ExpansionPanel可伸缩列表的使用

直接看代码。

import 'package:flutter/material.dart';

// stores ExpansionPanel state information
class Item {
  Item({
    this.expandedValue,
    this.headerValue,
    this.isExpanded = false,
  });

  String expandedValue;
  String headerValue;
  bool isExpanded;
}

List<Item> generateItems(int numberOfItems) {
  return List.generate(numberOfItems, (int index) {
    return Item(
      headerValue: 'Panel $index',
      expandedValue: 'This is item number $index',
    );
  });
}

class MyStatefulWidget extends StatefulWidget {
  MyStatefulWidget({Key key}) : super(key: key);

  @override
  _MyStatefulWidgetState createState() => _MyStatefulWidgetState();
}

class _MyStatefulWidgetState extends State<MyStatefulWidget> {
  List<Item> _data = generateItems(8);

  @override
  Widget build(BuildContext context) {
    return SingleChildScrollView(
      child: Container(
        child: _buildPanel(),
      ),
    );
  }

  Widget _buildPanel() {
    return ExpansionPanelList(
      expansionCallback: (int index, bool isExpanded) {
        setState(() {
          _data[index].isExpanded = !isExpanded;
        });
      },
      children: _data.map<ExpansionPanel>((Item item) {
        return ExpansionPanel(
          headerBuilder: (BuildContext context, bool isExpanded) {
            return ListTile(
              title: Text(item.headerValue),
            );
          },
          body: ListTile(
              title: Text(item.expandedValue),
              subtitle: Text('To delete this panel, tap the trash can icon'),
              trailing: Icon(Icons.delete),
              onTap: () {
                setState(() {
                  _data.removeWhere((currentItem) => item == currentItem);
                });
              }),
          isExpanded: item.isExpanded,
        );
      }).toList(),
    );
  }
}

the demo for how to using is as the follow, create a simple page for it, then use it as you want.

class ExpansionDemoPage extends StatefulWidget {
@override
_ExpansionDemoPageState createState() => _ExpansionDemoPageState();
}

class _ExpansionDemoPageState extends State<ExpansionDemoPage> {
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text("Search Page"),
),
body: MyStatefulWidget(),
);
}
}

then you will see how it display. 这是可伸缩列表的简单使用， 你可以自定义自己想要的控件。