错误：无法将参数类型“Null Function(int)”分配给参数类型“dynamic Function(int, CarouselPageChangedReason)”

如何解决错误：无法将参数类型“Null Function(int)”分配给参数类型“dynamic Function(int, CarouselPageChangedReason)”

我也使用轮播幻灯片插件创建轮播幻灯片图像，但是当我初始化“int”变量时 _current = 0;我创建了一个设置状态来将变量分配给它，它给了我一个错误。 "Null function(int)' 不能分配给参数类型 'dynamic Function(int,CarouselPageChangedReason)'"

class HomePage 扩展了 StatefulWidget { 静态字符串页面 = 'home_Page';

  @override
  _HomePageState createState() => _HomePageState();
}

class _HomePageState extends State<HomePage> {
  int _current = 0;

  List imgList = [
    'assets/images/deal1.jpg','assets/images/deal4.jpg','assets/images/deal2.jpg','assets/images/deal3.png',];

  @override
  Widget build(BuildContext context) {
    SizeConfig().init(context);
    return Scaffold(
      appBar: buildAppBar,drawer: Drawer(
        child: DrawerPage(),),body: Container(
        margin: EdgeInsets.only(left: 14),child: Container(
          height: getProportionateScreenHeight(820),child: ListView(
            children: [
              Column(
                crossAxisAlignment: CrossAxisAlignment.start,children: [
                  welcomeHeader(),SizedBox(height: getProportionateScreenHeight(10)),SearchField(),SizedBox(height: getProportionateScreenHeight(20)),categorySectionTitle(),SizedBox(height: getProportionateScreenWidth(5)),categoryListTiles(),popularFoodSectionTiles(),Column(
                    mainAxisAlignment: MainAxisAlignment.center,crossAxisAlignment: CrossAxisAlignment.center,children: [
                      CarouselSlider(
                        options: CarouselOptions(
                          height: 100,initialPage: 0,onPageChanged: (index) {
                            setState(() {
                              _current = index;
                            });
                          },enter code here
                        items: [],],restaurantSplendorTiles(),RestaurantCat(),);
  }
}

这是错误的代码行：

onPageChanged: (index) {
                            setState(() {
                              _current = index;
                            });
                          }

,

请帮帮我... :(

解决方法

看起来您需要在 onPageChanged 函数中接受另一个参数。这样的事情应该工作......

onPageChanged: (index,_) {
  setState(() {
    _current = index;
  });
}

,

我找到了答案，而不是 ;

onPageChanged: (index) {
                            setState(() {
                              _current = index;
                            });
                          }

应该是;

onPageChanged: (index,reason) {
                            setState(() {
                              _current = index;
                            });
                          }