类型'List<Widget>‘不是类型'Widget’的子类型
类型'List<Widget>‘不是类型'Widget’的子类型
提问于 2021-08-12 21:12:02
“我是flutter dev的初学者，正在尝试实现屏幕，但似乎无法理解抛出的错误下面的代码应该显示一个入门屏幕，但它似乎抛出了一个关于标题的模拟器错误，并且似乎在web上找不到任何解决方案任何帮助？”
class OnBoardingScreen extends StatefulWidget {
@override
_OnBoardingScreenState createState() => _OnBoardingScreenState();
}
class _OnBoardingScreenState extends State<OnBoardingScreen> {
final int _numPages = 5;
final PageController _pageController = PageController(initialPage: 0);
int _currentPage =0;
void _onIntroEnd(context) {
Navigator.of(context).push(MaterialPageRoute(builder: (_) => SignUpScreen()));
}
void _onIntroSkip(context) {
Navigator.of(context).push(MaterialPageRoute(builder: (_) => LoginScreen()));
}
_buildPageIndicator(){
List<Widget> list =[];
for (int i=0;i<_numPages;i++){
list.add(i == _currentPage ? _indicator(true) : _indicator(false) );
}
return list;
}
_indicator (bool isActive){
return AnimatedContainer(duration: Duration(milliseconds: 150),
margin: EdgeInsets.symmetric(horizontal: 8.0),
height: 8.0,
width: isActive ? 24.0 : 16.0,
decoration: BoxDecoration(color: isActive ? Colors.white:Color(0xF385AD5),
borderRadius:BorderRadius.all(Radius.circular(12))
),
);
}
@override
Widget build(BuildContext context) {
return Scaffold(
body: AnnotatedRegion(
value: null,
child: Container(
decoration: BoxDecoration(
gradient:LinearGradient(
begin: Alignment.topCenter,
end: Alignment.bottomCenter,
stops: [0.1,0.4,0.7,0.9],
colors: [
Color(0xF3C5DD7),
Color(0xF092458),
Color(0xF1B5695),
Color(0xF4664A0)
]
)
),
child: Padding(
padding: const EdgeInsets.symmetric(vertical: 40),
child: Column(
crossAxisAlignment: CrossAxisAlignment.stretch,
children: [
Container(
alignment: Alignment.centerRight,
child: TextButton(
onPressed: (){
_onIntroSkip(context);
},
child: Text(
'Skip',
style: TextStyle(
color: Colors.white,
fontSize: 20.0,
),
),
),
),
Container(
height: 600.0,
child: PageView(
physics :ClampingScrollPhysics(),
controller: _pageController,
onPageChanged: (int page){
setState(() {
_currentPage =page;
});
},
children: [
Padding(
padding: EdgeInsets.all(40.0),
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: [
Center(
child: Image(
image: AssetImage('assets/rooms.webp'
),
height: 300,
width: 300,
),
),
SizedBox(
height: 30.0,
),
Text('Lorem Ipsum',
style: TextStyle(
fontWeight: FontWeight.w800
),
),
SizedBox(height: 15.0,),
Text('Lorem IpSsum',style:TextStyle(
fontWeight: FontWeight.w300
),
)
],
),
),
Padding(
padding: EdgeInsets.all(40.0),
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: [
Center(
child: Image(
image: AssetImage('assets/thoughts.webp'
),
height: 300,
width: 300,
),
),
SizedBox(
height: 30.0,
),
Text('Lorem Ipsum',
style: TextStyle(
fontWeight: FontWeight.w800
),
),
SizedBox(height: 15.0,),
Text('Lorem IpSsum',style:TextStyle(
fontWeight: FontWeight.w300
),
)
],
),
),
Padding(
padding: EdgeInsets.all(40.0),
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: [
Center(
child: Image(
image: AssetImage('group.jpg'
),
height: 300,
width: 300,
),
),
SizedBox(
height: 30.0,
),
Text('Lorem Ipsum',
style: TextStyle(
fontWeight: FontWeight.w800
),
),
SizedBox(height: 15.0,),
Text('Lorem IpSsum',style:TextStyle(
fontWeight: FontWeight.w300
),
)
],
),
),
],
),
),
Row(
mainAxisAlignment:MainAxisAlignment.center ,children: [
_buildPageIndicator() ,
],
),
_currentPage != _numPages - 1 ?
Expanded(
child: Align(
alignment: FractionalOffset.bottomRight,
child: TextButton(
onPressed: () {
_pageController.nextPage(duration: Duration(milliseconds: 500), curve: Curves.ease);
}, child:Row(
mainAxisAlignment: MainAxisAlignment.center,
mainAxisSize: MainAxisSize.min,
children: [
Text('Next',style: TextStyle(color: Colors.white,
fontSize: 22.0),),
SizedBox(
width: 10.0,
),
Icon(
Icons.arrow_forward,
color: Colors.white,
size: 30,
)
],
),
),
),
)
:
Text("")
],
),
),
),
),
bottomSheet:_currentPage == _numPages -1 ? Container(
height: 100.0,
width: double.infinity,
color: Colors.white,
child: GestureDetector(
onTap: (){
_onIntroEnd(context);
},
child: Center(
child: Padding(padding: EdgeInsets.only(bottom: 30.0),child:
Text(
'Get Started',
style: TextStyle(
color: Color(0xF3C5DD7),
fontSize: 20.0,
fontWeight: FontWeight.bold,
),
)),
),
),
) :
Text(''),
);
}
}‘这应该显示一个入职屏幕，但抛出一个错误。这与附加的图像一起显示。’
回答 2
Stack Overflow用户
发布于 2021-08-12 21:15:07
更改代码的这些部分，使其如下所示：
List<Widget> _buildPageIndicator(){
List<Widget> list =[];
for (int i=0;i<_numPages;i++){
list.add(i == _currentPage ? _indicator(true) : _indicator(false) );
}
return list;
}
.
.
.
.
Row(
mainAxisAlignment:MainAxisAlignment.center,
children: _buildPageIndicator() ,
),Stack Overflow用户
发布于 2021-08-12 21:40:53
替换代码的这一部分：
...
Row(
mainAxisAlignment:MainAxisAlignment.center ,children: [
_buildPageIndicator() ,
],
),
...使用
...
Row(
mainAxisAlignment:MainAxisAlignment.center, children: _buildPageIndicator(),
),
...或使用
...
Row(
mainAxisAlignment:MainAxisAlignment.center ,children: [
..._buildPageIndicator(),
],
),
...页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/68764220
复制相关文章
相似问题
腾讯云开发者
