我正致力于使用lat和long找到2点之间的距离。
我已遵循这些守则。
/* double theta = lon1 - lon2;
double dist = Math.sin(deg2rad(lat1)) * Math.sin(deg2rad(lat2)) + Math.cos(deg2rad(lat1)) * Math.cos(deg2rad(lat2)) * Math.cos(deg2rad(theta));
dist = Math.acos(dist);
dist = rad2deg(dist);
dist = dist * 60 * 1.1515;
return (dist);*/
Log.e("distancefinder","Past lat: "+lat1);
Log.e("distancefinder","Past long: "+lon1);
Log.e("distancefinder","current lat : "+lat2);
Log.e("distancefinder","current long : "+lon2);
int R = 6371; // km
double dLat = toRadians(lat2-lat1);
double dLon = toRadians(lon2-lon1);
lat1 = toRadians(lat1);
lat2 = toRadians(lat2);
double a = Math.sin(dLat/2) * Math.sin(dLat/2) +
Math.sin(dLon/2) * Math.sin(dLon/2) * Math.cos(lat1) * Math.cos(lat2);
double c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a));
return R * c;
/* double earthRadius = 6371000; //meters
double dLat = Math.toRadians(lat2-lat1);
double dLng = Math.toRadians(lon2-lon1);
double a = Math.sin(dLat/2) * Math.sin(dLat/2) +
Math.cos(Math.toRadians(lat1)) *
Math.cos(Math.toRadians(lat2)) *
Math.sin(dLng/2) * Math.sin(dLng/2);
double c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a));
float dist = (float) (earthRadius * c);
return dist;*/
/* double distance;
Location locationA = new Location("");
locationA.setLatitude(lat1);
locationA.setLongitude(lon1);
Location locationB = new Location("");
locationB.setLatitude(lat2);
locationB.setLongitude(lon2);
distance = locationA.distanceTo(locationB); //in meters
return distance;*/
// distance = locationA.distanceTo(locationB)/1000; //in km
11-20 12:28:15.621: E/distancefinder(5309): compare lat and long
11-20 12:28:15.621: E/distancefinder(5309): Same latitude and longtitude and return false
11-20 12:28:25.384: E/distancefinder(5592): compare lat and long
11-20 12:28:25.384: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:28:30.380: E/distancefinder(5592): compare lat and long
11-20 12:28:30.381: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:28:35.404: E/distancefinder(5592): compare lat and long
11-20 12:28:35.404: E/distancefinder(5592): Past lat: 12.9876692
11-20 12:28:35.404: E/distancefinder(5592): Past long: 77.5950608
11-20 12:28:35.404: E/distancefinder(5592): current lat : 12.9876766
11-20 12:28:35.404: E/distancefinder(5592): current long : 77.5950719
11-20 12:28:35.404: E/distancefinder(5592): Distance in km :0.0014572341093100844
11-20 12:28:35.417: E/distancefinder(5592): Distance in mts : 1.4572341093100845
11-20 12:28:40.399: E/distancefinder(5592): compare lat and long
11-20 12:28:40.399: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:28:45.403: E/distancefinder(5592): compare lat and long
11-20 12:28:45.403: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:28:50.412: E/distancefinder(5592): compare lat and long
11-20 12:28:50.412: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:28:55.398: E/distancefinder(5592): compare lat and long
11-20 12:28:55.398: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:29:00.381: E/distancefinder(5592): compare lat and long
11-20 12:29:00.381: E/distancefinder(5592): Past lat: 12.9876766
11-20 12:29:00.381: E/distancefinder(5592): Past long: 77.5950719
11-20 12:29:00.381: E/distancefinder(5592): current lat : 12.9876807
11-20 12:29:00.381: E/distancefinder(5592): current long : 77.5950323
11-20 12:29:00.382: E/distancefinder(5592): Distance in km :0.004314827685750207
11-20 12:29:00.387: E/distancefinder(5592): Distance in mts : 4.314827685750207
11-20 12:29:05.407: E/distancefinder(5592): compare lat and long
11-20 12:29:05.407: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:29:10.408: E/distancefinder(5592): compare lat and long
11-20 12:29:10.408: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:29:15.401: E/distancefinder(5592): compare lat and long
11-20 12:29:15.401: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:29:20.405: E/distancefinder(5592): compare lat and long
11-20 12:29:20.405: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:29:25.386: E/distancefinder(5592): compare lat and long
