FilterChip 过滤小条

和Chip组件类似的样式，具有选中与否的属性和选中事件。当选中时左侧组件上层会被✔️遮罩。

相关组件

Chip ChoiceChip ActionChip InputChip RawChip

FilterChip可接受选择事件

【selected】: 是否选择 【bool】
【onSelected】: 选择事件 【Function(bool)】
【selectedColor】: 选择后的颜色 【Color】
【selectedShadowColor】: 选择后的阴影颜色 【Color】,

import 'package:flutter/material.dart';
class CustomFilterChip extends StatefulWidget {
  @override
  _CustomFilterChipState createState() => _CustomFilterChipState();
}
class _CustomFilterChipState extends State<CustomFilterChip> {
  final Map<String, String> map = {
    'A': 'Ant',
    'B': 'Bug',
    'C': 'Cat',
    'D': 'Dog',
  };
  List<String> _selected = <String>[];
  @override
  Widget build(BuildContext context) {
    return Column(
      mainAxisAlignment: MainAxisAlignment.center,
      children: <Widget>[
        Wrap(
          children: map.keys.map((key) =>
              _buildChild(key)).toList(),
        ),
        Container(
            padding: EdgeInsets.all(10),
            child: Text('您已选择: ${_selected.join(', ')}')),
      ],
    );
  }
  Padding _buildChild(String key) {
    return Padding(
      padding: const EdgeInsets.all(4.0),
      child: FilterChip(
        selectedColor: Colors.orange.withAlpha(55),
        selectedShadowColor: Colors.blue,
        shadowColor: Colors.orangeAccent,
        pressElevation: 5,
        elevation: 3,
        avatar: CircleAvatar(child: Text(key)),
        label: Text(map[key]),
        selected: _selected.contains(map[key]),
        onSelected: (bool value) {
          setState(() {
            if (value) {
              _selected.add(map[key]);
            } else {
              _selected.removeWhere((name) => name == map[key]);
            }
          });
        },
      ),
    );
  }
}