我正在制作应用程序，我使用GPS和计算行进距离，我正在下载当前的loaction和计算两个位置之间的距离。当我想要获取当前位置时，它显示我不同的位置（我不移动我的手机），当我试图计算距离时，我发现错误的结果：/这里的源代码
GPSTracker：
public class GPSTracker extends Service implements LocationListener {
private final Context mContext;
public static double distance=0;
Location location1,location2;
boolean isGPSEnabled = false;
boolean isNetworkEnabled = false;
boolean canGetLocation = false;
Activity activity;
Location location;
double latitude;
double longitude;
private static final float MIN_DISTANCE_CHANGE_FOR_UPDATES = 50;
private static final long MIN_TIME_BW_UPDATES = 1000 * 10;
protected LocationManager locationManager;
public GPSTracker(Context context, Activity activity) {
this.mContext = context;
this.activity = activity;
getLocation();
}
public Location getLocation() {
try {
locationManager = (LocationManager) mContext.getSystemService(LOCATION_SERVICE);
isGPSEnabled = locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);
isNetworkEnabled = locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
if (!isGPSEnabled && !isNetworkEnabled) {
} else {
this.canGetLocation = true;
if (isNetworkEnabled) {
int requestPermissionsCode = 50;
if (ContextCompat.checkSelfPermission(activity, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(activity, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(activity, new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, requestPermissionsCode);
} else {
locationManager.requestLocationUpdates(
LocationManager.NETWORK_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, mLocationListener);
if (locationManager != null) {
location = locationManager
.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
}
if(isGPSEnabled) {
if(location == null) {
if (ContextCompat.checkSelfPermission(activity, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(activity, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(activity, new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, 50);
} else {
locationManager.requestLocationUpdates(
LocationManager.GPS_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, mLocationListener);
if (locationManager != null) {
location = locationManager
.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
}
}
}
} catch (Exception e){
e.printStackTrace();
}
return location;
}
private final LocationListener mLocationListener = new LocationListener() {
@Override
public void onLocationChanged(Location location) {
if(location != null){
latitude = location.getLatitude();
longitude = location.getLongitude();
}
if(location1 == null){
location1 = location;
} else {
location2 = location1;
location1 = location;
distance += location1.distanceTo(location2) / 1000f;
}
}
@Override
public void onStatusChanged(String s, int i, Bundle bundle) {
}
@Override
public void onProviderEnabled(String s) {
}
@Override
public void onProviderDisabled(String s) {
}
};
public double getLatitude(){
if(location != null){
latitude = location.getLatitude();
}
// return latitude
return latitude;
}
public double getLongitude(){
if(location != null){
longitude = location.getLongitude();
}
// return longitude
return longitude;
}
public boolean canGetLocation() {
return this.canGetLocation;
}
@Nullable
@Override
public IBinder onBind(Intent intent) {
return null;
}
@Override
public void onLocationChanged(Location location) {
}
@Override
public void onStatusChanged(String s, int i, Bundle bundle) {
}
@Override
public void onProviderEnabled(String s) {
}
@Override
public void onProviderDisabled(String s) {
}
}
DistanceActivity：
public class DistanceActivity extends Activity{
Button startB, stopB;
TextView textView;
GPSTracker gps;
Context mContext;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_distance);
startB = findViewById(R.id.start_B);
stopB = findViewById(R.id.stop_B);
textView = findViewById(R.id.distance_TV);
mContext = this;
startB.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
gps = new GPSTracker(mContext,DistanceActivity.this);
if(gps.canGetLocation()){
textView.setText("Distance: "+String.format("%.2f Km",gps.distance ));
} else {
textView.setText("Cannot count distance.");
}
}
});
}
}