11-20 12:29:25.386: E/distancefinder(5592): Past lat: 12.9876807
11-20 12:29:25.386: E/distancefinder(5592): Past long: 77.5950323
11-20 12:29:25.386: E/distancefinder(5592): current lat : 12.9876729
11-20 12:29:25.386: E/distancefinder(5592): current long : 77.5950339
11-20 12:29:25.387: E/distancefinder(5592): Distance in km :8.844764712143432E-4
11-20 12:29:25.396: E/distancefinder(5592): Distance in mts : 0.8844764712143431
11-20 12:29:30.392: E/distancefinder(5592): compare lat and long
11-20 12:29:30.392: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:29:35.393: E/distancefinder(5592): compare lat and long
11-20 12:29:35.393: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:29:40.401: E/distancefinder(5592): compare lat and long
11-20 12:29:40.402: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:29:45.386: E/distancefinder(5592): compare lat and long
11-20 12:29:45.386: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:29:50.403: E/distancefinder(5592): compare lat and long
11-20 12:29:50.403: E/distancefinder(5592): Past lat: 12.9876729
11-20 12:29:50.403: E/distancefinder(5592): Past long: 77.5950339
11-20 12:29:50.403: E/distancefinder(5592): current lat : 12.9876932
11-20 12:29:50.403: E/distancefinder(5592): current long : 77.5950936
11-20 12:29:50.403: E/distancefinder(5592): Distance in km :0.0068510533659564225
11-20 12:29:50.418: E/distancefinder(5592): Distance in mts : 6.851053365956423
11-20 12:29:55.404: E/distancefinder(5592): compare lat and long
11-20 12:29:55.404: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:30:00.401: E/distancefinder(5592): compare lat and long
11-20 12:30:00.401: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:30:05.381: E/distancefinder(5592): compare lat and long
11-20 12:30:05.381: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:30:10.419: E/distancefinder(5592): compare lat and long
11-20 12:30:10.419: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:30:15.386: E/distancefinder(5592): compare lat and long
11-20 12:30:15.387: E/distancefinder(5592): Past lat: 12.9876932
11-20 12:30:15.387: E/distancefinder(5592): Past long: 77.5950936
11-20 12:30:15.387: E/distancefinder(5592): current lat : 12.9876918
11-20 12:30:15.387: E/distancefinder(5592): current long : 77.5950864
11-20 12:30:15.387: E/distancefinder(5592): Distance in km :7.955033100235504E-4
11-20 12:30:15.394: E/distancefinder(5592): Distance in mts : 0.7955033100235503
11-20 12:30:20.373: E/distancefinder(5592): compare lat and long
11-20 12:30:20.373: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:30:25.401: E/distancefinder(5592): compare lat and long
11-20 12:30:25.401: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:30:30.411: E/distancefinder(5592): compare lat and long
11-20 12:30:30.411: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:30:35.391: E/distancefinder(5592): compare lat and long
11-20 12:30:35.391: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:30:40.383: E/distancefinder(5592): compare lat and long
11-20 12:30:40.384: E/distancefinder(5592): Past lat: 12.9876918
11-20 12:30:40.384: E/distancefinder(5592): Past long: 77.5950864
11-20 12:30:40.384: E/distancefinder(5592): current lat : 12.9876826
11-20 12:30:40.384: E/distancefinder(5592): current long : 77.5950311
11-20 12:30:40.384: E/distancefinder(5592): Distance in km :0.006078478068578999
11-20 12:30:40.392: E/distancefinder(5592): Distance in mts : 6.078478068578999
11-20 12:30:45.532: E/distancefinder(5592): compare lat and long
11-20 12:30:45.532: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:30:50.402: E/distancefinder(5592): compare lat and long
11-20 12:30:50.402: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:30:55.412: E/distancefinder(5592): compare lat and long
11-20 12:30:55.412: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:31:00.409: E/distancefinder(5592): compare lat and long
11-20 12:31:00.409: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:31:05.387: E/distancefinder(5592): compare lat and long
