Question

我正在尝试创建一个从用户的gps中获取经度和经度的应用程序，这是我正在使用的类： -

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 = 10; // 10 meters

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

// 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;
            // First get location from Network Provider
            if (isNetworkEnabled) {
                if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
                    // TODO: Consider calling
                    //    ActivityCompat#requestPermissions
                    // here to request the missing permissions, and then overriding
                    //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
                    //                                          int[] grantResults)
                    // to handle the case where the user grants the permission. See the documentation
                    // for ActivityCompat#requestPermissions for more details.
                    //return TODO;
                    Toast.makeText(this,"It's very important that you agree to gps permission, kindly restart the app and accept",Toast.LENGTH_LONG).show();

                }
                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;
}

当我在MainActivity中调用此函数时，它永远不会要求任何权限，也不会显示任何错误，这是我正在使用的函数： -

String getlocurl(){
    GPSTracker gps;
    gps = new GPSTracker(MainActivity.this);
    double latitude = 0;
    double longitude = 0;
    if(gps.canGetLocation()){
        latitude = gps.getLatitude();
        longitude = gps.getLongitude();
        String lat = String.valueOf(latitude);
        String lng = String.valueOf(longitude);
        String mapurl = "https://www.google.com/maps/preview/@"+lat+","+lng+","+"8z";
        return mapurl;
    }
    else{
        // can't get location
        // GPS or Network is not enabled
        // Ask user to enable GPS/network in settings
        gps.showSettingsAlert();
        return "error";
    }


}

这是我得到的结果：“https://www.google.com/maps/preview/@0.0,0.0,8z” 它返回0.0,0.0作为纬度和经度，我该如何解决这个问题？

Answer 1

将它放在application标记之前的清单文件中：

<uses-permission android:name="android.permission.INTERNET" />                  <!-- verify if connected to the internet -->
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />      <!-- verify if connected to any network -->
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />      <!-- verify location using GPS, give precise location -->
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />    <!-- verify location using WiFi and mobile, gives approximate location -->

无法从gps获取位置

1 个答案: