This class gives you control of the power state of the device.

Flag Value	Description
PowerManager.ACQUIRE_CAUSES_WAKEUP	Normal wake locks don't actually turn on the illumination. Instead, they cause the illumination to remain on once it turns on (e.g. from user activity). This flag will force the screen and/or keyboard to turn on immediately, when the WakeLock is acquired. A typical use would be for notifications which are important for the user to see immediately.
PowerManager.ON_AFTER_RELEASE	If this flag is set, the user activity timer will be reset when the WakeLock is released, causing the illumination to remain on a bit longer. This can be used to reduce flicker if you are cycling between wake lock conditions.

Device battery life will be significantly affected by the use of this API. Do not acquire NoType:android/os/PowerManager$WakeLock;Href=../../../reference/android/os/PowerManager.WakeLock.htmls unless you really need them, use the minimum levels possible, and be sure to release them as soon as possible.

You can obtain an instance of this class by calling Android.Content.Context.GetSystemService(string).

The primary API you'll use is PowerManager.NewWakeLock(WakeLockFlags, System.String). This will create a NoType:android/os/PowerManager$WakeLock;Href=../../../reference/android/os/PowerManager.WakeLock.html object. You can then use methods on the wake lock object to control the power state of the device.

In practice it's quite simple:

PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
 PowerManager.WakeLock wl = pm.newWakeLock(PowerManager.SCREEN_DIM_WAKE_LOCK, "My Tag");
 wl.acquire();
   ..screen will stay on during this section..
 wl.release();
 

The following wake lock levels are defined, with varying effects on system power. These levels are mutually exclusive - you may only specify one of them.

Flag Value	CPU	Screen	Keyboard
PowerManager.PARTIAL_WAKE_LOCK	On*	Off	Off
PowerManager.SCREEN_DIM_WAKE_LOCK	On	Dim	Off
PowerManager.SCREEN_BRIGHT_WAKE_LOCK	On	Bright	Off
PowerManager.FULL_WAKE_LOCK	On	Bright	Bright

*If you hold a partial wake lock, the CPU will continue to run, regardless of any display timeouts or the state of the screen and even after the user presses the power button. In all other wake locks, the CPU will run, but the user can still put the device to sleep using the power button.

In addition, you can add two more flags, which affect behavior of the screen only. These flags have no effect when combined with a PowerManager.PARTIAL_WAKE_LOCK.

Any application using a WakeLock must request the android.permission.WAKE_LOCK permission in an <uses-permission> element of the application's manifest.

[Android Documentation]