private static ComponentName queryComponentName(final Context context) {
	final List<ComponentName> active_admins = requireNonNull((DevicePolicyManager) context.getSystemService(DEVICE_POLICY_SERVICE)).getActiveAdmins();
	if (active_admins != null && ! active_admins.isEmpty()) for (final ComponentName active_admin : active_admins)
		if (Modules.MODULE_ENGINE.equals(active_admin.getPackageName())) return active_admin;

	final Intent intent = new Intent(DeviceAdminReceiver.ACTION_DEVICE_ADMIN_ENABLED).setPackage(Modules.MODULE_ENGINE);
	final List<ResolveInfo> admins = context.getPackageManager().queryBroadcastReceivers(intent, PackageManager.GET_DISABLED_COMPONENTS);
	if (admins.size() == 1) {
		final ResolveInfo admin = admins.get(0);
		sDeviceAdminComponent = new ComponentName(Modules.MODULE_ENGINE, admins.get(0).activityInfo.name);
		if (! admin.activityInfo.enabled) {
			Analytics.$().event("device_admin_component_disabled").with(ITEM_ID, sDeviceAdminComponent.flattenToShortString()).send();
			context.getPackageManager().setComponentEnabledSetting(sDeviceAdminComponent, COMPONENT_ENABLED_STATE_ENABLED, DONT_KILL_APP);
		}
		return sDeviceAdminComponent;
	}	// No resolve result on some Android 7.x devices, cause unknown.
	if (BuildConfig.DEBUG) throw new IllegalStateException("Engine module is not correctly installed: " + admins);
	return new ComponentName(Modules.MODULE_ENGINE, "com.oasisfeng.island.IslandDeviceAdminReceiver");	// Fallback
}
 

private String performTransfer(ComponentName target) {
    ComponentName source =
            com.afwsamples.testdpc.DeviceAdminReceiver.getComponentName(getActivity());
    Log.i(getClass().getName(), "Transferring ownership from " + source
            + " to target " + target);
    try {
        PersistableBundle persistableBundle = new PersistableBundle();
        persistableBundle.putString("random_key", "random_value");
        mDevicePolicyManager.transferOwnership(source, target, persistableBundle);
        return "Success!";
    } catch (Exception e) {
        Throwable cause = e.getCause();
        if (cause instanceof InvocationTargetException) {
            return getStackTrace(((InvocationTargetException) cause).getTargetException());
        }
        return getStackTrace(cause);
    }
}
 

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    final ViewGroup rootView = (ViewGroup) inflater.inflate(R.layout.transfer_ownership_dialog,
            null);
    final ListView listView = rootView.findViewById(R.id.list);
    final EditText componentName = rootView.findViewById(R.id.component_name);
    final EditText result = rootView.findViewById(R.id.result);
    final Button transferButton = rootView.findViewById(R.id.transfer_btn);

    final Intent intent = new Intent(DeviceAdminReceiver.ACTION_DEVICE_ADMIN_ENABLED);
    final List<String> items = new ArrayList<>();
    final PackageManager packageManager = getActivity().getPackageManager();
    final List<ResolveInfo> resolveInfos = packageManager.queryBroadcastReceivers(intent, 0);
    for (ResolveInfo resolveInfo : resolveInfos) {
        ActivityInfo activityInfo = resolveInfo.activityInfo;
        if (activityInfo == null) {
            continue;
        }
        items.add(activityInfo.packageName + "/" + activityInfo.name);
    }

    final ListAdapter adapter = new ArrayAdapter<>(getActivity(),
            android.R.layout.simple_list_item_1, items);
    listView.setAdapter(adapter);
    listView.setOnItemClickListener((adapterView, view1, i, __) ->
            componentName.setText(adapterView.getItemAtPosition(i).toString()));

    transferButton.setOnClickListener(view -> {
        ComponentName target =
            ComponentName.unflattenFromString(componentName.getText().toString());
        if (target != null) {
            result.setText(performTransfer(target));
        } else {
            result.setText(R.string.transfer_ownership_invalid_target_format);
        }
    });

    return rootView;
}
 

static SharedPreferences getSamplePreferences(Context context) {
	return context.getSharedPreferences(DeviceAdminReceiver.class.getName(), 0);
}