Question

我有两个班级“GPSTracker”和“Live”。 GPSTracker具有GPS相关功能，即获得纬度和经度，而Live类调用它以获得当前纬度和经度，然后计算行进距离。我的问题是，我没有得到任何位置的变化，位置保持在开始时的任何东西！没有locationUpdates！

GPSTracker.java：

public class GPSTracker extends Service implements LocationListener 
{

private final Context mContext;
// flag for GPS status
boolean isGPSEnabled = false;

// flag for network status
boolean isNetworkEnabled = false;

// flag for GPS status
boolean canGetLocation = false;

Location location; // location
double latitude; // latitude
double longitude; // longitude

// The minimum distance to change Updates in meters
private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES =5; // 5 meters

// The minimum time between updates in milliseconds
private static final long MIN_TIME_BW_UPDATES = 1000 * 5; // 5 seconds

// Declaring a Location Manager
protected LocationManager locationManager;

public GPSTracker(Context context) 
{
    this.mContext = context;
    getLocation();
}

public Location getLocation() 
{
    try 
    {
        locationManager = (LocationManager) mContext
                .getSystemService(LOCATION_SERVICE);

        // getting GPS status
        isGPSEnabled = locationManager
                .isProviderEnabled(LocationManager.GPS_PROVIDER);

        // getting network status
        isNetworkEnabled = locationManager
                .isProviderEnabled(LocationManager.NETWORK_PROVIDER);

        if (!isGPSEnabled && !isNetworkEnabled) 
        {
            // no network provider is enabled
        } else 
        {
            this.canGetLocation = true;
            if (isNetworkEnabled) 
            {
                locationManager.requestLocationUpdates(
                        LocationManager.NETWORK_PROVIDER,
                        MIN_TIME_BW_UPDATES,
                        MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
                Log.d("Network", "Network");
                if (locationManager != null) 
                {
                    location = locationManager
                            .getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
                    if (location != null) 
                    {
                        latitude = location.getLatitude();
                        longitude = location.getLongitude();
                    }
                }
            }
            // if GPS Enabled get lat/long using GPS Services
            if (isGPSEnabled) 
            {
                if (location == null) 
                {
                    locationManager.requestLocationUpdates(
                            LocationManager.GPS_PROVIDER,
                            MIN_TIME_BW_UPDATES,
                            MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
                    Log.d("GPS Enabled", "GPS Enabled");
                    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;
}

/**
 * Stop using GPS listener
 * Calling this function will stop using GPS in your app
 * */
public void stopUsingGPS()
{
    if(locationManager != null)
    {
        locationManager.removeUpdates(GPSTracker.this);
    }       
}

/**
 * Function to get latitude
 * */
public double getLatitude()
{
    if(location != null)
    {
        latitude = location.getLatitude();
    }

    // return latitude
    return latitude;
}

/**
 * Function to get longitude
 * */
public double getLongitude()
{
    if(location != null)
    {
        longitude = location.getLongitude();
    }

    // return longitude
    return longitude;
}

/**
 * Function to check GPS/wifi enabled
 * @return boolean
 * */
public boolean canGetLocation() 
{
    return this.canGetLocation;
}

/**
 * Function to show settings alert dialog
 * On pressing Settings button will lauch Settings Options
 * */
public void showSettingsAlert()
{
    AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);

    // Setting Dialog Title
    alertDialog.setTitle("GPS is not enabled");

    // Setting Dialog Message
    alertDialog.setMessage("Enable location services to determine your location.");

    // On pressing Settings button
    alertDialog.setPositiveButton("Settings", new DialogInterface.OnClickListener() {
        public void onClick(DialogInterface dialog,int which) 
        {
            Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
            mContext.startActivity(intent);
        }
    });

    // on pressing cancel button
    alertDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
        public void onClick(DialogInterface dialog, int which) 
        {
        dialog.cancel();
        }
    });

    // Showing Alert Message
    alertDialog.show();
}

@Override
public void onLocationChanged(Location location) 
{

}

@Override
public void onProviderDisabled(String provider) 
{
}

@Override
public void onProviderEnabled(String provider) 
{
}

@Override
public void onStatusChanged(String provider, int status, Bundle extras) 
{
}

@Override
public IBinder onBind(Intent arg0) 
{
    return null;
}

}

Live.java：

public class Live extends Activity implements LocationListener
{   
GPSTracker gps;
Location newLocation = new Location(LocationManager.GPS_PROVIDER);
Location oldLocation = new Location(LocationManager.GPS_PROVIDER);
float distanceTravelled=0;
@Override
protected void onCreate(Bundle savedInstanceState) 
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_live);
    startactivity();

}

public void startactivity() 
{

    gps = new GPSTracker(Live.this);

    if(gps.canGetLocation())
    {
        double latitude = gps.getLatitude();
        double longitude = gps.getLongitude();
        Toast.makeText(getApplicationContext(), "Your Location is: \nLat: " + latitude + "\nLong: " + longitude, Toast.LENGTH_LONG).show();

        newLocation.setLatitude(latitude);
        newLocation.setLongitude(longitude);    
    }
    else
    {
        gps.showSettingsAlert();
    }

}

public void resumeactivity() 
{

    gps = new GPSTracker(Live.this);
    if(gps.canGetLocation())
    {
        double latitude = gps.getLatitude();
        double longitude = gps.getLongitude();
        //Toast.makeText(getApplicationContext(), "Your Location is - \nLat: " + latitude + "\nLong: " + longitude, Toast.LENGTH_LONG).show();

        newLocation.setLatitude(latitude);
        newLocation.setLongitude(longitude);
    }
    else
    {

    }
}

public void onResume() 
{
    super.onResume();
    resumeactivity();
}

@Override
public void onLocationChanged(Location location) 
{
    oldLocation.set(newLocation);
    newLocation.set(location);
    //resumeactivity();
    distanceTravelled+=newLocation.distanceTo(oldLocation);
    String stringDistance= Float.toString(distanceTravelled);
    TextView distance = (TextView) findViewById(R.id.textDistance);
    distance.setText(stringDistance);
}

@Override
public void onProviderDisabled(String arg0) 
{
    GPSTracker gps = new GPSTracker(Live.this);
    gps.showSettingsAlert();

}
@Override
public void onProviderEnabled(String arg0) 
{


}
@Override
public void onStatusChanged(String arg0, int arg1, Bundle arg2) 
{


}

Answer 1

我的应用程序遇到了同样的问题，所以我做的是重新启动手机并在晴朗的天空下启动应用程序。它可能会对你有帮助。

Answer 2

您可以找到一个有效的例子here。它不是计算距离，但这应该很容易添加。

未在Android中收到位置更新

2 个答案: