安装应用程序上的 Android getLocation 为 0.0

Posted 2023-04-14

【中文标题】安装应用程序上的 Android getLocation 为 0.0

【英文标题】：Android getLocation on install app is 0.0

【发布时间】：2017-04-09 05:28:15

【问题描述】：

我在真实设备中测试我的应用程序，但出现错误并且不知道如何修复。

我的应用程序在安装应用程序时要求允许访问 android 上的位置。 首次定位需要点击定位按钮。

我的问题是：如果 GPS 被禁用，应用程序找不到正确的位置，即使在激活后，得到纬度和经度 0.0。

当您单击按钮时，应用程序会检查它是否已激活并要求激活，但即使激活位置也与 0.0 相同

如果您在启用 GPS 的情况下安装应用程序，则不会出现此问题。

有人可以帮我吗？

我使用此代码定位按钮

 public void btnlocalizacao(View view) 
       gps = new GPSTracker(MainActivity.this);

    // check if GPS enabled
                if (gps.canGetLocation()) 
                    double latitude = gps.getLatitude();
                    double longitude = gps.getLongitude();
                    CameraPosition newCamPos = new CameraPosition(new LatLng(latitude, longitude),
                            15.5f,
                            googleMap.getCameraPosition().tilt, //use old tilt
                            googleMap.getCameraPosition().bearing); //use old bearing
                    googleMap.animateCamera(CameraUpdateFactory.newCameraPosition(newCamPos), 2000, null);

                 else 
                    gps.showSettingsAlert();
                

这是 gps 类

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 = 1; // 10 meters

    // The minimum time between updates in milliseconds
    private static final long MIN_TIME_BW_UPDATES = 1000 * 60 ; // 1 minute

    // Declaring a Location Manager
    protected LocationManager locationManager;
    Criteria criteria = new Criteria();

    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;
                // First get location from Network Provider
                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.getBestProvider(criteria, true));
                        //location = locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
                        if (location != null) 
                            latitude = location.getLatitude();
                            longitude = location.getLongitude();
                            Log.d("Localização", latitude + " " + longitude);
                        
                    
                
                // 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.getBestProvider(criteria, false));
                            //location = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
                            if (location != null) 
                                latitude = location.getLatitude();
                                longitude = location.getLongitude();
                                Log.d("Localização", latitude + " " + longitude);
                            
                        
                    
                
            

         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("ALerta de GPS");

        // Setting Dialog Message
        alertDialog.setMessage("GPS não esta ativado, gostaria de ativar?");

        // On pressing Settings button
        alertDialog.setPositiveButton("Configurações", 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("Cancelar", 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;
    

【参考方案1】：

我的问题是：如果 GPS 被禁用，应用程序找不到正确的位置，即使在激活后，得到纬度和经度 0.0。

一切都按预期进行。您被授予位置许可这一事实意味着您被允许获取位置如果且仅当可用时。仅此而已，尤其是它不保证甚至不意味着您将永远从系统中获得任何坐标（用户可能即根本不使用 GPS 接收器）。

【讨论】：

但是如果启用了 GPS 为什么不会出现这种情况？

因为启用了 GPS。