[英]Can I use same flutter app for both android and ios apps?
[英]How can I use both required and simple argument in same constructor in flutter 3?
class ReusableCard extends StatelessWidget {
ReusableCard({required this.colour, this.cardChild});
final Color colour;
Widget cardChild;
@override
Widget build(BuildContext context) {
return Container(
child: cardChild,
margin: EdgeInsets.all(15.0),
decoration: BoxDecoration(
color: Color(0xFF1D1E33),
borderRadius: BorderRadius.circular(10.0),
),
);
}
}
如果您不希望它需要它,您需要通过添加一个?
到变量的类型。 所以改变
Widget cardChild;
至
Widget? cardChild;
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.