Flutter Flatter Future build装载时不显示容器_Flutter_Dart

Flutter Flatter Future build装载时不显示容器

flutter dart

Flutter Flatter Future build装载时不显示容器,flutter,dart,Flutter,Dart,我正在尝试在我的应用程序中使用futurebuild，但在加载功能后，它仍然显示加载指示器，而不显示容器这是我的密码 class _MyHomePageState extends State<MyHomePage> { bool showApp = false; var _questions = new List<Questions>(); _getQuestions() { API.getUsers().then((response) {

我正在尝试在我的应用程序中使用futurebuild，但在加载功能后，它仍然显示加载指示器，而不显示容器

这是我的密码

class _MyHomePageState extends State<MyHomePage> {
  bool showApp = false;
   var _questions = new List<Questions>();
  _getQuestions() {
    API.getUsers().then((response) {
      setState(() {

        Iterable list = json.decode(response.body);
        print(list);
        print(list);
        _questions = list.map((model) => Questions.fromJson(model)).toList();
        print(_questions);
        showApp = true;
      });
    });
  }

  int index = 0;
  bool shouldShow = false;

  @override
  Widget build(BuildContext context) {

    int size = _questions?.length;

    void nextQuestion() {
      if (index < size - 1)
        setState(() {
          index++;
        });
      print(index);
    }

    double percentage1Calculate() {
      int wouldClick = 12;
      int ratherClick = 13;
      double percentage1 = wouldClick / (wouldClick + ratherClick) * 100;
      return percentage1;
    }

    double percentage2Calculate() {
      int wouldClick = 2;
      int ratherClick = 3;
      double percentage2 = ratherClick / (wouldClick + ratherClick) * 100;
      return percentage2;
    }

    void percengtageTrigger(){
      setState(() {
        shouldShow = true;
      });
      Timer timer = Timer(Duration(milliseconds: 1350), () {
        setState(() {
          shouldShow = false;
        });
      });
    }

    final PrimaryColor = const Color(0xff404040);

    final PreferredSizeWidget appBar = AppBar(
      centerTitle: true,
      title: Text(
        'Would you Rather',
        style: TextStyle(fontFamily: 'FredokaOne'),
      ),
      backgroundColor: PrimaryColor,
    );
    double stackHeight = (MediaQuery.of(context).size.height -
        appBar.preferredSize.height -
        MediaQuery.of(context).padding.top);
    double stackWidth = MediaQuery.of(context).size.width;
    return FutureBuilder(


        initialData:null, //initial default data if you have some
        future: _getQuestions(),
        builder:(BuildContext context, AsyncSnapshot<String> snapshot){
           if(snapshot.hasData){
             print("Data found, You can continue");
             return Center(
               child: Container(
                 child: Text('data avail'),

               ),
             );
           }
           else if (snapshot.hasError) {
             return Center(
               child: Container(
                 child: Text('error'),

               ),
             );
           }
           else{
             print("loading");
             return CircularProgressIndicator();
           }
        }
    );
  }
}

使用以下命令：

class _MyHomePageState extends State<MyHomePage> {
  bool showApp = false;
  Future myQuestionsFuture;

  var _questions = new List<Questions>();

  @override
  void initState() {
    myQuestionsFuture = _getQuestions();
    super.initState();
  }

  Future<List<Questions>> _getQuestions() async {
    final response = await API.getUsers();
    Iterable list = json.decode(response.body);
    print(list);
    print(list);
    _questions = list.map((model) => Questions.fromJson(model)).toList();
    print(_questions);
    setState(() {
      showApp = true;
    });
    return _questions;
  }

  int index = 0;
  bool shouldShow = false;

  @override
  Widget build(BuildContext context) {
    int size = _questions?.length;

    void nextQuestion() {
      if (index < size - 1)
        setState(() {
          index++;
        });
      print(index);
    }

    double percentage1Calculate() {
      int wouldClick = 12;
      int ratherClick = 13;
      double percentage1 = wouldClick / (wouldClick + ratherClick) * 100;
      return percentage1;
    }

    double percentage2Calculate() {
      int wouldClick = 2;
      int ratherClick = 3;
      double percentage2 = ratherClick / (wouldClick + ratherClick) * 100;
      return percentage2;
    }

    void percengtageTrigger() {
      setState(() {
        shouldShow = true;
      });
      Timer timer = Timer(Duration(milliseconds: 1350), () {
        setState(() {
          shouldShow = false;
        });
      });
    }

    final PrimaryColor = const Color(0xff404040);

    final PreferredSizeWidget appBar = AppBar(
      centerTitle: true,
      title: Text(
        'Would you Rather',
        style: TextStyle(fontFamily: 'FredokaOne'),
      ),
      backgroundColor: PrimaryColor,
    );
    double stackHeight = (MediaQuery.of(context).size.height -
        appBar.preferredSize.height -
        MediaQuery.of(context).padding.top);
    double stackWidth = MediaQuery.of(context).size.width;
    return FutureBuilder<List<Questions>>(
        initialData: null, //initial default data if you have some
        future:myQuestionsFuture,
        builder: (BuildContext context, AsyncSnapshot<List<Questions>> snapshot) {
          if (snapshot.connectionState == ConnectionState.done) {
            if (snapshot.hasData) {
              print("Data found, You can continue");
              return Center(
                child: Container(
                  child: Text('data avail'),
                ),
              );
            } else if (snapshot.hasError) {
              return Center(
                child: Container(
                  child: Text('error'),
                ),
              );
            }
          } else {
            print("loading");
            return CircularProgressIndicator();
          }
        });
  }
}

