Desbloquear el teléfono Android programáticamente?

Quiero escribir el código sobre cómo desbloquear el teléfono Android mediante programación.

Quiero bloquear o desbloquear el teléfono cuando el usuario toque el sensor de proximidad.

public class MyActivity extends Activity{ private static final String ACTION = "android.intent.action.ACTION_SCREEN_OFF"; BroadcastReceiver myReceiver; Context context; @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); context = this; final IntentFilter theFilter = new IntentFilter(); theFilter.addAction(ACTION); context.registerReceiver(myReceiver, theFilter); System.out.println("inside increate"); myReceiver = new BroadcastReceiver(){ @Override public void onReceive(Context context, Intent intent) { // TODO Auto-generated method stub System.out.println("phone locked*****"); } }; }} 

 @Override protected void onResume() { // TODO Auto-generated method stub super.onResume(); IntentFilter filter = new IntentFilter(Intent.ACTION_SCREEN_OFF); registerReceiver(mIntentReceiver, filter); System.out.println("BROADcast receiver registered****"); } private BroadcastReceiver mIntentReceiver = new BroadcastReceiver(){ @Override public void onReceive(Context context, Intent intent) { // TODO Auto-generated method stub System.out.println("phone locked"); } 

 Window window = getWindow(); window.addFlags(WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD | WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED | WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON | WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);