5

i am trying to implement an WakeLock in my Android App. I have the following code in my onCreat():

pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
myWakeLock = pm.newWakeLock(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON,"WakeLock for Tuner");

The second line leading to a crash. It throws a Fatal Exception. As far as I can see Android says that the first Argument is no valid wake lock level. But on the developer Site it is recommended to use FLAG_KEEP_SCREEN_ON so i am a litte bit confused (http://developer.android.com/reference/android/os/PowerManager.html#newWakeLock%28int,%20java.lang.String%29)

Do I have to use the deprecated PowerManager.FULL_WAKE_LOCK ?

The following Code, as suggested in the Question How to get an Android WakeLock to work? , isn't the right way in my opinion.

getWindow().addFlags(LayoutParams.FLAG_KEEP_SCREEN_ON);

I don't need a Wakeup for the hole App. The App is a tuner for instruments and should only stay awake when the tuner is running. The plan ist to call myWakeLock.acquire() in the startTuner() Method and analogical myWakeLock.release() in the stopTuner() Method. I can't the how to realise that with the suggested way.

Here is the full Exception Message:

04-13 19:21:14.815: E/AndroidRuntime(9452): FATAL EXCEPTION: main
04-13 19:21:14.815: E/AndroidRuntime(9452): java.lang.RuntimeException: Unable to start activity ComponentInfo{de.benediktbock.ffttest/de.benediktbock.ffttest.MainActivity}: java.lang.IllegalArgumentException: Must specify a valid wake lock level.
04-13 19:21:14.815: E/AndroidRuntime(9452):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2249)
04-13 19:21:14.815: E/AndroidRuntime(9452):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2299)
04-13 19:21:14.815: E/AndroidRuntime(9452):     at android.app.ActivityThread.access$700(ActivityThread.java:154)
04-13 19:21:14.815: E/AndroidRuntime(9452):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1284)
04-13 19:21:14.815: E/AndroidRuntime(9452):     at android.os.Handler.dispatchMessage(Handler.java:99)
04-13 19:21:14.815: E/AndroidRuntime(9452):     at android.os.Looper.loop(Looper.java:137)
04-13 19:21:14.815: E/AndroidRuntime(9452):     at android.app.ActivityThread.main(ActivityThread.java:5306)
04-13 19:21:14.815: E/AndroidRuntime(9452):     at java.lang.reflect.Method.invokeNative(Native Method)
04-13 19:21:14.815: E/AndroidRuntime(9452):     at java.lang.reflect.Method.invoke(Method.java:511)
04-13 19:21:14.815: E/AndroidRuntime(9452):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1102)
04-13 19:21:14.815: E/AndroidRuntime(9452):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:869)
04-13 19:21:14.815: E/AndroidRuntime(9452):     at dalvik.system.NativeStart.main(Native Method)
04-13 19:21:14.815: E/AndroidRuntime(9452): Caused by: java.lang.IllegalArgumentException: Must specify a valid wake lock level.
04-13 19:21:14.815: E/AndroidRuntime(9452):     at android.os.PowerManager.validateWakeLockParameters(PowerManager.java:488)
04-13 19:21:14.815: E/AndroidRuntime(9452):     at android.os.PowerManager.newWakeLock(PowerManager.java:474)
04-13 19:21:14.815: E/AndroidRuntime(9452):     at de.benediktbock.ffttest.MainActivity.onCreate(MainActivity.java:62)
04-13 19:21:14.815: E/AndroidRuntime(9452):     at android.app.Activity.performCreate(Activity.java:5255)
04-13 19:21:14.815: E/AndroidRuntime(9452):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1097)
04-13 19:21:14.815: E/AndroidRuntime(9452):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2213)
04-13 19:21:14.815: E/AndroidRuntime(9452):     ... 11 more
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2 回答 2

9

但在开发者网站上建议使用 FLAG_KEEP_SCREEN_ON

这指的是 using 的替代方法WakeLock，如果您的目标只是在您的某些 UI 处于前台时保持屏幕打开。

我是否必须使用已弃用的 PowerManager.FULL_WAKE_LOCK ？

那将取决于您要做什么。您必须在 in 上使用这些常量PowerManager之一newWakeLock()。

该应用程序是乐器的调音器，只有在调音器运行时才应保持清醒。计划是在 startTuner() 方法中调用 myWakeLock.acquire() 并在 stopTuner() 方法中类比 myWakeLock.release()。我无法通过建议的方式来实现这一点。

当您想保持屏幕唤醒时，请在调谐器 UI 中调用setKeepScreenOn(true)一些。当您希望恢复正常的屏幕行为时，请在调谐器 UI 中View调用setKeepScreenOn(false)一些。View在这些调用之间，只要您的调谐器 UI 处于前台，屏幕就不会关闭。作为奖励，您不需要WAKE_LOCK许可。

于 2014-04-13T17:40:29.177 回答
3 
int PROXIMITY_WAKE_LOCK = 32;
PowerManager mgr=(PowerManager) getSystemService(Context.POWER_SERVICE);
proximityWakeLock = mgr.newWakeLock(PROXIMITY_WAKE_LOCK, "Beam");
于 2014-04-13T17:32:57.107 回答