Could not re-enable the KeyGaurd once disabled it

问题

I have write below code to toggle the KeyGaurd of my android phone using a toggle button. but I am facing an strange behavior.

• it disables the keygaurd successfully but. not re-enabling.

   btnToggleLock.setOnClickListener(new OnClickListener() {
      @Override
      public void onClick(View v) {
  
          if (btnToggleLock.isChecked()) {
  
              toast.cancel();
              toast.setText("Unlocked");
              toast.show();
  
              Log.i("Unlocked", "If");
  
              KeyguardManager myKeyGuard = (KeyguardManager) getSystemService(Context.KEYGUARD_SERVICE);
  
              KeyguardLock myLock = myKeyGuard
                      .newKeyguardLock(KEYGUARD_SERVICE);
              myLock.disableKeyguard();
  
  
          } else {
  
              toast.cancel();
              toast.setText("Locked");
              toast.show();
  
              KeyguardManager myKeyGuard = (KeyguardManager) getSystemService(Context.KEYGUARD_SERVICE);
              KeyguardLock myLock = myKeyGuard
                      .newKeyguardLock(KEYGUARD_SERVICE);
              myLock.reenableKeyguard();
  
              Log.i("Locked", "else");
  
          }
  
      }
  });
  

• it disables the keygaurd successfully but. not re-enabling.

• I tested it the control is traversing both if and as well as else

also I m using android 2.2.1 motoralla milestone.

回答1:

The issue here is that you are creating a new Lock (KeyGuardLock) every time the "if" statement executes. You can disable a lock the first time when you create it but you must "reenable" the lock which you disabled in the first place, you cannot create a new one.

The solution is to make the lock outside of the onClickListener. i.e. Take the following code out of the "if" statement and declare it before setting the onClickListener:-

KeyguardManager myKeyGuard = (KeyguardManager) getSystemService(Context.KEYGUARD_SERVICE);
            KeyguardLock myLock = myKeyGuard
                    .newKeyguardLock(KEYGUARD_SERVICE);

来源：https://stackoverflow.com/questions/15338400/could-not-re-enable-the-keygaurd-once-disabled-it