android：在接近脸部时关闭屏幕

Question

我的应用允许用户访问他们的企业语音邮件。通常，当用户将设备放在耳边时，通过拨打电话屏幕会关闭，这样他们就不会不小心按下脸部按钮。我想让我的应用在用户收听他们的语音邮件时也做同样的事情。

任何人都知道如何做到这一点？

Answer 1

您所看到的是使用接近传感器。对于有设备的设备，您可以通过SensorManager进行访问。

Answer 2

如果您可以查看开源代码而不会导致您的问题，请检查Android Phone Application的来源。具体为src/com/android/phone/PhoneApp.java和src/com/android/phone/InCallScreen.java。

从SRC/COM /安卓/电话/ PhoneApp.java：

//Around line 519 
// Wake lock used to control proximity sensor behavior. 
if ((pm.getSupportedWakeLockFlags() 
      & PowerManager.PROXIMITY_SCREEN_OFF_WAKE_LOCK) != 0x0) { 
    mProximityWakeLock = pm.newWakeLock(
     PowerManager.PROXIMITY_SCREEN_OFF_WAKE_LOCK, 
     LOG_TAG); 
} 

.... 
// Around line 1334 
if (((state == Phone.State.OFFHOOK) || mBeginningCall)&& !screenOnImmediately) { 
    // Phone is in use! Arrange for the screen to turn off 
    // automatically when the sensor detects a close object. 
    if (!mProximityWakeLock.isHeld()) { 
     if (DBG) Log.d(LOG_TAG, "updateProximitySensorMode: acquiring..."); 
     mProximityWakeLock.acquire(); 
    } else { 
     if (VDBG) Log.d(LOG_TAG, "updateProximitySensorMode: lock already held."); 
    } 
} else { 
    // Phone is either idle, or ringing. We don't want any 
    // special proximity sensor behavior in either case. 
    if (mProximityWakeLock.isHeld()) { 
    if (DBG) Log.d(LOG_TAG, "updateProximitySensorMode: releasing..."); 
    // Wait until user has moved the phone away from his head if we are 
    // releasing due to the phone call ending. 
    // Qtherwise, turn screen on immediately 
    int flags = 
     (screenOnImmediately ? 0 : PowerManager.WAIT_FOR_PROXIMITY_NEGATIVE); 
    mProximityWakeLock.release(flags); 
    } 
} 

此外，如果你看一下在电源管理器类的代码，PROXIMITY_SCREEN_OFF_WAKE_LOCK是记录（但隐藏）和应该做你想要什么（然而，我不确定这是适用于哪个API级别），但由于某种原因，不在表格中。

/** 
* Wake lock that turns the screen off when the proximity sensor activates. 
* Since not all devices have proximity sensors, use 
* {@link #getSupportedWakeLockFlags() getSupportedWakeLockFlags()} to determine if 
* this wake lock mode is supported. 
* 
* {@hide} 
*/ 
public static final int PROXIMITY_SCREEN_OFF_WAKE_LOCK = WAKE_BIT_PROXIMITY_SCREEN_OFF; 

如果您不害怕使用潜在的未记录功能，它应该按照您的需要进行操作。

Answer 3

也许你不需要它了，但对于那些有兴趣在代码中的人，你可以看看我的SpeakerProximity项目在http://code.google.com/p/speakerproximity/

Answer 4

为API级别21（棒棒堂），你可以得到接近唤醒锁这就像这样：

if(powerManager.isWakeLockLevelSupported(PowerManager.PROXIMITY_SCREEN_OFF_WAKE_LOCK)) { 
     PowerManager.WakeLock wakeLock = powerManager.newWakeLock(PowerManager.PROXIMITY_SCREEN_OFF_WAKE_LOCK, TAG); 
     wakeLock.setReferenceCounted(false); 
     return wakeLock; 
    } else { 
     return null; 
    } 
} 

那么它是由你来获得和释放锁。

PS：PowerManager#getSupportedWakeLockFlags已被隐藏，但现在存在nomore。相反，他们发明了isWakeLockLevelSupported。