android - 在删除联系人或短信时在没有 Activity 的情况下在后台运行应用程序提醒用户

Question

我想让我的应用程序在后台运行并监听联系人，短信删除事件。为此，我在我的应用程序中创建了一项服务，但我不知道如何在没有 Activity 的情况下开始我的代码是这样的

public class DeleteService extends Service {

ContentResolver cr;

 MyContentObserver observer=new MyContentObserver();
@Override
public IBinder onBind(Intent arg0) {
    // TODO Auto-generated method stub
    return mBinder;
}
@Override
public void onCreate() {

     cpath=ContactsContract.Contacts.CONTENT_URI;

                // some action
        }

@Override

public void onDestroy() {

}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
// TODO Launch a background thread to do processing.
    super.onStartCommand(intent, flags, startId);
    cpath=ContactsContract.Contacts.CONTENT_URI;
    cr=getContentResolver();
    cur=cr.query(cpath, null, null, null, null);


    this.getApplicationContext().getContentResolver().registerContentObserver(cpath, true, observer);
    return Service.START_STICKY;

    }
 private class MyContentObserver extends ContentObserver {

        public MyContentObserver() {
            super(null);
        }

        @Override
        public void onChange(boolean selfChange) {
            super.onChange(selfChange);
            nfm=(NotificationManager)getSystemService(Context.NOTIFICATION_SERVICE);
            int NOTIFICATION_ID = 1;
       Intent intent1 = new Intent();
       PendingIntent pi = PendingIntent.getActivity(DeleteService.this, 1, intent1, 0);
       nf=new Notification(R.drawable.ic_launcher,"Contact Database changed",System.currentTimeMillis());
       nf.setLatestEventInfo(getApplicationContext(), "Delete Event", "contact name", pi);
       nf.flags = nf.flags |
             Notification.FLAG_ONGOING_EVENT;
    }
        @Override
        public boolean deliverSelfNotifications()
        { 
             super.deliverSelfNotifications();
            return true;

        }
}
 public class LocalBinder extends Binder {
        DeleteService getService() {
            return DeleteService.this;
        }

}
}

Answer 1

为服务中的应用程序注册ACTION_SCREEN_ON 或ACTION_USER_PRESENT 广播接收器，并在屏幕打开或用户出现时启动服务。您可以注册 ACTION_SCREEN_OFF 广播接收器以在手机屏幕关闭时停止服务，以避免您的应用耗尽电池电量。如:

在 manifest.xml 中:

<receiver android:name="com.my.AppStart">  
    <intent-filter>  
        <action android:name="android.intent.action.SCREEN_ON" />  
        <action android:name="android.intent.action.SCREEN_OFF" /> 
        <action android:name="android.intent.action.USER_PRESENT" /> 
    </intent-filter>  
</receiver>

广播接收器:

public class AppStart extends BroadcastReceiver {
public static final String present = "android.intent.action.USER_PRESENT";
public static final String screenon = "android.intent.action.SCREEN_ON";
public static final String screenoff = "android.intent.action.SCREEN_OFF";
    @Override
    public void onReceive(Context context, Intent intent) {

    if (intent.getAction().equals(present) || intent.getAction().equals(screenon) )
    {
        Intent i=new Intent(context,DeleteService.class);
        context.startService(i);
    }
    if (intent.getAction().equals(screenoff))
    {
       //STOP YOUR SERVICE HERE
    }

   }
}