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How to turn Android device screen on and off programmatically?
This example demonstrate about How to turn Android device screen on and off programmatically.
Step 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.
Step 2 − Add the following code to res/layout/activity_main.xml
<? xml version= "1.0" encoding= "utf-8" ?> <RelativeLayout 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 :layout_margin= "16dp" tools :context= ".MainActivity" > <LinearLayout android :layout_width= "match_parent" android :layout_height= "wrap_content" android :layout_centerInParent= "true" android :orientation= "horizontal" > <Button android :id= "@+id/btnEnable" android :layout_width= "0dp" android :layout_height= "wrap_content" android :layout_weight= "1" android :onClick= "enablePhone" android :text= "Enable" /> <Button android :id= "@+id/btnLock" android :layout_width= "0dp" android :layout_height= "wrap_content" android :layout_weight= "1" android :onClick= "lockPhone" android :text= "Lock" /> </LinearLayout> </RelativeLayout>
Step 3 − Add the following code to res/xml/policies.xml
<? xml version= "1.0" encoding= "utf-8" ?> <device-admin xmlns: android = "http://schemas.android.com/apk/res/android" > <uses-policies> <force-lock /> </uses-policies> </device-admin>
Step 4 − Add the following code to src/DeviceAdmin
package app.tutorialspoint.com.sample ;
import android.app.admin.DeviceAdminReceiver ;
import android.content.Context ;
import android.content.Intent ;
import android.widget.Toast ;
public class DeviceAdmin extends DeviceAdminReceiver {
@Override
public void onEnabled (Context context , Intent intent) {
super .onEnabled(context , intent) ;
Toast. makeText (context , "Enabled" , Toast. LENGTH_SHORT ).show() ;
}
@Override
public void onDisabled (Context context , Intent intent) {
super .onDisabled(context , intent) ;
Toast. makeText (context , "Disabled" , Toast. LENGTH_SHORT ).show() ;
}
}Step 5 − Add the following code to src/MainActivity
package app.tutorialspoint.com.sample ;
import android.app.Activity ;
import android.app.admin.DevicePolicyManager ;
import android.content.ComponentName ;
import android.content.Context ;
import android.content.Intent ;
import android.support.annotation. Nullable ;
import android.support.v7.app.AppCompatActivity ;
import android.os.Bundle ;
import android.view.View ;
import android.widget.Button ;
import android.widget.Toast ;
public class MainActivity extends AppCompatActivity {
static final int RESULT_ENABLE = 1 ;
DevicePolicyManager deviceManger ;
ComponentName compName ;
Button btnEnable , btnLock ;
@Override
protected void onCreate (Bundle savedInstanceState) {
super .onCreate(savedInstanceState) ;
setContentView(R.layout. activity_main ) ;
btnEnable = findViewById(R.id. btnEnable ) ;
btnLock = findViewById(R.id. btnLock ) ;
deviceManger = (DevicePolicyManager)
getSystemService(Context. DEVICE_POLICY_SERVICE ) ;
compName = new ComponentName( this, DeviceAdmin. class ) ;
boolean active = deviceManger .isAdminActive( compName ) ;
if (active) {
btnEnable .setText( "Disable" ) ;
btnLock .setVisibility(View. VISIBLE ) ;
} else {
btnEnable .setText( "Enable" ) ;
btnLock .setVisibility(View. GONE ) ;
}
}
public void enablePhone (View view) {
boolean active = deviceManger .isAdminActive( compName ) ;
if (active) {
deviceManger .removeActiveAdmin( compName ) ;
btnEnable .setText( "Enable" ) ;
btnLock .setVisibility(View. GONE ) ;
} else {
Intent intent = new Intent(DevicePolicyManager. ACTION_ADD_DEVICE_ADMIN ) ;
intent.putExtra(DevicePolicyManager. EXTRA_DEVICE_ADMIN , compName ) ;
intent.putExtra(DevicePolicyManager. EXTRA_ADD_EXPLANATION , "You should enable the app!" ) ;
startActivityForResult(intent , RESULT_ENABLE ) ;
}
}
public void lockPhone (View view) {
deviceManger .lockNow() ;
}
@Override
protected void onActivityResult ( int requestCode , int resultCode , @Nullable Intent
data) {
super .onActivityResult(requestCode , resultCode , data) ;
switch (requestCode) {
case RESULT_ENABLE :
if (resultCode == Activity. RESULT_OK ) {
btnEnable .setText( "Disable" ) ;
btnLock .setVisibility(View. VISIBLE ) ;
} else {
Toast. makeText (getApplicationContext() , "Failed!" ,
Toast. LENGTH_SHORT ).show() ;
}
return;
}
}
}Step 6 − Add the following code to androidManifest.xml
<? xml version= "1.0" encoding= "utf-8" ?> <manifest xmlns: android = "http://schemas.android.com/apk/res/android" package= "app.tutorialspoint.com.sample" > <uses-permission android :name= "android.permission.CALL_PHONE" /> <application android :allowBackup= "true" android :icon= "@mipmap/ic_launcher" android :label= "@string/app_name" android :roundIcon= "@mipmap/ic_launcher_round" android :supportsRtl= "true" android :theme= "@style/AppTheme" > <activity android :name= ".MainActivity" > <intent-filter> <action android :name= "android.intent.action.MAIN" /> <category android :name= "android.intent.category.LAUNCHER" /> </intent-filter> </activity> <receiver android :name= ".DeviceAdmin" android :description= "@string/app_description" android :label= "@string/app_name" android :permission= "android.permission.BIND_DEVICE_ADMIN" > <meta-data android :name= "android.app.device_admin" android :resource= "@xml/policies" /> <intent-filter> <action android :name= "android.app.action.DEVICE_ADMIN_ENABLED" /> </intent-filter> </receiver> </application> </manifest>
Let's try to run your application. I assume you have connected your actual Android Mobile device with your computer. To run the app from android studio, open one of your project's activity files and click Run 
icon from the toolbar. Select your mobile device as an option and then check your mobile device which will display your default screen –
Updated on: 30-Jul-2019
3K+ Views
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