11-20 12:31:05.387: E/distancefinder(5592): Past lat: 12.9876826
11-20 12:31:05.387: E/distancefinder(5592): Past long: 77.5950311
11-20 12:31:05.387: E/distancefinder(5592): current lat : 12.987683
11-20 12:31:05.387: E/distancefinder(5592): current long : 77.5950143
11-20 12:31:05.388: E/distancefinder(5592): Distance in km :0.0018208297478854096
11-20 12:31:05.395: E/distancefinder(5592): Distance in mts : 1.8208297478854096
11-20 12:31:10.399: E/distancefinder(5592): compare lat and long
11-20 12:31:10.399: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:31:15.405: E/distancefinder(5592): compare lat and long
11-20 12:31:15.405: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:31:20.405: E/distancefinder(5592): compare lat and long
11-20 12:31:20.405: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:31:25.411: E/distancefinder(5592): compare lat and long
11-20 12:31:25.418: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:31:30.409: E/distancefinder(5592): compare lat and long
11-20 12:31:30.409: E/distancefinder(5592): Past lat: 12.987683
11-20 12:31:30.409: E/distancefinder(5592): Past long: 77.5950143
11-20 12:31:30.409: E/distancefinder(5592): current lat : 12.9876792
11-20 12:31:30.409: E/distancefinder(5592): current long : 77.5950169
11-20 12:31:30.409: E/distancefinder(5592): Distance in km :5.078402770198048E-4
11-20 12:31:30.423: E/distancefinder(5592): Distance in mts : 0.5078402770198048
11-20 12:31:35.410: E/distancefinder(5592): compare lat and long
11-20 12:31:35.410: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:31:40.405: E/distancefinder(5592): compare lat and long
11-20 12:31:40.405: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:31:45.395: E/distancefinder(5592): compare lat and long
11-20 12:31:45.395: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:31:50.407: E/distancefinder(5592): compare lat and long
11-20 12:31:50.407: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:31:55.399: E/distancefinder(5592): compare lat and long
11-20 12:31:55.399: E/distancefinder(5592): Past lat: 12.9876792
11-20 12:31:55.399: E/distancefinder(5592): Past long: 77.5950169
11-20 12:31:55.399: E/distancefinder(5592): current lat : 12.9876777
11-20 12:31:55.399: E/distancefinder(5592): current long : 77.5950228
11-20 12:31:55.399: E/distancefinder(5592): Distance in km :6.606681020544278E-4
11-20 12:31:55.414: E/distancefinder(5592): Distance in mts : 0.6606681020544278
11-20 12:32:00.404: E/distancefinder(5592): compare lat and long
11-20 12:32:00.404: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:32:05.404: E/distancefinder(5592): compare lat and long
11-20 12:32:05.404: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:32:10.418: E/distancefinder(5592): compare lat and long
11-20 12:32:10.418: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:32:15.414: E/distancefinder(5592): compare lat and long
11-20 12:32:15.414: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:32:20.392: E/distancefinder(5592): compare lat and long
11-20 12:32:20.392: E/distancefinder(5592): Past lat: 12.9876777
11-20 12:32:20.392: E/distancefinder(5592): Past long: 77.5950228
11-20 12:32:20.392: E/distancefinder(5592): current lat : 12.9876642
11-20 12:32:20.392: E/distancefinder(5592): current long : 77.5950319
11-20 12:32:20.393: E/distancefinder(5592): Distance in km :0.0017959869680722845
11-20 12:32:20.403: E/distancefinder(5592): Distance in mts : 1.7959869680722844
11-20 12:32:25.410: E/distancefinder(5592): compare lat and long
11-20 12:32:25.410: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:32:30.409: E/distancefinder(5592): compare lat and long
11-20 12:32:30.410: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:32:35.399: E/distancefinder(5592): compare lat and long
11-20 12:32:35.399: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:32:40.403: E/distancefinder(5592): compare lat and long
11-20 12:32:40.403: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:32:45.412: E/distancefinder(5592): compare lat and long
