Android - 如何接收广播意图ACTION_SCREEN_ON/OFF？

Question

    <application>
         <receiver android:name=".MyBroadcastReceiver" android:enabled="true">
                <intent-filter>
                      <action android:name="android.intent.action.ACTION_SCREEN_ON"></action>
                      <action android:name="android.intent.action.ACTION_SCREEN_OFF"></action>
                </intent-filter>
         </receiver>
...
    </application>

MyBroadcastReceiver设置只是为了向日志吐出foo.什么也没做.有什么建议吗？我是否需要分配任何权限来捕获意图？

Answer 1

我相信这些行为只能由在Java代码(via registerReceiver())中注册的接收者接收,而不是通过清单中注册的接收者接收.

Answer 2

或者,您可以使用电源管理器来检测屏幕锁定.

@Override
protected void onPause()
{
    super.onPause();

    // If the screen is off then the device has been locked
    PowerManager powerManager = (PowerManager) getSystemService(POWER_SERVICE);
    boolean isScreenOn;
    if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT_WATCH) {
        isScreenOn = powerManager.isInteractive();
    } else {
        isScreenOn = powerManager.isScreenOn();
    }

    if (!isScreenOn) {

        // The screen has been locked 
        // do stuff...
    }
}

Answer 3

"android.intent.action.HEADSET_PLUG"
"android.intent.action.ACTION_SCREEN_ON"
"android.intent.action.ACTION_SCREEN_OFF"

其中三个,他们无法使用Manifest注册.Android核心向他们添加了"Intent.FLAG_RECEIVER_REGISTERED_ONLY"(也许..我只检查了代码"HEADSET_PLUG").

所以,我们应该使用"动态寄存器".如下......

private BroadcastReceiver mPowerKeyReceiver = null;

private void registBroadcastReceiver() {
    final IntentFilter theFilter = new IntentFilter();
    /** System Defined Broadcast */
    theFilter.addAction(Intent.ACTION_SCREEN_ON);
    theFilter.addAction(Intent.ACTION_SCREEN_OFF);

    mPowerKeyReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            String strAction = intent.getAction();

            if (strAction.equals(Intent.ACTION_SCREEN_OFF) || strAction.equals(Intent.ACTION_SCREEN_ON)) {
                // > Your playground~!
            }
        }
    };

    getApplicationContext().registerReceiver(mPowerKeyReceiver, theFilter);
}

private void unregisterReceiver() {
    int apiLevel = Build.VERSION.SDK_INT;

    if (apiLevel >= 7) {
        try {
            getApplicationContext().unregisterReceiver(mPowerKeyReceiver);
        }
        catch (IllegalArgumentException e) {
            mPowerKeyReceiver = null;
        }
    }
    else {
        getApplicationContext().unregisterReceiver(mPowerKeyReceiver);
        mPowerKeyReceiver = null;
    }
}

Answer 4

我实现这个的方法是在onCreate()的主要活动中注册接收器,只需事先在某处定义接收器:

    lockScreenReceiver = new LockScreenReceiver();
    IntentFilter lockFilter = new IntentFilter();
    lockFilter.addAction(Intent.ACTION_SCREEN_ON);
    lockFilter.addAction(Intent.ACTION_SCREEN_OFF);
    lockFilter.addAction(Intent.ACTION_USER_PRESENT);
    registerReceiver(lockScreenReceiver, lockFilter);

然后onDestroy():

    unregisterReceiver(lockScreenReceiver);

在接收器中,您必须捕获以下情况:

public class LockScreenReceiver extends BroadcastReceiver
{
    @Override
    public void onReceive(Context context, Intent intent)
    {
        if (intent != null && intent.getAction() != null)
        {
            if (intent.getAction().equals(Intent.ACTION_SCREEN_ON))
            {
                // Screen is on but not unlocked (if any locking mechanism present)
            }
            else if (intent.getAction().equals(Intent.ACTION_SCREEN_OFF))
            {
                // Screen is locked
            }
            else if (intent.getAction().equals(Intent.ACTION_USER_PRESENT))
            {
                // Screen is unlocked
            }
        }
    }
}