如何声明selectedGender变量?我有一个初始化错误。该变量位于StatefullWidget内部。
enum Gendertype {male, female}
class _MyHomePageState extends State<MyHomePage> {
Gendertype selectedGender;
@override
Widget build(BuildContext context) {
return Column(
child: Expanded(
child: GestureDetector(
onTap: (){
setState(() {
selectedGender= Gendertype.male;
});
},
child: ReusedCard(
labledcolor: selectedGender==Gendertype.male?
inactivekcardcolor:activekcardcolor,
childCard: CardIcon(genderIcon: FontAwesomeIcons.mars,
labletype: "Male",
),
),
)
),
);
}
根据空安全规则,您可以选择以下选项:
- 将
selectedGender
声明为可为null的变量:
Gendertype? selectedGender;
- 定义变量的第一个值:
Gendertype selectedGender = Gendertype.male