Android keeps the screen solid awake state

First step: Add Permissions First:

<uses-permission android:name= "Android.permission.WAKE_LOCK" ></uses-permission>

The second step: the code is implemented as follows:

public class Screenactivity extends Activity   {        PowerManager powermanager = null;        WakeLock WakeLock = null;        @Override        protected void onCreate (Bundle savedinstancestate) {            super.oncreate (savedinstancestate);            This.setcontentview (r.layout.main);            PowerManager = (PowerManager) This.getsystemservice (this. Power_service);            WakeLock = This.powerManager.newWakeLock (Powermanager.full_wake_lock, "My LOCK");       }       @Override       protected void Onresume () {           super.onresume ();           Wakelock.acquire ();       }       @Override       protected void OnPause () {           super.onpause ();           Wakelock.release ();       }   }

The last note: calling the Wakelock function in a different life cycle can make the system run normally (if the activity ends without calling wakelock.release, the screen will always be solid).