flutter中ExpansionPanelList收缩面板

ExpansionPanelList参数

const ExpansionPanelList({
  Key key,
  this.children = const <ExpansionPanel>[],//子部件
  this.expansionCallback,
  this.animationDuration = kThemeAnimationDuration,
})

ExpansionPanel参数

ExpansionPanel({
  @required this.headerBuilder, //头部
  @required this.body,//主题
  this.isExpanded = false,
  this.canTapOnHeader = false,
})

//定义一个收缩面板的类型；
class IsExpandedItem{
  final String headerTitle;//标题
  Widget body;//收缩面板描述
  bool isExpanded;//是否收缩
  int index;//下标用来排它
  IsExpandedItem({this.headerTitle,this.body,this.isExpanded,this.index});
}

//定义收缩面板的子部件
List<IsExpandedItem> _isExpandedItems;

void initState() {
  // TODO: implement initState
  //初始化收缩面板的子部件
  _isExpandedItems=List<IsExpandedItem>.generate(10, (int index){
    return IsExpandedItem(
      index: index,
      headerTitle: '第$index个面板',
      body:Container(
        padding: EdgeInsets.all(16.0),
        width: double.infinity,
        child: Text('第$index个收缩面板'),
      ),
      isExpanded: false,
    );
  });

  super.initState();
}

ExpansionPanelList(
  expansionCallback: (int index,bool isExpanded){
    //实现收缩面板排它
    _isExpandedItems.forEach((item){
      if(item.index==index){
        //取反，经典取反方法
        print(index);
        setState(() {
          item.isExpanded=!isExpanded;
        });
      }else{
        setState(() {
          item.isExpanded=false;
        });
      }
    });
  },
  children:  _isExpandedItems.map((IsExpandedItem item){
        return ExpansionPanel(
          isExpanded: item.isExpanded,
          body: item.body,
          headerBuilder: (BuildContext context,bool isExpanded){
            return item.body;
          }
        );
    }).toList(),

),