Wrap

类似于ListView，用于显示多个信息时使用

每一个子控件顺延前一个控件。

Wrap(
  spacing: 8.0, // gap between adjacent chips
  runSpacing: 4.0, // gap between lines
  children: <Widget>[
    Chip(
      avatar: CircleAvatar(backgroundColor: Colors.blue.shade900, child: Text('AH')),
      label: Text('Hamilton'),
    ),
    Chip(
      avatar: CircleAvatar(backgroundColor: Colors.blue.shade900, child: Text('ML')),
      label: Text('Lafayette'),
    ),
    Chip(
      avatar: CircleAvatar(backgroundColor: Colors.blue.shade900, child: Text('HM')),
      label: Text('Mulligan'),
    ),
    Chip(
      avatar: CircleAvatar(backgroundColor: Colors.blue.shade900, child: Text('JL')),
      label: Text('Laurens'),
    ),
  ],
)