Flutter之Radio组件

/**
 * 单选框 点自己不能取消
 *const Radio({
    Key key,
    //groupValue 与 value 相等时 Radio 被选中
    @required this.value,//value 是当前Radio 的值
    @required this.groupValue,//groupValue 是组的值
    @required this.onChanged,
    this.activeColor,//选中时的颜色
    this.materialTapTargetSize,//点击区域尺寸，padded：向四周扩展48px区域;shrinkWrap：控件区域
    })
 */

/**
 * 系统封装的一个Radio
 *
    const RadioListTile({
    Key key,
    @required this.value,
    @required this.groupValue,
    @required this.onChanged,
    this.activeColor,//选中颜色
    this.title,
    this.subtitle,
    this.isThreeLine = false,//设置为true，高度变大
    this.dense,
    this.secondary,//左侧图标
    this.selected = false,
    this.controlAffinity = ListTileControlAffinity.platform,//leading：secondary在右侧；trailing：secondary在左侧；platform：根据平台确定
    })
 */

body: Column(
          children: <Widget>[
            Radio(
              value: "aaa",
              groupValue: groupValue,
              onChanged: (result) {
                setState(() {
                  groupValue = result;
                });
              },
              activeColor: Colors.red,
              materialTapTargetSize: MaterialTapTargetSize.padded,
            ),
            Radio(
              value: "bbb",
              groupValue: groupValue,
              onChanged: (result) {
                setState(() {
                  groupValue = result;
                });
              },
              activeColor: Colors.red,
              materialTapTargetSize: MaterialTapTargetSize.padded,
            ),

            RadioListTile(
              value: "ccc",
              groupValue: groupValue,
              onChanged: (result) {
                setState(() {
                  groupValue = result;
                });
              },
              activeColor: Colors.red,
              title: Text("标题"),
              subtitle: Text("副标题副标题副标题副标题副标题副标题副标题副标题副标题"),
                isThreeLine: false,
              secondary: Icon(Icons.alarm),
//                selected:true
            controlAffinity: ListTileControlAffinity.trailing,
            )
          ],
        ),