Calling WifiManager.startLocalOnlyHotspot() throws SecurityException even after granting all required permissions on some devices

问题

I am working on a file sharing app. I need to turn on local only hotspot of a device programmatically by calling WifiManager.startLocalOnlyHotspot().

According to the android docs on this page - https://developer.android.com/reference/android/net/wifi/WifiManager#startLocalOnlyHotspot(android.net.wifi.WifiManager.LocalOnlyHotspotCallback,%2520android.os.Handler),

Applications need to have the following permissions to start LocalOnlyHotspot: Manifest.permission.CHANGE_WIFI_STATE and ACCESS_FINE_LOCATION. Callers without the permissions will trigger a SecurityException.

I have added both these permissions in my manifest and also granted ACCESS_FINE_LOCATION at runtime (coz it's a runtime permission (dangerous permission)).

But calling startLocalOnlyHotspot() still throws SecurityException in some devices.
Device in which SecurityException is thrown: Samsung Galaxy J7 Max (j7maxlte), Android 8.1 Device in which it works fine without throwing an exception: Redmi Note 7 Pro, Android 9 PKQ1.181203.001

What am I missing?

回答1:

You need to enable location using GPS.

First of all, add the dependency for gms.

implementation 'com.google.android.gms:play-services-location:16.0.0'

After that, set up Location Services

  private void setupLocationServices() {
    LocationRequest mLocationRequest = new LocationRequest();
    mLocationRequest.setInterval(10);
    mLocationRequest.setSmallestDisplacement(10);
    mLocationRequest.setFastestInterval(10);
    mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
    LocationSettingsRequest.Builder builder = new
        LocationSettingsRequest.Builder();
    builder.addLocationRequest(mLocationRequest);

    task = LocationServices.getSettingsClient(this).checkLocationSettings(builder.build());

    locationSettingsResponseBuilder();
  }

LocationSettingsResponseBuilder:

  private void locationSettingsResponseBuilder() {
    task.addOnCompleteListener(task -> {
      try {
        LocationSettingsResponse response = task.getResult(ApiException.class);
        // All location settings are satisfied. The client can initialize location
        // requests here.

        //Everything is good. You can turn on hotspot here.

        //}
      } catch (ApiException exception) {
        switch (exception.getStatusCode()) {
          case LocationSettingsStatusCodes.RESOLUTION_REQUIRED:
            // Location settings are not satisfied. But could be fixed by showing the
            // user a dialog.
            try {
              // Cast to a resolvable exception.
              ResolvableApiException resolvable = (ResolvableApiException) exception;
              // Show the dialog by calling startResolutionForResult(),
              // and check the result in onActivityResult().
              resolvable.startResolutionForResult(
                  MainActivity.this,
                  101);
            } catch (IntentSender.SendIntentException e) {
              // Ignore the error.
            } catch (ClassCastException e) {
              // Ignore, should be an impossible error.
            }
            break;
          case LocationSettingsStatusCodes.SETTINGS_CHANGE_UNAVAILABLE:
            // Location settings are not satisfied. However, we have no way to fix the
            // settings so we won't show the dialog.
            break;
        }
      }
    });
  }

Add this case to the onActivityResult method.

      case 101:
        final LocationSettingsStates states = LocationSettingsStates.fromIntent(data);
        switch (resultCode) {
          case Activity.RESULT_OK:
            // All required changes were successfully made
            Log.v("case 101", states.isLocationPresent() + "");

            //Everything is good. You can turn on hotspot here.

            break;
          case Activity.RESULT_CANCELED:
            // The user was asked to change settings, but chose not to
            Log.v("case 101", "Canceled");
            break;
          default:
            break;
        }
        break;

I recently created a demo app called Spotserve. That turns on wifi hotspot for all devices with API>=15 and hosts a demo server on that hotspot. You can check that for more details. Hope this helps!

来源：https://stackoverflow.com/questions/56082255/calling-wifimanager-startlocalonlyhotspot-throws-securityexception-even-after