颤振：如何在不进行API调用的情况下重新呈现视图？

所以我有一段代码，可以获取从一个地方到另一个地方的路线。 请看下面的图片

我需要为每个旅程添加隐藏的细节，除非单击“细节”按钮，否则我想在ExpansionFile/ExpansionPanel中显示数据-基本上是一个正在折叠的元素

问题是，当我使用按钮上的

setState（）{…}

时，它确实会显示数据，但也会再次调用API

方法

getData（）

在构建小部件中被触发，这就是为什么（我想）会发生这种情况，但我不知道如何解决这个问题

有更好的方法吗

对于任何帮助/改进，我们将不胜感激，因为我是新来的颤振=）

。。。
类(州){
字符串数据；
最终来自；
最终目的地；
最终类型；
最后一次；
静态变量date=new DateTime.now（）；
最终字符串formattedDate=新的日期格式（“yyyy-MM-dd”）。格式（日期）；
double _animatedHeight=100.0；
地图日志数据；
_计划旅程（this.from，this.to，this.type，this.time）；
Future getData（）异步{
http.Response-Response=等待http.get（url）；
data=response.body；
journeyData=json.decode（数据）；
debugPrint（journeyData.toString（））；
}
@凌驾
小部件构建（构建上下文）{
返回脚手架(
appBar:appBar(
标题：Text（'计划旅程'.toUpperCase（），
样式：TextStyle(
颜色：颜色，黑色，
尺寸：20，
fontWeight:fontWeight.bold
)
),
iconTheme:IconThemeData(
颜色：颜色（0xFF0984e3），
),
背景颜色：Colors.white，
),
resizeToAvoidBottomPadding:false，
正文：SingleChildScrollView(
子：约束框(
约束：BoxConstraints（），
孩子：未来建设者(
future:getData（），
生成器：（BuildContext上下文，异步快照）{
if（snapshot.connectionState==connectionState.done）{
列表元素=新列表（）；
对于（var i=0；i...
class _PlanJourney extends State<PlanJourney> {
  String data;
  final from;
  final to;
  final type;
  final time;
  static var date = new DateTime.now();
  final String formattedDate = new DateFormat('yyyy-MM-dd').format(date);

  double _animatedHeight = 100.0;

  Map<String,dynamic> journeyData;

  _PlanJourney(this.from, this.to, this.type, this.time);

  Future<String> getData() async {

    http.Response response = await http.get(url);
    data = response.body;
    journeyData = json.decode(data);
    debugPrint(journeyData.toString());
  }

