切换按钮在Flutter中不切换

如何解决切换按钮在Flutter中不切换

我已经创建了一个带有ToggleButtons的GridList，但是当我尝试在彼此之间切换按钮时什么也没发生。有任何想法吗？我有一个列表isSelected，我在setState中将其称为。布局很好，但是一旦我使用GridView，它似乎就会更改setState。

class Backgrounds extends StatefulWidget {

  @override
  _BackgroundsState createState() => _BackgroundsState();
}

class _BackgroundsState extends State<Backgrounds> {

  List<bool> isSelected;

  void initState() {
    isSelected = [true,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/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());
}
}

解决方法

问题出在切换按钮的“ onPressed（）”函数上。由于“网格列表”视图是由地图生成的，因此每次“切换按钮”子级的子级列表大小为1时，“ OnPressed（）”中的index参数将始终为0。我建议使用“ widget.key”在地图中，因为这样可以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/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());