Flutter 类型 'List<dynamic>' 不是类型 'list<Widget>' 的子类型
Flutter type 'List<dynamic>' is not a subtype of type 'list<Widget>'
我正在尝试用带有图像的卡片制作列表,想法是这些卡片在未来通过 API 请求动态生成,但现在我只想从图像开始,但是当我 运行 我有以下错误:
类型 'List ' 不是类型 'list '
的子类型
怎么解决啊,请大家帮忙
我的代码在一个名为:
的文件中
requests.dart
这是我的代码:
import 'package:flutter/material.dart';
class MyApp extends StatelessWidget {
// This widget is the root of your application.
@override
Widget build(BuildContext context) {
return new MaterialApp(
home:new MyCard()
);
}
}
class MyCard extends StatelessWidget{
List cards = new List.generate(20, (i)=>new CustomCard());
@override
Widget build(BuildContext context) {
return new Scaffold(
appBar: new AppBar(
title: new Text('Car Results'),
backgroundColor:new Color(0xFF673AB7),
),
body: new Container(
child: new ListView(
children: cards,
)
)
);
}
}
class CustomCard extends StatelessWidget {
@override
Widget build(BuildContext context) {
return new Card(
child: new Column(
children: <Widget>[
new Image.network('https://matwrites.com/wp-content/uploads/2018/03/Flutter.png'),
new Padding(
padding: new EdgeInsets.all(7.0),
child: new Row(
children: <Widget>[
new Padding(
padding: new EdgeInsets.all(7.0),
child: new Icon(Icons.thumb_up),
),
new Padding(
padding: new EdgeInsets.all(7.0),
child: new Text('Like',style: new TextStyle(fontSize: 18.0),),
),
new Padding(
padding: new EdgeInsets.all(7.0),
child: new Icon(Icons.comment),
),
new Padding(
padding: new EdgeInsets.all(7.0),
child: new Text('Comments',style: new TextStyle(fontSize: 18.0)),
)
],
)
)
],
),
);
}
}
改变
List cards = new List.generate(20, (i)=>new CustomCard());
到
final List<Widget> cards = List<Widget>.generate(20, (i)=>new CustomCard());
Children 不需要列表,甚至不需要动态类型。
我正在尝试用带有图像的卡片制作列表,想法是这些卡片在未来通过 API 请求动态生成,但现在我只想从图像开始,但是当我 运行 我有以下错误:
类型 'List ' 不是类型 'list '
的子类型怎么解决啊,请大家帮忙
我的代码在一个名为:
的文件中requests.dart
这是我的代码:
import 'package:flutter/material.dart';
class MyApp extends StatelessWidget {
// This widget is the root of your application.
@override
Widget build(BuildContext context) {
return new MaterialApp(
home:new MyCard()
);
}
}
class MyCard extends StatelessWidget{
List cards = new List.generate(20, (i)=>new CustomCard());
@override
Widget build(BuildContext context) {
return new Scaffold(
appBar: new AppBar(
title: new Text('Car Results'),
backgroundColor:new Color(0xFF673AB7),
),
body: new Container(
child: new ListView(
children: cards,
)
)
);
}
}
class CustomCard extends StatelessWidget {
@override
Widget build(BuildContext context) {
return new Card(
child: new Column(
children: <Widget>[
new Image.network('https://matwrites.com/wp-content/uploads/2018/03/Flutter.png'),
new Padding(
padding: new EdgeInsets.all(7.0),
child: new Row(
children: <Widget>[
new Padding(
padding: new EdgeInsets.all(7.0),
child: new Icon(Icons.thumb_up),
),
new Padding(
padding: new EdgeInsets.all(7.0),
child: new Text('Like',style: new TextStyle(fontSize: 18.0),),
),
new Padding(
padding: new EdgeInsets.all(7.0),
child: new Icon(Icons.comment),
),
new Padding(
padding: new EdgeInsets.all(7.0),
child: new Text('Comments',style: new TextStyle(fontSize: 18.0)),
)
],
)
)
],
),
);
}
}
改变
List cards = new List.generate(20, (i)=>new CustomCard());
到
final List<Widget> cards = List<Widget>.generate(20, (i)=>new CustomCard());
Children 不需要列表,甚至不需要动态类型。