  @override
  Widget build(BuildContext context){
    return Scaffold(
      appBar: AppBar(
        title: Text('Plan a journey'.toUpperCase(),
          style: TextStyle(
            color: Colors.black,
            fontSize: 20,
            fontWeight: FontWeight.bold
          )
        ),
        iconTheme: IconThemeData(
          color: Color(0xFF0984e3), 
        ),
        backgroundColor: Colors.white,
      ),
      resizeToAvoidBottomPadding: false,
      body: SingleChildScrollView(
        child: ConstrainedBox(
          constraints: BoxConstraints(),
          child: FutureBuilder(
            future: getData(),
            builder: (BuildContext context, AsyncSnapshot<String> snapshot) {
              if(snapshot.connectionState == ConnectionState.done){
                List<Widget> elements = new List<Widget>();
                for(var i = 0; i < journeyData['routes'].length; i++){
                  List<Widget> iconList = new List<Widget>();
                  String duration;
                  String start = journeyData['routes'][i]['departure_time'];
                  String end;
                  String stress = '2 min';
                  for(var j = 0; j < journeyData['routes'][i]['route_parts'].length; j++){
                    if(journeyData['routes'][i]['route_parts'][j]['mode'] == 'foot'){
                      iconList.add(IconTheme(
                          data: IconThemeData(
                            color: Color(0xFFbfcdd5)
                          ),
                          child: Icon(Icons.directions_walk),
                        )
                      );
                    } else if(journeyData['routes'][i]['route_parts'][j]['mode'] == 'tube'){
                        iconList.add(IconTheme(
                            data: IconThemeData(
                              color: Color(0xFFbfcdd5)
                            ),
                            child: Icon(Icons.train),
                          )
                        );
                    } else if(journeyData['routes'][i]['route_parts'][j]['mode'] == 'bus'){
                        iconList.add(IconTheme(
                            data: IconThemeData(
                              color: Color(0xFFbfcdd5)
                            ),
                            child: Icon(Icons.directions_bus),
                          )
                        );
                    }
                    duration = journeyData['routes'][i]['duration'];
                    end = journeyData['routes'][i]['arrival_time'];
                  }
                  elements.add(Container(
                    child: Column(
                      crossAxisAlignment: CrossAxisAlignment.stretch,
                      children: <Widget>[
                        Container(
                          alignment: Alignment.topLeft,
                          margin: EdgeInsets.only(left: 15, right: 15),
                          padding: EdgeInsets.all(10),
                          child: new Wrap(
                            direction: Axis.horizontal,
                            crossAxisAlignment: WrapCrossAlignment.start,
                            spacing: 5,
                            runSpacing: 5,
                            children: iconList
                          ),
                        ),
                        Container(
                          alignment: Alignment.topLeft,
                          margin: EdgeInsets.only(left: 15, right: 15),
                          padding: EdgeInsets.all(10),
                          child: new Row(
                            mainAxisAlignment: MainAxisAlignment.spaceBetween,
                            children: <Widget> [
                              Column(
                                children: <Widget>[
                                  Text('Duration',
                                    style: TextStyle(
                                      fontFamily: "Gotham Pro",
                                      fontWeight: FontWeight.w300,
                                      fontSize: 14
                                    )
                                  ),
                                  Padding(
                                    padding: EdgeInsets.only(top: 5),
                                  ),
                                  Text(duration)
                                ],
                              ),
                              Column(
                                children: <Widget>[
                                  Text('Start',
                                    style: TextStyle(
                                      fontFamily: "Gotham Pro",
                                      fontWeight: FontWeight.w300,
                                      fontSize: 14
                                    )
                                  ),
                                  Padding(
                                    padding: EdgeInsets.only(top: 5),
                                  ),
                                  Text(start),
                                ],
                              ),
                              Column(
                                children: <Widget>[
                                  Text('End',
                                    style: TextStyle(
                                      fontFamily: "Gotham Pro",
                                      fontWeight: FontWeight.w300,
                                      fontSize: 14
                                    )
                                  ),
                                  Padding(
                                    padding: EdgeInsets.only(top: 5),
                                  ),
                                  Text(end),
                                ],
                              ),
                              Column(
                                children: <Widget>[
                                  Text('Stress',
                                    style: TextStyle(
                                      fontFamily: "Gotham Pro",
                                      fontWeight: FontWeight.w300,
                                      fontSize: 14
                                    )
                                  ),
                                  Padding(
                                    padding: EdgeInsets.only(top: 5),
                                  ),
                                  Text(stress)
                                ],
                              )
                            ]
                          ),
                        ),
                        Container(
                          alignment: Alignment.topLeft,
                          margin: EdgeInsets.only(left: 15, right: 15),
                          child: Row(
                            children: <Widget>[
                              OutlineButton(

                                child: Text('Details', 
                                  style: TextStyle(
                                    color: Color(0xFF0c85e4), 
                                    fontFamily: "Gotham Pro",
                                    fontWeight: FontWeight.w700
                                  )
                                ),
                                borderSide: BorderSide(
                                  color: Color(0xFF0c85e4), //Color of the border
                                  style: BorderStyle.solid, //Style of the border
                                  width: 2, //width of the border
                                ),
                                shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(20)),
                                onPressed: ()=>setState((){
                                    _animatedHeight!=0.0  _animatedHeight=0.0:_animatedHeight=100.0;
                                  }
                                ),
                              ),
                              Padding(
                                padding: EdgeInsets.only(left: 15, top: 15),
                              ),
                              RaisedButton(
                                child: Text('Save', 
                                  style: TextStyle(
                                    color: Colors.white,
                                    fontFamily: "Gotham Pro",
                                    fontWeight: FontWeight.w700,
                                  )
                                ),
                                color: Color(0xFF08b894),
                                shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(20)),
                                onPressed: (){},
                              )
                            ],
                          )
                        ),
                        AnimatedContainer(duration: const Duration(milliseconds: 120),
                          child: new Text("Journey data will go here"),
                          height: _animatedHeight,
                          color: Colors.tealAccent,
                          width: 200.0,
                        ),
                        Divider()
                      ],
                    ),
                  ));
                }
                return new Column(children: elements);
              }else if(snapshot.connectionState == ConnectionState.waiting){
                return Text("loading ...");
              }
            },
          ),
        )
      )
    );
  }

}

...
future: getData()
...

...
var dataFetched;

@override
  void initState(){
    super.initState();
    dataFetched = getData();
  }

...
FutureBuilder(
  future: dataFetched,
     builder: (BuildContext context, AsyncSnapshot<String> snapshot) {
        if(snapshot.connectionState == ConnectionState.done){...}
     }
  }
)               
...