首先,您的代码未编译
其次,将全局状态与异步调用一起使用。如果仅将参数传递给getDistance方法,那会更好。像这样:
Future<double> getDistance(double lat, double long) async {
final distanceInMeters = await Geolocator().distanceBetween(
currentLocation.latitude,
currentLocation.longitude,
lat,
lng
);
return distanceInMeters / 1000;
}
最后,您应该使用FutureBuilder调用getDistance
:
ListView.separated(
itemCount: content.length,
separatorBuilder: (context, position) {
// return a separator widget;
},
itemBuilder: (context, position) {
final current = content[position];
return FutureBuilder<String>(
future: getDistance(current.lat, current.long)
.then((value) => value.toString()),
builder: (context, snapshot) {
return Container(
child: Column(
children: <Widget>[new Text(snapshot.data)],
),
);
});
});