Flutter 通过引用颤振中的另一个列表来过滤列表
我有两个列表,一个是存储汽车类别(如SUV、轿车、小型货车等)。 第二个列表存储了汽车的所有细节,它也包含了汽车类别 我使用嵌套的listview,其中第一个listview以垂直方式显示汽车类别,在它内部,我想以水平方式显示汽车属于同一类别的详细信息 下面是代码片段:Flutter 通过引用颤振中的另一个列表来过滤列表,flutter,dart,Flutter,Dart,我有两个列表,一个是存储汽车类别(如SUV、轿车、小型货车等)。 第二个列表存储了汽车的所有细节,它也包含了汽车类别 我使用嵌套的listview,其中第一个listview以垂直方式显示汽车类别,在它内部,我想以水平方式显示汽车属于同一类别的详细信息 下面是代码片段: ListView.builder( //This is First list with only Category name
ListView.builder( //This is First list with only Category name
shrinkWrap: true,
scrollDirection: Axis.vertical,
itemCount: categoriesOnlyList.length,
itemBuilder: (context, index1) {
return
Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: [
Padding(
padding: const EdgeInsets.all(8.0),
child: Container(
margin: EdgeInsets.only(left: 20),
child: Text(
categoriesOnlyList[index1].Name,
textAlign: TextAlign.start,
style: TextStyle(color: Colors.white70,
fontWeight: FontWeight.bold,
fontSize: 18),
),
),
),
Container(
height: 300,
decoration: BoxDecoration(
borderRadius: BorderRadius.circular(8),
),
child: ListView.builder( //This the Second List with all details.
shrinkWrap: true,
itemCount: categoryItemList.length,
scrollDirection: Axis.horizontal,
itemBuilder: (context,index){
return categoriesOnlyList[index1].Name==categoryItemList[index].CategoryName
&& categoryItemList[index].ID.startsWith("105")? // Here I'm applying condition
Padding(
padding: const EdgeInsets.all(20.0),
child: Padding(
padding: const EdgeInsets.all(8.0),
child: Text(categoryItemList[index].Name,style: TextStyle(color: Colors.white70),),
),
):Container();
}),
)
],
);
}),
这就是我想要实现的目标:
不知何故,我能够通过上面的代码实现这一点,但在水平滚动项目方面面临另一个问题,请在下面给出的链接上提问
.据我所知,这可能会解决您的问题:
class MyHomePage extends StatelessWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
final list = [
'BMW',
'Toyota',
'Testa',
'Ford',
'Fiat',
'BMW',
'Toyota',
'Testa',
'Ford',
'Fiat'
];
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(title: Text(title)),
body: ListView.builder(
itemCount: 20,
itemBuilder: (_, __) {
return SizedBox(
width: double.infinity,
height: 60,
child: ListView.builder(
scrollDirection: Axis.horizontal,
itemBuilder: (context, index) {
return Padding(
padding: const EdgeInsets.all(16),
child: Text(list[index]),
);
},
itemCount: list.length,
),
);
},
));
}
}
更新(1)
下面是显示这些组的完整颤振代码:
class Car {
final String company;
final String category;
Car(this.company, this.category);
}
class MyHomePage extends StatelessWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
final list = [
Car('Toyata', 'SUV'),
Car('BMW', 'SEDAN'),
Car('Tesla', 'SUV'),
Car('Toyata', 'SUV'),
Car('BMW', 'SEDAN'),
Car('Tesla', 'SUV'),
Car('Toyata', 'SUV'),
Car('BMW', 'SEDAN'),
Car('Tesla', 'SUV'),
Car('Toyata', 'SUV'),
Car('BMW', 'SEDAN'),
Car('Tesla', 'SUV'),
Car('Toyata', 'SUV'),
Car('BMW', 'SEDAN'),
Car('Tesla', 'SUV'),
Car('Toyata', 'SUV'),
Car('BMW', 'SEDAN'),
Car('Tesla', 'SUV'),
Car('Toyata', 'SUV'),
Car('BMW', 'SEDAN'),
Car('Tesla', 'SUV'),
Car('Toyata', 'SUV'),
Car('BMW', 'SEDAN'),
Car('Tesla', 'SUV'),
];
Map<String, List<Car>> groupedLists = {};
void groupMyList() {
list.forEach((car) {
if (groupedLists['${car.category}'] == null) {
groupedLists['${car.category}'] = <Car>[];
