Question

有什么方法可以获取Flutter中两个位置之间的距离吗？

Answer 1

如果您正在寻找两个位置（即LatLng）之间最短的距离，可以使用geolocator插件。

double distanceInMeters = 
  await Geolocator().distanceBetween(52.2165157, 6.9437819, 52.3546274, 4.8285838);

Answer 2

您可以通过在镖中实现的HaverSine公式找到距离：

import'dart:math' as Math;
void main()=>print(getDistanceFromLatLonInKm(73.4545,73.4545,83.5454,83.5454));



double getDistanceFromLatLonInKm(lat1,lon1,lat2,lon2) {
  var R = 6371; // Radius of the earth in km
  var dLat = deg2rad(lat2-lat1);  // deg2rad below
  var dLon = deg2rad(lon2-lon1); 
  var a = 
    Math.sin(dLat/2) * Math.sin(dLat/2) +
    Math.cos(deg2rad(lat1)) * Math.cos(deg2rad(lat2)) * 
    Math.sin(dLon/2) * Math.sin(dLon/2)
    ; 
  var c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a)); 
  var d = R * c; // Distance in km
  return d;
}

double deg2rad(deg) {
  return deg * (Math.pi/180);
}

输出：

1139.9231530436646

Source in Javscript并归功于Chuck。

Answer 3

如果在当前位置搜索的情况下，我还使用vector_math将度数转换为弧度，还使用geolocator获得当前用户的纬度和经度可以直接通过 Geolocator.distanceBetween（startLatitude，startLongitude，endLatitude，endLongitude）来计算两个位置之间的距离。

import 'dart:math' show sin, cos, sqrt, atan2;
import 'package:vector_math/vector_math.dart';
import 'package:geolocator/geolocator.dart';

Position _currentPosition;
double earthRadius = 6371000; 

//Using pLat and pLng as dummy location
double pLat = 22.8965265;   double pLng = 76.2545445; 


//Use Geolocator to find the current location(latitude & longitude)
getUserLocation() async {
   _currentPosition = await GeoLocator.getCurrentPosition(desiredAccuracy: LocationAccuracy.high);
}

//Calculating the distance between two points without Geolocator plugin
getDistance(){
   var dLat = radians(pLat - _currentPosition.latitude);
   var dLng = radians(pLng - _currentPosition.longitude);
   var a = sin(dLat/2) * sin(dLat/2) + cos(radians(_currentPosition.latitude)) 
           * cos(radians(pLat)) * sin(dLng/2) * sin(dLng/2);
   var c = 2 * atan2(sqrt(a), sqrt(1-a));
   var d = earthRadius * c;
   print(d); //d is the distance in meters
}

//Calculating the distance between two points with Geolocator plugin
getDistance(){
   final double distance = Geolocator.distanceBetween(pLat, pLng, 
           _currentPosition.latitude, _currentPosition.longitude); 
   print(distance); //distance in meters
}

测量两个位置之间的距离

3 个答案: