Location Manager remove updates permission

问题:

I am using android studio and compileSdkVersion is 23 in that i am using below code

 if(locationManager != null){
            locationManager.removeUpdates(GPSListener.this);
        }

to stop gps update where GPS Listener is a class which implements LocationListener.

but in removeUpdates line i am getting below lint warning

Call requires permission which may be rejected by user: code should explicitly check to see if permission is available (with checkPermission) or handle a potential SecurityException

I am not getting what is the issue in the above code. Any extra permission need to be added in manifest file?.

Regards.

回答1:

Since SDK 23, you should/need to check the permission before you call Location API functionality. Here is an example of how to do it:

if (locationManager != null) {
    if (checkSelfPermission(Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED
            || checkSelfPermission(Manifest.permission.ACCESS_COARSE_LOCATION) == PackageManager.PERMISSION_GRANTED) {
        locationManager.removeUpdates(GPSListener.this);
    }
}

There is checkSelfPermission(), which is to check if 'you' (this app) has the correct permissions. There is also checkPermission(), which is to check if another process has the correct permissions.

Notes

• next to doing this runtime check, it is still also necessary to require the relevant permissions in the AndroidManifest.
• if your targetSdk is < 23, you should use ContextCompat.checkSelfPermission() instead (thanks to JerryBrady)

回答2:

I wasn't able to use checkSelfPermission(), because my min API is 14 and 23 is required. Knowing that, you can also try to catch a SecurityException.

Example:

try {
    locationManager.removeUpdates(GPSListener.this);
} catch (SecurityException e) {
    Log.e("PERMISSION_EXCEPTION","PERMISSION_NOT_GRANTED");
}

回答3:

To add to Jerry Brady's comment regarding ContextCompat, this is be the full code for < 23:

 if (ContextCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED
                || ContextCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_COARSE_LOCATION) == PackageManager.PERMISSION_GRANTED)

回答4:

Here is my solution !

  if (Build.VERSION.SDK_INT >= 23) {

                if (checkSelfPermission(android.Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED
                        || checkSelfPermission(android.Manifest.permission.ACCESS_COARSE_LOCATION) == PackageManager.PERMISSION_GRANTED) {

                    lm.removeUpdates(this);
                }
            }
            else
            {
                lm.removeUpdates(this);

            }