MyService.java

package com.halzhang.android.examples.lockscreenexample;

import android.app.Service;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.IBinder;
import android.util.Log;

public class MyService extends Service {
    private static final String TAG = "MyService";

    public MyService() {
    }

    @Override
    public void onCreate() {
        super.onCreate();
        IntentFilter intentFilter = new IntentFilter();
        intentFilter.addAction(Intent.ACTION_SCREEN_ON);
        registerReceiver(mReceiver, intentFilter);
    }

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

    @Override
    public IBinder onBind(Intent intent) {
        // TODO: Return the communication channel to the service.
        throw new UnsupportedOperationException("Not yet implemented");
    }

    private BroadcastReceiver mReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();
            Log.w(TAG, "onReceive: " + action);
            if (Intent.ACTION_SCREEN_ON.equals(action)) {
                Intent lockScreenIntent = new Intent(context, LockScreenActivity.class);
                lockScreenIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                context.startActivity(lockScreenIntent);
            }
        }
    };
}