flutter 自定义小部件未显示 children

Question

我正在按照构建自定义小部件的过时教程进行操作，但到目前为止我无法使其在自定义小部件中可见：RusableCard children 中放置的任何内容在应用程序中均不可见。我能做什么？

....

                  child: ReusableCard(
                    color: activeCardColor,
                    cardChild: Column(
                      mainAxisAlignment: MainAxisAlignment.center,
                      children: [
                        FaIcon(FontAwesomeIcons.search, size: 80),                       
                        SizedBox(height: 15),
                        Text(
                          'MALE',
                          style: TextStyle(
                            fontSize: 80.0,
                            color: Color(0xFF8D8E96),
                      
                ...

class ReusableCard extends StatelessWidget {
  ReusableCard({
    required this.color,
    this.cardChild,
  });

  final Color color;
  final Widget? cardChild;

  @override
  Widget build(BuildContext context) {
    return Container(
      margin: EdgeInsets.all(15),
      decoration: BoxDecoration(
        color: color,
        borderRadius: BorderRadius.circular(10),
      ),
    );
  }
}

Answer 1

您在 ReusableCard 上缺少 Container child。在容器上调用 child。确保处理空值。

class ReusableCard extends StatelessWidget {
  ReusableCard({
    required this.color,
    this.cardChild,
  });

  final Color color;
  final Widget? cardChild;

  @override
  Widget build(BuildContext context) {
    return Container(
      margin: EdgeInsets.all(15),
      decoration: BoxDecoration(
        color: color,
        borderRadius: BorderRadius.circular(10),
      ),
     child:cardChild!=null? cardChild: null,// handle here 
    );
  }
}

flutter 自定义小部件未显示 children

flutter custom widget is not showing children

widget

flutter