11-20 12:32:45.412: E/distancefinder(5592): Past lat: 12.9876642
11-20 12:32:45.412: E/distancefinder(5592): Past long: 77.5950319
11-20 12:32:45.412: E/distancefinder(5592): current lat : 12.9876828
11-20 12:32:45.412: E/distancefinder(5592): current long : 77.5950043
11-20 12:32:45.413: E/distancefinder(5592): Distance in km :0.0036359967167283705
11-20 12:32:45.425: E/distancefinder(5592): Distance in mts : 3.6359967167283704
11-20 12:32:50.435: E/distancefinder(5592): compare lat and long
11-20 12:32:50.435: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:32:55.420: E/distancefinder(5592): compare lat and long
11-20 12:32:55.420: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:33:00.405: E/distancefinder(5592): compare lat and long
11-20 12:33:00.405: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:33:05.407: E/distancefinder(5592): compare lat and long
11-20 12:33:05.407: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:33:10.410: E/distancefinder(5592): compare lat and long
11-20 12:33:10.411: E/distancefinder(5592): Past lat: 12.9876828
11-20 12:33:10.411: E/distancefinder(5592): Past long: 77.5950043
11-20 12:33:10.411: E/distancefinder(5592): current lat : 12.9876684
11-20 12:33:10.411: E/distancefinder(5592): current long : 77.5950334
11-20 12:33:10.411: E/distancefinder(5592): Distance in km :0.0035362761324678593
11-20 12:33:10.419: E/distancefinder(5592): Distance in mts : 3.5362761324678593
11-20 12:33:15.411: E/distancefinder(5592): compare lat and long
11-20 12:33:15.411: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:33:20.392: E/distancefinder(5592): compare lat and long
11-20 12:33:20.393: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:33:25.408: E/distancefinder(5592): compare lat and long
11-20 12:33:25.408: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:33:30.427: E/distancefinder(5592): compare lat and long
11-20 12:33:30.427: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:33:35.387: E/distancefinder(5592): compare lat and long
11-20 12:33:35.388: E/distancefinder(5592): Past lat: 12.9876684
11-20 12:33:35.388: E/distancefinder(5592): Past long: 77.5950334
11-20 12:33:35.388: E/distancefinder(5592): current lat : 12.9876785
11-20 12:33:35.388: E/distancefinder(5592): current long : 77.5950269
11-20 12:33:35.388: E/distancefinder(5592): Distance in km :0.0013256282494112776
11-20 12:33:35.397: E/distancefinder(5592): Distance in mts : 1.3256282494112777
11-20 12:33:40.408: E/distancefinder(5592): compare lat and long
11-20 12:33:40.408: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:33:45.410: E/distancefinder(5592): compare lat and long
11-20 12:33:45.410: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:33:50.413: E/distancefinder(5592): compare lat and long
11-20 12:33:50.413: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:33:55.416: E/distancefinder(5592): compare lat and long
11-20 12:33:55.416: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:34:00.412: E/distancefinder(5592): compare lat and long
11-20 12:34:00.412: E/distancefinder(5592): Past lat: 12.9876785
11-20 12:34:00.412: E/distancefinder(5592): Past long: 77.5950269
11-20 12:34:00.414: E/distancefinder(5592): current lat : 12.9876793
11-20 12:34:00.414: E/distancefinder(5592): current long : 77.595028
11-20 12:34:00.414: E/distancefinder(5592): Distance in km :1.4872230719746918E-4
11-20 12:34:00.425: E/distancefinder(5592): Distance in mts : 0.14872230719746918
11-20 12:34:05.417: E/distancefinder(5592): compare lat and long
11-20 12:34:05.417: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:34:10.408: E/distancefinder(5592): compare lat and long
11-20 12:34:10.410: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:34:15.411: E/distancefinder(5592): compare lat and long
11-20 12:34:15.411: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:34:20.408: E/distancefinder(5592): compare lat and long
11-20 12:34:20.408: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:34:25.388: E/distancefinder(5592): compare lat and long
