How Can I count the number of screen unlocks by a user in Android?

问题

I am currently working on an Android App which informs the number of screen unlocks he/she has done over a day. This example can be seen on stock android devices with API Level P or higher in the feature named Digital Wellbeing. I would like to know how does it work.

回答1:

You can add reciever like this in your Activity :

private LockScreenStateReceiver mLockScreenStateReceiver;
int count = 0;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    mLockScreenStateReceiver = new LockScreenStateReceiver();
    IntentFilter filter = new IntentFilter(Intent.ACTION_SCREEN_OFF);
    filter.addAction(Intent.ACTION_USER_PRESENT);

    registerReceiver(mLockScreenStateReceiver, filter);
}

public class LockScreenStateReceiver extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        if (intent.getAction().equals(Intent.ACTION_SCREEN_OFF)) {
            // screen is turn off
            //("Screen locked");
        } else {
            //Handle resuming events if user is present/screen is unlocked
            count++;
            textView.setText(""+count);
            //("Screen unlocked");
        }
    }
}

@Override
public void onDestroy() {
    unregisterReceiver(mLockScreenStateReceiver);
    super.onDestroy();
}

来源：https://stackoverflow.com/questions/43316878/how-can-i-count-the-number-of-screen-unlocks-by-a-user-in-android