {    
        return new Scaffold(
            bottomNavigationBar: new Material(
                color: Colors.white,
                child: new TabBar(controller: controller, labelColor: Colors.blue[900], tabs: <Tab>[
                  new Tab(icon: new Icon(Icons.local_shipping, color: Colors.blue[900], size: 30.0), text: 'A'),
                  new Tab(icon: new Icon(Icons.insert_drive_file, color: Colors.blue[900], size: 30.0), text: 'B'),
                  new Tab(icon: new Icon(Icons.more_horiz, color: Colors.blue[900], size: 30.0), text: 'C'),
                ])),
            body: new TabBarView(controller: controller, children: <Widget>[
              new ShipmentScreen.ShipmentTab(),
              new InvoiceScreen.InvoiceTab(),
              new DisplayMoreScreen.MoreTab(),
            ])
        );
  }

但是当我实现 CupertinoTabBar 时，注销后应用程序保持在同一屏幕上。

  @override
  Widget build(BuildContext context) {
    return new CupertinoTabScaffold(
      tabBar: new CupertinoTabBar(
        backgroundColor: Colors.white,
        activeColor: Colors.blue[900],
        items: [
          new BottomNavigationBarItem(
            icon: new Icon(Icons.local_shipping),
            title: new Text("A")
          ),
          new BottomNavigationBarItem(
            icon: new Icon(Icons.insert_drive_file),
            title: new Text("B")
          ),
          new BottomNavigationBarItem(
            icon: new Icon(Icons.more_horiz),
            title: new Text("C")
          )
        ]
      ),
      tabBuilder: (BuildContext context, int index) {
        return new CupertinoTabView(
          builder: (BuildContext context) {
            switch(index) {
              case 0:
                return new ShipmentScreen.ShipmentTab();
              case 1:
                return new InvoiceScreen.InvoiceTab();
              case 2:
                return new DisplayMoreScreen.MoreTab();
            }
          },
        );
      }

Answer 1

当你点击标签时，你必须 setState():

“这个 [StatelessWidget] 本身不存储事件选项卡。您必须监听 [onTap] 回调并使用新的 [currentIndex] 调用 setState 以反射(reflect)新的选择。”

我还认为构建器中的“switch (index)”应该改为切换到“currentIndex”变量。