[英]Change the background color of a single Spinner Item in Android upon Item's Selection
[英]How to change card color upon selection of an item in Flutter?
我在从 model 获取的 gridView 中列出了多张卡。 我想在选择卡片时更改特定卡片的背景颜色。 也就是说,当我触摸卡片时,我想让那张卡片的颜色改变,如果我 select 另一张卡片,我想让第一张卡片的颜色 go 恢复到原来的颜色,并希望第二张卡片的颜色改变。 我尝试了各种方法,但无法做到。
网格视图:
Widget build(BuildContext context) {
final petTypes = widget.pet.types();
var petKeys = petTypes.keys.toList();
return Scaffold(
appBar: AppBar(
title: Text('Add pets - Type'),
backgroundColor: Color.fromRGBO(101, 69, 112, 1.0),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Expanded(
child: GridView.count(
crossAxisCount: 2,
scrollDirection: Axis.vertical,
primary: false,
children: List.generate(petTypes.length, (index) {
return GestureDetector(
child: Card(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
petTypes[petKeys[index]],
Text(petKeys[index]),
],
),
// onPressed: () async {
// widget.pet.type = petKeys[index];
// },
),
onTap: (){
setState(() {
widget.pet.type = petKeys[index];
});
}
);
}),
),
),
model:
Map<String, Image> types() => {
"Dog":
Image(image: AssetImage('Assets/images/dog-type.png'), width: 70),
"Cat":
Image(image:AssetImage('Assets/images/cat-type.png'), width: 70),
"Bird":
Image(image:AssetImage('Assets/images/bird-type.png'), width: 70),
"Rabbit":
Image(image:AssetImage('Assets/images/rabbit-type.png'), width: 70),
"Hamster":
Image(image:AssetImage('Assets/images/hamster-type.png'), width: 70),
"Fish":
Image(image:AssetImage('Assets/images/fish-tank.png'), width: 70),
...
};
在 state class 上创建一个可为空的 int 并基于它传递颜色,并在onTap:
like
int? selectedIndex;
@override
Widget build(BuildContext context) {
//...
GestureDetector(
child: Card(
color: selectedIndex != null ? Colors.green : null,
),
onTap: () {
setState(() {
selectedIndex = index;
});
},
);
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