11-20 12:34:25.388: E/distancefinder(5592): Past lat: 12.9876793
11-20 12:34:25.388: E/distancefinder(5592): Past long: 77.595028
11-20 12:34:25.388: E/distancefinder(5592): current lat : 12.9876759
11-20 12:34:25.388: E/distancefinder(5592): current long : 77.5950243
11-20 12:34:25.388: E/distancefinder(5592): Distance in km :5.510439055217952E-4
11-20 12:34:25.395: E/distancefinder(5592): Distance in mts : 0.5510439055217952
11-20 12:34:30.415: E/distancefinder(5592): compare lat and long
11-20 12:34:30.415: E/distancefinder(5592): Same latitude and longtitude and return false
11-20 12:34:35.412: E/distancefinder(5592): compare lat and long
11-20 12:34:35.412: E/distancefinder(5592): Same latitude and longtitude and return false
那么，解决方案是什么呢？请帮我解决这个问题。
答案 0 :(得分：0)
使用以下方法计算两个lang lng的距离b / w。
public static float calculateDistanceBetweenTwoPoints(Double latitude, Double longitude, Double toLat, Double toLng){
float[] results = new float[2];
Location.distanceBetween(latitude, longitude, toLat, toLng, results);
float distanceInMeters = results[0];
return distanceInMeters;
}
答案 1 :(得分：0)
package com.remo.distancefinder;
import java.util.Timer;
import java.util.TimerTask;
import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.location.Location;
import android.os.Handler;
import android.os.IBinder;
import android.util.Log;
import android.widget.Toast;
public class GPSservice extends Service{
private Context main_context;
private GPSTracker gpsTracker;
private Handler handler= new Handler();
private Timer timer = new Timer();
private Distance pastDistance = new Distance();
private Distance currentDistance = new Distance();
public static double DISTANCE;
boolean flag = true ;
private double totalDistance ;
@Override
public IBinder onBind(Intent intent) {
// TODO Auto-generated method stub
return null;
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
// TODO Auto-generated method stub
Log.e("distancefinder","service started");
main_context = getApplicationContext();
gpsTracker = new GPSTracker(main_context);
pastDistance.setLatitude(gpsTracker.getLocation().getLatitude());
pastDistance.setLongitude(gpsTracker.getLocation().getLongitude());
TimerTask timerTask = new TimerTask() {
@Override
public void run() {
handler.post(new Runnable() {
@Override
public void run() {
currentDistance.setLatitude(gpsTracker.getLocation().getLatitude());
currentDistance.setLongitude(gpsTracker.getLocation().getLongitude());
Toast.makeText(main_context, "latitude:"+gpsTracker.getLocation().getLatitude()+
"Longitude:"+gpsTracker.getLocation().getLongitude(), Toast.LENGTH_SHORT).show();
comapre_LatitudeLongitude();
/* if(flag){
pastDistance.setLatitude(gpsTracker.getLocation().getLatitude());
pastDistance.setLongitude(gpsTracker.getLocation().getLongitude());
flag = false;
}else{
Log.e("distancefinder","In else statement");
currentDistance.setLatitude(gpsTracker.getLocation().getLatitude());
currentDistance.setLongitude(gpsTracker.getLocation().getLongitude());
flag = comapre_LatitudeLongitude();
}*/
}
});
}
};
timer.schedule(timerTask,0, 5000);
return super.onStartCommand(intent, flags, startId);
}
/* private double distance(double lat1, double lon1, double lat2, double lon2) {
double theta = lon1 - lon2;
double dist = Math.sin(deg2rad(lat1)) * Math.sin(deg2rad(lat2)) + Math.cos(deg2rad(lat1)) * Math.cos(deg2rad(lat2)) * Math.cos(deg2rad(theta));
dist = Math.acos(dist);
dist = rad2deg(dist);
dist = dist * 60 * 1.1515;
return (dist);
Log.e("distancefinder","Past lat: "+lat1);
Log.e("distancefinder","Past long: "+lon1);
Log.e("distancefinder","current lat : "+lat2);
Log.e("distancefinder","current long : "+lon2);
int R = 6371; // km
double dLat = toRadians(lat2-lat1);
double dLon = toRadians(lon2-lon1);
lat1 = toRadians(lat1);
lat2 = toRadians(lat2);
double a = Math.sin(dLat/2) * Math.sin(dLat/2) +
Math.sin(dLon/2) * Math.sin(dLon/2) * Math.cos(lat1) * Math.cos(lat2);
double c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a));
return R * c;
double earthRadius = 6371000; //meters
double dLat = Math.toRadians(lat2-lat1);
