问如何使用flutter将复选框形状变为圆形

EN

bool _value = false;

@override
Widget build(BuildContext context) {
    return Scaffold(
        appBar: AppBar(
        title: Text("Circle CheckBox"),
        ),
        body: Center(
            child: InkWell(
        onTap: () {
            setState(() {
            _value = !_value;
            });
        },
        child: Container(
            decoration: BoxDecoration(shape: BoxShape.circle, color: Colors.blue),
            child: Padding(
            padding: const EdgeInsets.all(10.0),
            child: _value
                ? Icon(
                    Icons.check,
                    size: 30.0,
                    color: Colors.white,
                    )
                : Icon(
                    Icons.check_box_outline_blank,
                    size: 30.0,
                    color: Colors.blue,
                    ),
            ),
        ),
        )),
    );
}

Theme(
                data: ThemeData(
                    checkboxTheme: CheckboxThemeData(
                        shape: RoundedRectangleBorder(
                            borderRadius: BorderRadius.circular(25)))),
                child: CheckboxListTile(
                  value: model.specialSale,
                  secondary: Icon(
                    CustomIcons.percentage,
                    color: Theme.of(context).primaryColor,
                  ),
                  onChanged: (v) {
                
                  },
                  title: Text("Checked"),
                ),
              ),