Flutter笔记18：CheckBox复选框

class DemoPage extends StatefulWidget {
  DemoPage({Key key}) : super(key: key);

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

class _DemoPageState extends State<DemoPage> {
  var currentIndex = 0;

  @override
  Widget build(BuildContext context) {
    return Column(
      children: [
        Checkbox(
            //激活时的颜色
            activeColor: Colors.red,
            //是否被选中
            value: 0 == currentIndex,
            //复选框是否有空值，如果为true，则有true、false和空三个值，false则只有true和false两个值
            tristate: false,
            onChanged: (bool check) {
              setState(() {
                if (check) {
                  currentIndex = 0;
                }
              });
            }),
        Checkbox(
            //激活时的颜色
            activeColor: Colors.red,
            //是否被选中
            value: 1 == currentIndex,
            onChanged: (bool check) {
              setState(() {
                if (check) {
                  currentIndex = 1;
                }
              });
            }),
      ],
    );
  }
}