Question

我真的被这部分代码所困扰（我是Flutter的初学者）。我想显示秒表计时器和距geolocator的总距离，但是秒表只是在“ geolocation”移动时更新。

按下按钮时，我将其称为：

void _toggleListening() {
     if (_positionStreamSubscription == null) {
      const LocationOptions locationOptions =
          LocationOptions(accuracy: LocationAccuracy.best);
      final Stream<Position> positionStream =
          Geolocator().getPositionStream(locationOptions);

      _positionStreamSubscription = positionStream.listen((Position position) {
        setState(() {
          _positions.add(position);
          _allPositions = _positions;
          _positionRealTime = position;
          updatePinOnMap();
          print('all lenght ${_allPositions.length}');
          totalDistanceAux = 0.0;
          for (var i = 0; i < _allPositions.length - 1; i++) {
            totalDistanceAux = totalDistanceAux +
                distance.as(
                  LengthUnit.Meter,
                  LatLng(_allPositions[i].latitude, _allPositions[i].longitude),
                  LatLng(_allPositions[i + 1].latitude,
                      _allPositions[i + 1].longitude),
                );
          }
          totalDistance = totalDistanceAux;
          print('total distance $totalDistance');
        });
      });
      _positionStreamSubscription.pause();
      _stopwatch.stop();
    } else {
      setState(() {
        if (_positionStreamSubscription.isPaused == true) {
          _positionStreamSubscription.resume();
          _stopwatch.start();
        }
      });
    }
  }

我正在与FutureBuilder一起显示：

FutureBuilder<GeolocationStatus>(
                        future: Geolocator().checkGeolocationPermissionStatus(),
                        builder: (BuildContext context,
                            AsyncSnapshot<GeolocationStatus> snapshot) {

距离和计时器工作正常，唯一的问题是计时器仅在发生一些移动时才更新。这是我在StackOverflow上遇到的第一个问题，对不起，如果我做错了什么。谢谢！

Answer 1

如果要定期重建窗口小部件，请添加timer_builder软件包并像这样使用它：

TimerBuilder.periodic(Duration(seconds: 1),
      builder: (context) {
        return YourWidget();
      }
)

颤振-秒表和地理定位器

1 个答案: