flutter - 在 Flutter 中循环遍历列表数据

问题描述

在 Flutter 中循环嵌套列表的最佳方法是什么？我正在使用以下代码，但我认为这不是最佳做法，因为我在同一个父小部件内循环遍历列表两次：

class DetailItem extends StatelessWidget {

  DetailItem({
    required this.index,
    required this.data,
    required this.lastItem,
  });

  final List data;
  final int index;
  final bool lastItem;
  String? paragraph;
  int id = 0;

  @override
  Widget build(BuildContext context) {
    final row = SafeArea(
      top: false,
      bottom: false,
      minimum: const EdgeInsets.only(
        left: 10,
        top: 0,
        bottom: 8,
        right: 8,
      ),
      child: Row(
        children: <Widget>[
          Expanded(
            child: Padding(
                padding: const EdgeInsets.only(
                  left: 10,
                  top: 8,
                  bottom: 8,
                  right: 8,
                ),
                child: Column(
                  children: <Widget>[
                    for (var s in data) //loop
                      Column(
                        children: <Widget>[
                          SizedBox(height: 30),
                          Align(
                            alignment: Alignment.centerLeft,
                            child: Text(s.name.toUpperCase(), style: Styles.itemRowItemLanguage,  textAlign: TextAlign.start),
                          ),
                          SizedBox(height: 5),
                          Align(
                            alignment: Alignment.centerLeft,
                            child: Text(s.paragraph, style: Styles.itemRowItemName),
                          ),
                        ],
                      )
                  ],
                  ),
                ),
              ),
          Column (
            children: <Widget>[
              new CupertinoButton(
                padding: EdgeInsets.zero,
                minSize: 0,
                child: Icon(CupertinoIcons.share, semanticLabel: 'Share'),
                onPressed: () {
                  Share.share(this.paragraph!);
                },
              ),
              new CupertinoButton(
                padding: EdgeInsets.zero,
                child: Icon(CupertinoIcons.bookmark, semanticLabel: 'Bookmark'),
                onPressed: () {
                  final model = Provider.of<BookmarkModel>(context, listen: false);
                  for (var s in data) // looping here again
                  model.toggleBookmarkStatus(s.id);
                },
              ),
            ],
          ),
        ],
      ),
    );

    if (lastItem) {
      return row;
    }

    return Column(
      children: <Widget>[
        row,
        Padding(
          padding: const EdgeInsets.only(
            left: 0,
            right: 0,
          ),
          child: Container(
            height: 1,
            color: Styles.itemRowDivider,
          ),
        ),
      ],
    );
  }

}

当我在嵌套列小部件外但在父小部件内运行循环时，它显示小部件中的undefined name 's'错误CupertinoButton：

final row = SafeArea(
      top: false,
      bottom: false,
      minimum: const EdgeInsets.only(
        left: 10,
        top: 0,
        bottom: 8,
        right: 8,
      ),
      child: Row(
        children: <Widget>[
         for (var s in data) //running the loop inside parent widget but outside the child widget

标签： flutterdart

flutter - 在 Flutter 中循环遍历列表数据

问题描述

解决方案

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