}
groupedLists['${car.category}'].add(car);
});
}
@override
Widget build(BuildContext context) {
groupMyList();
return Scaffold(
appBar: AppBar(title: Text(title)),
body: ListView(
children: [
for (var entry in groupedLists.entries)
SizedBox(
width: double.infinity,
height: 60,
child: ListView.builder(
itemCount: entry.value.length,
scrollDirection: Axis.horizontal,
itemBuilder: (context, index) {
return Padding(
padding: const EdgeInsets.all(16),
child: Text(entry.value[index].company),
);
},
),
),
],
),
);
}
}
等级车{
最终字符串公司;
最终字符串类别;
汽车(本公司、本类别);
}
类MyHomePage扩展了无状态小部件{
MyHomePage({Key,this.title}):超级(Key:Key);
最后的字符串标题;
最终名单=[
汽车(“Toyata”、“SUV”),
汽车(“宝马”、“轿车”),
汽车(“特斯拉”、“SUV”),
汽车(“Toyata”、“SUV”),
汽车(“宝马”、“轿车”),
汽车(“特斯拉”、“SUV”),
汽车(“Toyata”、“SUV”),
汽车(“宝马”、“轿车”),
汽车(“特斯拉”、“SUV”),
汽车(“Toyata”、“SUV”),
汽车(“宝马”、“轿车”),
汽车(“特斯拉”、“SUV”),
汽车(“Toyata”、“SUV”),
汽车(“宝马”、“轿车”),
汽车(“特斯拉”、“SUV”),
汽车(“Toyata”、“SUV”),
汽车(“宝马”、“轿车”),
汽车(“特斯拉”、“SUV”),
汽车(“Toyata”、“SUV”),
汽车(“宝马”、“轿车”),
汽车(“特斯拉”、“SUV”),
汽车(“Toyata”、“SUV”),
汽车(“宝马”、“轿车”),
汽车(“特斯拉”、“SUV”),
];
映射GroupedList={};
void groupMyList(){
列表。每辆车((车){
if(GroupedList['${car.category}']==null){
GroupedList['${car.category}']=[];
}
GroupedList['${car.category}'].add(car);
});
}
@凌驾
小部件构建(构建上下文){
groupMyList();
返回脚手架(
appBar:appBar(标题:文本(标题)),
正文:ListView(
儿童:[
for(GroupedList.entries中的var条目)
大小盒子(
宽度:double.infinity,
身高:60,
子项:ListView.builder(
itemCount:entry.value.length,
滚动方向:轴水平,
itemBuilder:(上下文,索引){
返回填充(
填充:常量边集。全部(16),
子项:文本(entry.value[index].company),
);
},
),
),
],
),
);
}
}
事实上这不是我想要的,您还没有比较列表。它们是两个列表。我的主要问题是筛选列表。你的意思是这个问题基本上与飞镖而非颤振有关,并且你有一个不同类别的汽车列表,你想对它们进行筛选/分组吗?是的,我完全想要相同的。如果答案正确,请查看更新的答案=D
{
SUV: [Instance of 'Car', Instance of 'Car'],
SEDAN: [Instance of 'Car']
}
class Car {
final String company;
final String category;
Car(this.company, this.category);
}
class MyHomePage extends StatelessWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
final list = [
Car('Toyata', 'SUV'),
Car('BMW', 'SEDAN'),
Car('Tesla', 'SUV'),
Car('Toyata', 'SUV'),
Car('BMW', 'SEDAN'),
Car('Tesla', 'SUV'),
Car('Toyata', 'SUV'),
Car('BMW', 'SEDAN'),
Car('Tesla', 'SUV'),
Car('Toyata', 'SUV'),
Car('BMW', 'SEDAN'),
Car('Tesla', 'SUV'),
Car('Toyata', 'SUV'),
Car('BMW', 'SEDAN'),
Car('Tesla', 'SUV'),
Car('Toyata', 'SUV'),
Car('BMW', 'SEDAN'),
Car('Tesla', 'SUV'),
Car('Toyata', 'SUV'),
Car('BMW', 'SEDAN'),
Car('Tesla', 'SUV'),
Car('Toyata', 'SUV'),
Car('BMW', 'SEDAN'),
Car('Tesla', 'SUV'),
];
Map<String, List<Car>> groupedLists = {};
void groupMyList() {
list.forEach((car) {
if (groupedLists['${car.category}'] == null) {
groupedLists['${car.category}'] = <Car>[];
}
groupedLists['${car.category}'].add(car);
});
}
@override
Widget build(BuildContext context) {
groupMyList();
return Scaffold(
appBar: AppBar(title: Text(title)),
body: ListView(
children: [
for (var entry in groupedLists.entries)
SizedBox(
width: double.infinity,
height: 60,
child: ListView.builder(
itemCount: entry.value.length,
scrollDirection: Axis.horizontal,
itemBuilder: (context, index) {
return Padding(
padding: const EdgeInsets.all(16),
child: Text(entry.value[index].company),
);
},
),
),
],
),
);
}
}