class\u MyHomePageState扩展状态{
bool showApp=false；
未来我的问题未来；
var_questions=新列表（）；
@凌驾
void initState（）{
MyQuestions未来=_getQuestions（）；
super.initState（）；
}
Future\u getQuestions（）异步{
最终响应=等待API.getUsers（）；
Iterable list=json.decode（response.body）；
打印（列表）；
打印（列表）；
_questions=list.map（（model）=>questions.fromJson（model））.toList（）；
打印问题；
设置状态（）{
showApp=true；
});
返回问题；
}
int指数=0；
bool shouldShow=false；
@凌驾
小部件构建（构建上下文）{
整数大小=_个问题？.length；
void nextQuestion（）{
如果（索引<大小-1）
设置状态（）{
索引++；
});
打印（索引）；
}
双百分比1计算（）{
int-wouldClick=12；
int-ratherClick=13；
双百分比1=wouldClick/（wouldClick+ratherClick）*100；
返回百分比1；
}
双百分比2计算（）{
int-wouldClick=2；
int-ratherClick=3；
百分之二=ratherClick/（wouldClick+ratherClick）*100；
返回百分比2；
}
void percengtageTrigger（）{
设置状态（）{
shouldShow=true；
});
计时器=计时器（持续时间（毫秒：1350），（）{
设置状态（）{
shouldShow=false；
});
});
}
最终原色=常量颜色（0xff404040）；
最终PreferredSizeWidget appBar=appBar(
标题：对，
标题：正文(
“你愿意吗？”，
样式：TextStyle（fontFamily:'FredokaOne'），
),
背景色：原色，
);
double stackHeight=（MediaQuery.of（context）.size.height-
appBar.preferredSize.height-
MediaQuery.of（context.padding.top）；
double stackWidth=MediaQuery.of（context）.size.width；
回归未来建设者(
initialData:null，//如果有初始默认数据
未来：我的问题未来，
生成器：（BuildContext上下文，异步快照）{
if（snapshot.connectionState==connectionState.done）{
if（snapshot.hasData）{
打印（“找到数据，可以继续”）；
返回中心(
子：容器(
子项：文本（“数据可用”），
),
);
}else if（snapshot.hasrerror）{
返回中心(
子：容器(
子项：文本（'error'），
),
);
}
}否则{
打印（“加载”）；
返回循环ProgressIndicator（）；
}
});
}
}

Its显示此错误类型“Future”不是“Future”类型的子类型

class _MyHomePageState extends State<MyHomePage> {
  bool showApp = false;
  Future myQuestionsFuture;

  var _questions = new List<Questions>();

  @override
  void initState() {
    myQuestionsFuture = _getQuestions();
    super.initState();
  }

  Future<List<Questions>> _getQuestions() async {
    final response = await API.getUsers();
    Iterable list = json.decode(response.body);
    print(list);
    print(list);
    _questions = list.map((model) => Questions.fromJson(model)).toList();
    print(_questions);
    setState(() {
      showApp = true;
    });
    return _questions;
  }

  int index = 0;
  bool shouldShow = false;

  @override
  Widget build(BuildContext context) {
    int size = _questions?.length;

    void nextQuestion() {
      if (index < size - 1)
        setState(() {
          index++;
        });
      print(index);
    }

    double percentage1Calculate() {
      int wouldClick = 12;
      int ratherClick = 13;
      double percentage1 = wouldClick / (wouldClick + ratherClick) * 100;
      return percentage1;
    }

    double percentage2Calculate() {
      int wouldClick = 2;
      int ratherClick = 3;
      double percentage2 = ratherClick / (wouldClick + ratherClick) * 100;
      return percentage2;
    }

    void percengtageTrigger() {
      setState(() {
        shouldShow = true;
      });
      Timer timer = Timer(Duration(milliseconds: 1350), () {
        setState(() {
          shouldShow = false;
        });
      });
    }

    final PrimaryColor = const Color(0xff404040);

    final PreferredSizeWidget appBar = AppBar(
      centerTitle: true,
      title: Text(
        'Would you Rather',
        style: TextStyle(fontFamily: 'FredokaOne'),
      ),
      backgroundColor: PrimaryColor,
    );
    double stackHeight = (MediaQuery.of(context).size.height -
        appBar.preferredSize.height -
        MediaQuery.of(context).padding.top);
    double stackWidth = MediaQuery.of(context).size.width;
    return FutureBuilder<List<Questions>>(
        initialData: null, //initial default data if you have some
        future:myQuestionsFuture,
        builder: (BuildContext context, AsyncSnapshot<List<Questions>> snapshot) {
          if (snapshot.connectionState == ConnectionState.done) {
            if (snapshot.hasData) {
              print("Data found, You can continue");
              return Center(
                child: Container(
                  child: Text('data avail'),
                ),
              );
            } else if (snapshot.hasError) {
              return Center(
                child: Container(
                  child: Text('error'),
                ),
              );
            }
          } else {
            print("loading");
            return CircularProgressIndicator();
          }
        });
  }
}