android - 发生特定事件时如何在 Android 上打开屏幕？

Question

我正在尝试创建一个闹钟应用程序，它应该在给定的时间段后响起。它在屏幕打开时工作；我打开应用程序，闹钟在 5 秒后响起。这正是我想要的。

现在，我希望我的应用在屏幕关闭时以相同的方式运行。所以，如果我打开我的应用程序然后关闭屏幕，我希望应用程序在 5 秒后打开屏幕，然后响铃。

我尝试了 SCREEN_BRIGHT_WAKE_LOCK(确实设置了所需的权限)但它没有用。闹钟响了半秒钟，然后就关掉了。屏幕根本没有亮起。此外，SCREEN_BRIGHT_WAKE_LOCK 已被弃用，文档建议使用 FLAG_KEEP_SCREEN_ON，这仅在屏幕已经打开并且我们希望保持这种状态时才有用。不要从关闭状态打开它。

我需要做什么来解决上述问题？使用服务？此外，屏幕被数字锁锁定。

这是我的代码，它仅在屏幕打开时有效:

public class AlarmReceiverActivity extends Activity {



       private MediaPlayer mMediaPlayer;

        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            this.requestWindowFeature(Window.FEATURE_NO_TITLE);
            this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
                    WindowManager.LayoutParams.FLAG_FULLSCREEN);
            setContentView(R.layout.activity_alarm_receiver);

            Button stopAlarm = (Button) findViewById(R.id.stopAlarm);
            stopAlarm.setOnTouchListener(new View.OnTouchListener() {
                public boolean onTouch(View arg0, MotionEvent arg1) {
                    mMediaPlayer.stop();
                    mMediaPlayer.release();
                    finish();
                    return false;
                }
            });

            playSound(this, getAlarmUri());
        }

        private void playSound(Context context, Uri alert) {
            mMediaPlayer = new MediaPlayer();
            try {
                mMediaPlayer.setDataSource(context, alert);
                final AudioManager audioManager = (AudioManager) context
                        .getSystemService(Context.AUDIO_SERVICE);
                if (audioManager.getStreamVolume(AudioManager.STREAM_ALARM) != 0) {
                    mMediaPlayer.setAudioStreamType(AudioManager.STREAM_ALARM);

                    try {
                        mMediaPlayer.prepare();
                        mMediaPlayer.start();
                    } catch (IOException e) {
                        System.out.println("Oops");
                    }

                }
            } catch (IOException e1) {
                System.out.println("OOPS");
            }
        }

        //Get an alarm sound. Try for an alarm. If none set, try notification,
        //Otherwise, ringtone.
        private Uri getAlarmUri() {
            Uri alert = RingtoneManager
                    .getDefaultUri(RingtoneManager.TYPE_ALARM);
            if (alert == null) {
                alert = RingtoneManager
                        .getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
                if (alert == null) {
                    alert = RingtoneManager
                            .getDefaultUri(RingtoneManager.TYPE_RINGTONE);
                }
            }
            return alert;
        }
    }

Answer 1

我最近正在处理这个问题。这对我有用:

public class YourActivity extends Activity {

...

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main_view);
    getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON |
                         WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD |
                         WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED |
                         WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON);

...

}

有用的链接:

Android Activity Not Showing When Screen is Woken Up and Lock Screen Not Disabling

http://weimenglee.blogspot.co.il/2013/04/android-tip-waking-up-screen-and.html

Android Galaxy S4 -- Activity that is visible over lock screen

也不要在 Activity 中使用对话框主题!!!