I want to turn off / lock the screen of my device programmatically.
For the moment, when I try :
DevicePolicyManager mDPM = (DevicePolicyManager)getSystemService(Context.DEVICE_POLICY_SERVICE);
mDPM.lockNow();
I have this error :
java.lang.SecurityException: No active admin owned by uid 10176 for policy #3
This is my AndroidManifest.xml :
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="opteamit.com.belami" >
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="com.google.android.c2dm.permission.RECEIVE" />
<uses-permission android:name="android.permission.WAKE_LOCK" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
<uses-feature android:name="android.hardware.location.gps" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW"/>
<uses-permission android:name="android.permission.CAMERA"/>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
<uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW" />
<application...
What is wrong ?
Well something with high necessity can't finished with two lines of code, lock off screen required device admin. you may follow this :
private void lock() {
PowerManager pm = (PowerManager)getSystemService(Context.POWER_SERVICE);
if (pm.isScreenOn()) {
DevicePolicyManager policy = (DevicePolicyManager)
getSystemService(Context.DEVICE_POLICY_SERVICE);
try {
policy.lockNow();
} catch (SecurityException ex) {
Toast.makeText(
this,
"must enable device administrator",
Toast.LENGTH_LONG).show();
ComponentName admin = new ComponentName(context, AdminReceiver.class);
Intent intent = new Intent(
DevicePolicyManager.ACTION_ADD_DEVICE_ADMIN).putExtra(
DevicePolicyManager.EXTRA_DEVICE_ADMIN, admin);
context.startActivity(intent);
}
}
}
and AdminReceiverClass:
public class AdminReceiver extends DeviceAdminReceiver {
public static final String ACTION_DISABLED = "device_admin_action_disabled";
public static final String ACTION_ENABLED = "device_admin_action_enabled";
@Override
public void onDisabled(Context context, Intent intent) {
super.onDisabled(context, intent);
LocalBroadcastManager.getInstance(context).sendBroadcast(
new Intent(ACTION_DISABLED));
}
@Override
public void onEnabled(Context context, Intent intent) {
super.onEnabled(context, intent);
LocalBroadcastManager.getInstance(context).sendBroadcast(
new Intent(ACTION_ENABLED));
}
}
also we need declares the security policies used in metadata so for examples with Path android:resource="@xml/device_admin_sample" :
<device-admin xmlns:android="http://schemas.android.com/apk/res/android">
<uses-policies>
<limit-password />
<watch-login />
<reset-password />
<force-lock />
<wipe-data />
<expire-password />
<encrypted-storage />
<disable-camera />
</uses-policies>
</device-admin>
in our case we just need :
<?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>`
Now declare it in our manifist.xml :
<receiver
android:name=".AdminReceiver"
android:label="@string/device_admin"
android:description="@string/device_admin_description"
android:permission="android.permission.BIND_DEVICE_ADMIN">
<meta-data
android:name="android.app.device_admin"
android:resource="@xml/device_admin_sample" />
<intent-filter>
<action android:name="android.app.action.DEVICE_ADMIN_ENABLED" />
</intent-filter>
</receiver>`
Hope it will Help you.