double dLng = Math.toRadians(lon2-lon1);
double a = Math.sin(dLat/2) * Math.sin(dLat/2) +
Math.cos(Math.toRadians(lat1)) *
Math.cos(Math.toRadians(lat2)) *
Math.sin(dLng/2) * Math.sin(dLng/2);
double c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a));
float dist = (float) (earthRadius * c);
return dist;
double distance;
Location locationA = new Location("");
locationA.setLatitude(lat1);
locationA.setLongitude(lon1);
Location locationB = new Location("");
locationB.setLatitude(lat2);
locationB.setLongitude(lon2);
distance = locationA.distanceTo(locationB); //in meters
return distance;
// distance = locationA.distanceTo(locationB)/1000; //in km
}
public double toRadians(double deg) {
return deg * (Math.PI/180);
}
private double deg2rad(double deg) {
return (deg * Math.PI / 180.0);
}
private double rad2deg(double rad) {
return (rad * 180.0 / Math.PI);
}*/
public float distFrom(float lat1, float lng1, float lat2, float lng2) {
Log.e("distancefinder","Past lat: "+lat1);
Log.e("distancefinder","Past long: "+lng1);
Log.e("distancefinder","current lat : "+lat2);
Log.e("distancefinder","current long : "+lng2);
double earthRadius = 6371000; //meters
double dLat = Math.toRadians(lat2-lat1);
double dLng = Math.toRadians(lng2-lng1);
double a = Math.sin(dLat/2) * Math.sin(dLat/2) +
Math.cos(Math.toRadians(lat1)) * Math.cos(Math.toRadians(lat2)) *
Math.sin(dLng/2) * Math.sin(dLng/2);
double c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a));
float dist = (float) (earthRadius * c);
return dist;
}
@Override
public void onDestroy() {
super.onDestroy();
System.out.println("--------------------------------onDestroy -stop service ");
timer.cancel();
DISTANCE = totalDistance ;
}
public void comapre_LatitudeLongitude(){
Log.e("distancefinder","compare lat and long");
if(pastDistance.getLatitude() == currentDistance.getLatitude() && pastDistance.getLongitude() == currentDistance.getLongitude()){
Log.e("distancefinder","Same latitude and longtitude and return false");
// return false;
}else{
final double distance = distFrom((float)pastDistance.getLatitude(),(float)pastDistance.getLongitude(),(float)currentDistance.getLatitude(),(float)currentDistance.getLongitude());
Log.e("distancefinder","Distance in km :"+distance);
handler.post(new Runnable() {
@Override
public void run() {
/*float kilometer=1.609344f;
Log.e("distancefinder","Total distance initial"+distance);
totalDistance = totalDistance + distance * kilometer*/;
//DISTANCE = distance;
pastDistance.setLatitude(currentDistance.getLatitude());
pastDistance.setLongitude(currentDistance.getLongitude());
Log.e("distancefinder"," Distance in mts : "+distance);
Toast.makeText(main_context, "distance in mtrs:"+distance, Toast.LENGTH_SHORT).show();
}
});
// return true;
}
}
}
答案 2 :(得分：0)
您获取double a的计算看起来有误，而且我不确定您使用toRadians()做了什么（这是一种方法还是应该是Math.toRadians()？）。我使用下面的方法，它没有问题（返回距离，以千米为单位，但你可以将其改为你需要的任何东西）。
public static double getDistance(double deviceLatitude, double deviceLongitude,
double destinationLatitude, double destinationLongitude) {
double distanceLatitude = Math.toRadians(deviceLatitude - destinationLatitude);
double distanceLongitude = Math.toRadians(deviceLongitude - destinationLongitude);
double a = Math.sin(distanceLatitude / 2)
* Math.sin(distanceLatitude / 2)
+ Math.cos(Math.toRadians(destinationLatitude))
* Math.cos(Math.toRadians(deviceLatitude))
* Math.sin(distanceLongitude / 2)
* Math.sin(distanceLongitude / 2);
double c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));
return Double.valueOf(new DecimalFormat("#.#").format(6371 * c));
}
答案 3 :(得分：0)
如果您使用的是谷歌地图V2 API，则可以使用以下代码来获得准确的结果 //说你有
LatLng latLong1,latLong2;
latLong1=new LatLng(12.77, 77.88);
latLong2=new LatLng(17.77, 74.88);
//Convert latLong to location object
Location location1=new Location("location1");
location1.setLongitude(latLong1.latitude);
location1.setLongitude(latLong1.longitude);
Location location2=new Location("location2");
location2.setLongitude(latLong2.latitude);
location2.setLongitude(latLong2.longitude);
float distanceInMeters= location1.distanceTo(location2);
希望这有帮助