141

For my Android app I never want the phone to lock or the back light to turn off

Seth Hikari
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11 Answers11

242

Add one line of code after setContentView() in onCreate()

public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_flag);
        getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
}
Duc Tran
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130

Lots of answers already exist here! I am answering this question with additional and reliable solutions:

Using PowerManager.WakeLock is not so reliable a solution, as the app requires additional permissions.

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

Also, if it accidentally remains holding the wake lock, it can leave the screen on.

So, I recommend not using the PowerManager.WakeLock solution. Instead of this, use any of the following solutions:

First:

We can use getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON); in onCreate()

@Override
        protected void onCreate(Bundle icicle) {
            super.onCreate(icicle);    
            getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
        }

Second:

we can use keepScreenOn

1. implementation using setKeepScreenOn() in java code:

@Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        View v = getLayoutInflater().inflate(R.layout.driver_home, null);// or any View (incase generated programmatically ) 
        v.setKeepScreenOn(true);
        setContentView(v);
       }

Docs http://developer.android.com/reference/android/view/View.html#setKeepScreenOn(boolean)

2. Adding keepScreenOn to xml layout

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:keepScreenOn="true" >

Docs http://developer.android.com/reference/android/view/View.html#attr_android%3akeepScreenOn

Notes (some useful points):

  1. It doesn't matter that keepScreenOn should be used on a Main/Root/Parent View. It can be used with any child view and will work the same way it works in a parent view.
  2. The only thing that matters is that the view's visibility must be visible. Otherwise, it will not work!
senshin
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Tarsem Singh
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105

Use PowerManager.WakeLock class inorder to perform this. See the following code:

import android.os.PowerManager;

public class MyActivity extends Activity {

    protected PowerManager.WakeLock mWakeLock;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(final Bundle icicle) {
        setContentView(R.layout.main);

        /* This code together with the one in onDestroy() 
         * will make the screen be always on until this Activity gets destroyed. */
        final PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
        this.mWakeLock = pm.newWakeLock(PowerManager.SCREEN_DIM_WAKE_LOCK, "My Tag");
        this.mWakeLock.acquire();
    }

    @Override
    public void onDestroy() {
        this.mWakeLock.release();
        super.onDestroy();
    }
}

Use the follwing permission in manifest file :

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

Hope this will solve your problem...:)

Gourneau
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Dinesh Sharma
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    Shouldn't this be in `onResuem` and `onPause` so the app won't keep the screen on when user hits the home button? – Li_W Sep 23 '11 at 03:29
  • Does PowerManager pm have to be declared as final? – IgorGanapolsky Oct 31 '12 at 00:53
  • Not so good proposal for what @SethHikari asked.. Too much work, too much cpu power consumed.. – Ewoks Jun 19 '13 at 13:18
  • In case this helps anyone else, another answer with lower ratings (http://stackoverflow.com/a/14926037/498949) works just as well and doesn't rely on you releasing the wakelock. – Chris Rae Nov 06 '13 at 18:18
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    This method is deprecated, you can refer to the documentation here: http://developer.android.com/reference/android/os/PowerManager.html#SCREEN_DIM_WAKE_LOCK – Chris.Zou Nov 16 '13 at 16:37
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    Please remove this answer, which is obsolete. Thank you. – interlude Jan 12 '15 at 14:50
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    [**PLEASE DO NOT USE A WAKE LOCK**](http://stackoverflow.com/a/2134602/119527). – Jonathon Reinhart Aug 04 '15 at 02:06
  • I don't think the answer should be removed, just edited to state that it's deprecated and that it's best to simply use a `FLAG_KEEP_SCREEN_ON` flag. – Mauker Oct 26 '16 at 23:09
  • **It is deprecated**. You can just add `android:keepScreenOn="true"` on XML file or add `getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);` on onCreate Activity. [Android Developer](https://developer.android.com/training/scheduling/wakelock.html#screen) – Lucas Jan 17 '17 at 01:06
  • Do not delete this answer. There are a few cases where getWindow().addFlags(FLAG_KEEP_SCREEN_ON) does not work as intention. – Naetmul Apr 13 '17 at 04:02
  • @Naetmul Can you give us some example? – Federico Ponzi May 03 '17 at 18:34
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    @FedericoPonzi Case 1: When you need only SCREEN_DIM_WAKE_LOCK, not SCREEN_BRIGHT_WAKE_LOCK. Case 2: When you need screen wake lock while another developer's app is running in the foreground, where you cannot directly get the Window of that app. – Naetmul May 04 '17 at 06:13
  • @interlude why remove it? It's still useful for niche applications. – TheWanderer Aug 21 '18 at 23:15
57

Don't Use Wake Lock.

It requires permission and other stuff and may cause error if you forget to set it in right time.

The easiest way is to use the below code when you want to keep your screen on..

 getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);

One addition to the answer if you want to remove or terminate keep_Screen_on

getWindow().clearFlags(android.view.WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);

you can also see here..

And the best and easiest way .. Using android:keepScreenOn="true" in layout root of your activity does the same thing without extra code. But it will remain it in Keep_Scree_on State..

It can be vary on your demand See here

Pang
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Zar E Ahmer
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  • Works great. I also clear the flag in onStop so screen on state behaves as usual when outside my app. For some odd reason it seemed to work without doing that but seems to be the correct way to do it anyway so to be sure I'll leave it (perhaps it works differently on other phones than my Nexus 5). – riper Jan 06 '15 at 14:39
15
getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);

getWindow is a method defined for activities, and won't require you to find a View first.

Pratik Butani
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12

Adding android:keepScreenOn="true" in the XML of the activity(s) you want to keep the screen on is the best option. Add that line to the main layout of the activity(s).

Something like this

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:keepScreenOn="true">

...

</LinearLayout>
The Berga
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10

You can simply use setKeepScreenOn() from the View class.

Godsmith
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Gelldur
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10

There are multiple ways you can do it:

Solution 1:

class MainActivity extends AppCompactActivity {
    @Override
    protected void onCreate(Bundle icicle) {
        super.onCreate(icicle);    
        getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
    }
}

Solution 2:

In activity_main.xml file, simply add:

<android:KeepScreenOn="true"/>

My advice: please don't use WakeLock. If you use it, you have to define extra permission, and mostly this thing is useful in CPU's development environment.

Also, make sure to turn off the screen while closing the activity. You can do it in this way:

public void onDestry() {
    getWindow().clearFlags(android.view.WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
}
Patrick
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Hemanth Kumar
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4

No need to add permission and do tricks. Just use below text in your main layout.

  android:keepScreenOn="true"
SilverSky
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4

You need to use Power Manager to acquire a wake lock in your application.

Most probably you are interested in a FULL_WAKE_LOCK:

PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
PowerManager.WakeLock wl = pm.newWakeLock(PowerManager.FULL_WAKE_LOCK, "My Tag");
wl.acquire();
....
wl.release();
Marcin Gil
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  • he's talking about screen (can be solved with one flag), why did you suggest FULL_WAKE_LOCK? – user25 Mar 24 '18 at 22:59
1

At this point method

final PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
        this.mWakeLock = pm.newWakeLock(PowerManager.SCREEN_DIM_WAKE_LOCK, "My Tag");
        this.mWakeLock.acquire();

is deprecated.

You should use getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON); and getWindow().clearFlags(android.view.WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);

nikosid
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