Question

Checkbox(
                  onChanged: (bool value) {
                    setState(() {
                      isHighBloodDisease = value;
                    });
                  },
                  value: isHighBloodDisease,
                ),

这是我的代码，当我单击复选框时，检查不是 appper 但是当我关闭 dropDownList 并重新打开它时，我选择的框被选中，我尝试打印该值，当我单击它时它可以工作打印 true

return SizedBox(
      height: 50,
      width: 350,
      child: DropdownButtonFormField(
        iconSize: 50,
        iconEnabledColor: white,
        decoration: InputDecoration(
          hintText: 'الامراض المزمنة',
          hintStyle: TextStyle(
              fontSize: 23, fontWeight: FontWeight.bold, color: white),
          enabledBorder: OutlineInputBorder(
            borderSide: BorderSide(
              color: white,
            ),
            borderRadius: BorderRadius.circular(30.0),
          ),
        ),
        items: [
          DropdownMenuItem(
            child: Row(
              mainAxisAlignment: MainAxisAlignment.end,
              children: <Widget>[
                Text(
                  chronicDisease[0]['disease'],
                  style: textStyle,
                ),
                Checkbox(
                  value: isHeartDisease,
                  onChanged: (bool value) {
                    setState(() {
                      isHeartDisease = value;
                    });
                  },
                ),
              ],
            ),
          ),
DropdownMenuItem(
            child: Row(
              mainAxisAlignment: MainAxisAlignment.end,
              children: <Widget>[
                Text(
                  chronicDisease[4]['disease'],
                  style: textStyle,
                ),
                Checkbox(
                  onChanged: (bool value) {
                    setState(() {
                      isHighBloodDisease = value;
                    });
                  },
                  value: isHighBloodDisease,
                ),
              ],
            ),
          )
        ].toList(),
        onChanged: (value) {},
      ),
    );
  }
}

Answer 1

试试下面的代码片段：

<块引用>

为复选框创建一个 statefullwidget：

class CheckboxSelectorPage extends StatefulWidget {
  bool isChecked = false;

  CheckboxSelectorPage(this.isChecked, {Key key}) : super(key: key);

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

class _CheckboxSelectorPageState extends State<CheckboxSelectorPage> {
  @override
  Widget build(BuildContext context) {
    return Checkbox(
      onChanged: (bool value) {
        widget.isChecked = value;
        print("value: $value Is mounted: $mounted");
        setState(() {
          widget.isChecked = value;
        });
      },
      value: widget.isChecked,
    );
  }
}

<块引用>

将 Checkbox 小部件替换为：

 CheckboxSelectorPage(),

此示例已在 dartpad.dev

中测试

Answer 2

回复您的评论：

<块引用>

我有另一个问题，我正在开发一个阿拉伯语应用程序，所以我想要下侧的下拉箭头，我该如何更改对齐方式？

用 DropdownButtonFormField 小部件包裹 Directionality：

SizedBox(
    height: 50,
    width: 350,
        child: Directionality(
        textDirection: TextDirection.rtl,
            child: DropdownButtonFormField(
                 iconSize: 50,
                 decoration: InputDecoration(
                    hintText: 'الامراض المزمنة',

有关更多信息，请查看此问题： right-to-left (RTL) in flutter

颤振中的复选框不会改变

2 个答案: