我可以为FutureBuilder使用多个方法吗?

63
     @override
      Widget build(BuildContext context) {
        widget.groupid;
        widget.event_id;
        var futureBuilder = new FutureBuilder(
          future: _getAllTickets(),

          builder: (BuildContext context, AsyncSnapshot snapshot) {
            print(snapshot.connectionState);
            switch (snapshot.connectionState) {
              case ConnectionState.none:
              case ConnectionState.waiting:
                return new Text('...');
              default:
                if (snapshot.hasError)
                  return new Text('Error: ${snapshot.error}');
                else
                  return createListTickets(context, snapshot);
            }
          },
        );



    return new Scaffold(

      body: futureBuilder,

    );
  }

  Widget createListTickets(BuildContext context, AsyncSnapshot snapshot) {
    List values = snapshot.data;

     child: new Card(

                child:
                new Column(mainAxisSize: MainAxisSize.min, children: <Widget>[
                  new Text(
                      values[index]["ticket_type_id"].toString(), style:
                  const TextStyle(
                      fontFamily: 'Poppins',
                      fontWeight: FontWeight.w600,
                      fontSize: 25.0)),
}


  _getAllTickets() async {
    final response = await http.get(
        "https...}"
        , headers: {
      HttpHeaders.AUTHORIZATION: access_token
    });

    returnTickets = json.decode(response.body);
    return returnTickets;
  }


  _getTicketType() async {
    for (i = 0; i < (returnTickets?.length ?? 0); i++) {
      /*print("https....);*/
     final responseType = await http.get(
          "https...}"
          , headers: {
        HttpHeaders.AUTHORIZATION: access_token
      });

      Map<String, dynamic> hey = json.decode(responseType.body);


    }

大家好,我有一个问题。由于我正在发送多个API请求并根据返回的响应动态构建一个卡片,我想知道是否可以在future中包含不止一个方法:_getAllTickets() +(另一个方法),因为我想用方法_getTicketType()获得的新索引响应“名称”替换values[index] [“ticket_type_id”]中的值。 提前感谢!

1个回答

192
您可以使用Future.wait(Future[])来返回Future列表。
Future<String> foo;
Future<int> bar;
FutureBuilder(
  future: Future.wait([bar, foo]),
  builder: (context, AsyncSnapshot<List<dynamic>> snapshot) {
    snapshot.data[0]; //bar
    snapshot.data[1]; //foo
  },
);

1
感谢您的回复,我按照您的建议尝试后仍然遇到了错误: 没有找到方法'then'在空值上被调用。接收器:null。 尝试调用:then <dynamic>(Closure:(T) => Null, onError; Closure:(dynamic,dynamic) => Null) - heyr
非常好,感谢您的回答。 - wanz

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