android：在接近臉部時關閉屏幕

Question

我的應用允許用戶訪問他們的企業語音郵件。通常，當用戶將設備放在耳邊時，通過撥打電話屏幕會關閉，這樣他們就不會不小心按下臉部按鈕。我想讓我的應用在用戶收聽他們的語音郵件時也做同樣的事情。

任何人都知道如何做到這一點？

Answer 1

您所看到的是使用接近傳感器。對於有設備的設備，您可以通過SensorManager進行訪問。

Answer 2

如果您可以查看開源代碼而不會導致您的問題，請檢查Android Phone Application的來源。具體爲src/com/android/phone/PhoneApp.java和src/com/android/phone/InCallScreen.java。

從SRC/COM /安卓/電話/ 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，如果你看一下在電源管理器類的代碼，PROXIMITY_SCREEN_OFF_WAKE_LOCK是記錄（但隱藏）和應該做你想要什麼（然而，我不確定這是適用於哪個API級別），但由於某種原因，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; 

如果您不害怕使用潛在的未記錄功能，它應該按照您的需要進行操作。

Answer 3

也許你不需要它了，但對於那些有興趣在代碼中的人，你可以看看我的SpeakerProximity項目在http://code.google.com/p/speakerproximity/

Answer 4

爲API級別21（棒棒堂），你可以得到接近喚醒鎖這就像這樣：

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; 
    } 
} 

那麼它是由你來獲得和釋放鎖。

PS：PowerManager#getSupportedWakeLockFlags已被隱藏，但現在存在nomore。相反，他們發明了isWakeLockLevelSupported。