flutter - pageview flutter如何跳转到另一个页面

Question

您好，如果我按下第一个页面选项卡上的按钮，我试图跳转到第二个页面选项卡。目前我只知道我的第二页小部件的调用路由但 bottomnavbar 不存在......我不知道如何从我的第一页选项卡调用我的父小部件以跳转到第二页选项卡。

  class Parent  {

  int bottomSelectedIndex = 0;

  List<BottomNavigationBarItem> buildBottomNavBarItems() {
    return [
      BottomNavigationBarItem(
          icon: new Icon(Icons.home),
          title: new Text('First')
      ),
      BottomNavigationBarItem(
        icon: new Icon(Icons.search),
        title: new Text('Second'),
      ),

    ];
  }

  PageController pageController = PageController(
    initialPage: 0,
    keepPage: true,
  );

  Widget buildPageView() {
    return PageView(
      controller: pageController,
      onPageChanged: (index) {
        pageChanged(index);
      },
      children: <Widget>[
        First(),
        Second(),

      ],
    );
  }

  @override
  void initState() {
    super.initState();
  }

  void pageChanged(int index) {
    setState(() {
      bottomSelectedIndex = index;
    });
  }

  void bottomTapped(int index) {
    setState(() {
      bottomSelectedIndex = index;
      pageController.animateToPage(index, duration: Duration(milliseconds: 500), curve: Curves.ease);
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: buildPageView(),
      bottomNavigationBar: BottomNavigationBar(
        currentIndex: bottomSelectedIndex,
        onTap: (index) {
          bottomTapped(index);
        },
        items: buildBottomNavBarItems(),
      ),
    );
  }
  }

---

  class first {
        return Container(
    // here a pressbutton for jump to the second widget
        );

    }

----------------------------------------------------------


    class second
        return Container(

        );
    }

Answer 1

你可以使用这个:

void onAddButtonTapped(int index) {

  // use this to animate to the page
  pageController.animateToPage(index);

  // or this to jump to it without animating
  pageController.jumpToPage(index);
}

将函数作为参数传递:

class first {
  final void Function(int) onAddButtonTapped;

        return Container(
// call it here onAddButtonTapped(2);
        );

    }

class Second {
  final void Function(int) onAddButtonTapped;

        return Container(
        );

    }

children: <Widget>[
        First(onAddButtonTapped),
        Second(onAddButtonTapped),
      ],