切换按钮在颤动状态下不切换 [英] Toggle Button not toggling in Flutter
本文介绍了切换按钮在颤动状态下不切换的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我已经创建了一个带有ToggleButton的GridList,但当我尝试在彼此之间切换按钮时,什么也没有发生。有什么主意吗?我有一个列表is Selected,我在setState中调用了它。布局很好,但我一使用GridView,它似乎就更改了setState。
class Backgrounds extends StatefulWidget {
@override
_BackgroundsState createState() => _BackgroundsState();
}
class _BackgroundsState extends State<Backgrounds> {
List<bool> isSelected;
void initState() {
isSelected = [true, false, false, false, false, false, false, false, false];
super.initState();
}
@override
Widget build(BuildContext context) {
var counter = 0;
return GridView.count(
padding: EdgeInsets.all(12),
crossAxisCount: 3,
mainAxisSpacing: 0,
crossAxisSpacing: 0,
children: [
Image.asset('images/image1.png'),
Image.asset('images/image2.png'),
Image.asset('images/image3.png'),
Image.asset('images/image4.png'),
Image.asset('images/image5.png'),
Image.asset('images/image5.png'),
Image.asset('images/image6.png'),
Image.asset('images/image7.png'),
Image.asset('images/image8.png')
].asMap().entries.map((widget) {
final index = ++counter - 1;
return ToggleButtons(
onPressed: (int index) {
print('selected');
setState(() {
// isSelected[index] = !isSelected[index];
for (int i = 1; i < isSelected.length; i++) {
isSelected[i] = i == index;
}
});
},
isSelected: [isSelected[index]],
// isSelected: (isSelected),
selectedBorderColor: Color(0xff2244C7),
borderColor: Colors.transparent,
borderWidth: 3,
borderRadius: BorderRadius.all(Radius.circular(8),
),
children: [widget.value],
);
}).toList());
}
}
推荐答案
问题出在切换按钮的‘onPressed()’函数中。因为网格视图的列表是由映射生成的,所以每次切换按钮子列表大小为1时,‘OnPressed()’中的索引参数将始终给出值0。我建议在map中使用‘widget.key’,因为这会给出子窗口小部件的正确索引。因此,网格视图代码应为
return GridView.count(
padding: EdgeInsets.all(12),
crossAxisCount: 3,
mainAxisSpacing: 0,
crossAxisSpacing: 0,
children: [
Image.asset('images/image1.png'),
Image.asset('images/image2.png'),
Image.asset('images/image3.png'),
Image.asset('images/image4.png'),
Image.asset('images/image5.png'),
Image.asset('images/image5.png'),
Image.asset('images/image6.png'),
Image.asset('images/image7.png'),
Image.asset('images/image8.png')
].asMap().entries.map((widget) {
final index = ++counter - 1;
return ToggleButtons(
onPressed: (_) {
print('selected');
setState(() {
for (int i = 0; i < isSelected.length; i++) {
// isSelected[index] = !isSelected[index];
isSelected[i] = i == widget.key;
}
});
},
isSelected: [isSelected[widget.key]],
// isSelected: (isSelected),
selectedBorderColor: Color(0xff2244C7),
borderColor: Colors.transparent,
borderWidth: 3,
borderRadius: BorderRadius.all(Radius.circular(8),
),
children: [widget.value],
);
}).toList());
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