showModalBottomSheet(
                    context: context,
                    builder: (context) {
                      return ModalBottomSheet(this.selected, this.data, (selected, data) {
                        this.selected = selected;
                        this.data = data;
                      });
                    });
                    

import 'package:flutter/material.dart';

class ChoiceChipWidget extends StatefulWidget {
  final String label;
  final bool selected;

  final Function callback;

  ChoiceChipWidget(this.label, this.selected, {this.callback});

  @override
  State<StatefulWidget> createState() {
    return _ChoiceChipWidget();
  }
}

class _ChoiceChipWidget extends State<ChoiceChipWidget> {
  bool _value;

  @override
  void initState() {
    _value = widget.selected;
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return ChoiceChip(
      label: Text(widget.label),
      selected: _value,
      onSelected: (value) {
        setState(() {
          _value = value;
        });
        widget.callback(widget.label);
      },
    );
  }
}

import 'package:chip/choice_chip_widget.dart';
import 'package:flutter/material.dart';

class ModalBottomSheet extends StatefulWidget {

  final List<String> selected;

  final List data;

  final Function synchronous;

  ModalBottomSheet(this.selected, this.data, this.synchronous);

  _ModalBottomSheetState createState() => _ModalBottomSheetState();
}

enum ALertState { OK, CANCEL }

class _ModalBottomSheetState extends State<ModalBottomSheet>
    with SingleTickerProviderStateMixin {

  List<String> selected;

  List data;

  @override
  void initState() {
    selected = widget.selected;
    data = widget.data;
    super.initState();
  }

  @override
  void dispose() {
    widget.synchronous(selected, data);
    super.dispose();
  }
  
  void increase(String label) {
    selected.contains(label) ? selected.remove(label) : selected.add(label);
  }

  final GlobalKey<FormState> _formKey = GlobalKey<FormState>();

  Future<void> _askedToLead() async {
    switch (await showDialog<ALertState>(
        context: context,
        barrierDismissible: false,
        builder: (BuildContext context) {
          return AlertDialog(
            title: Form(
              key: _formKey,
              child: TextFormField(
                  decoration: InputDecoration(
                      hintText: '鱼饵名称',
                      hintStyle: TextStyle(
                        fontSize: 16.0,
                      )),
                  keyboardType: TextInputType.text,
                  validator: (String value) {
                    if (value.isEmpty) {
                      return '鱼饵名称不能为空';
                    }
                  },
                  onSaved: (String value) {
                    setState(() {
                      data.add(value);
                    });
                  }),
            ),
            actions: <Widget>[
              FlatButton(
                onPressed: () {
                  if (!_formKey.currentState.validate()) {
                    return;
                  }
                  Navigator.pop(context, ALertState.OK);
                },
                child: const Text('OK'),
              ),
              FlatButton(
                onPressed: () {
                  Navigator.pop(context, ALertState.CANCEL);
                },
                child: const Text('CANCEL'),
              ),
            ],
          );
        })) {
      case ALertState.OK:
        // Let's go.
        // ...
        print('OK');
        _formKey.currentState.save();
        break;
      case ALertState.CANCEL:
        // ...
        print('CANCEL');
        break;
    }
  }

  Widget build(BuildContext context) {
    List<Widget> wrap = data
        .map<Widget>((item) =>
            ChoiceChipWidget(item, selected.contains(item), callback: increase))
        .toList();
    wrap.add(IconButton(
      icon: Icon(Icons.add),
      onPressed: () => _askedToLead(),
    ));
    return Container(
      padding: EdgeInsets.only(top: 10.0, left: 4.0),
      child: Column(
        children: <Widget>[
          Center(
            child: Text(
              '选择鱼类型',
              style: TextStyle(fontSize: 18.0),
            ),
          ),
          SizedBox(
            height: 20.0,
          ),
          Wrap(
            spacing: 10.0,
            children: wrap,
          )
        ],
      ),
    );
  }
}