I want to disable the screen (Android 4.4.2) when I press a button. Is that possible without rooting the device? I have tried the code below, but it doesn't work (it throws exception).
private DevicePolicyManager mDPM;
OnCreate:
mDPM = (DevicePolicyManager)getSystemService(Context.DEVICE_POLICY_SERVICE);
button listener:
mDPM.lockNow();
AndroidManifest.xml:
<intent-filter>
<action android:name="android.app.action.DEVICE_ADMIN_ENABLED" />
<action android:name="android.app.action.DEVICE_ADMIN_DISABLED" />
</intent-filter>
Stack Trace:
10-03 20:32:50.187 4172-4172/com.microchip.android.BasicAccessoryDemo_API12 E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.microchip.android.BasicAccessoryDemo_API12, PID: 4172
java.lang.SecurityException: No active admin owned by uid 10175 for policy #3
at android.os.Parcel.readException(Parcel.java:1465)
at android.os.Parcel.readException(Parcel.java:1419)
at android.app.admin.IDevicePolicyManager$Stub$Proxy.lockNow(IDevicePolicyManager.java:1594)
at android.app.admin.DevicePolicyManager.lockNow(DevicePolicyManager.java:1076)
at com.microchip.android.BasicAccessoryDemo_API12.PasswordActivity$1.onClick(PasswordActivity.java:209)
at android.view.View.performClick(View.java:4442)
at android.view.View$PerformClick.run(View.java:18471)
at android.os.Handler.handleCallback(Handler.java:733)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5103)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:790)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:606)
at dalvik.system.NativeStart.main(Native Method)
I found a code which can lock the device (if it has code protection) and consequently to disable the screen. Below is the code.
On the Manifest put the below code:
<receiver
android:name=".MyDeviceAdminReceiver"
android:permission="android.permission.BIND_DEVICE_ADMIN" >
<meta-data
android:name="android.app.device_admin"
android:resource="@xml/my_admin" />
<intent-filter>
<action android:name="android.app.action.DEVICE_ADMIN_ENABLED" />
</intent-filter>
</receiver>
Put this declaration in onCreate's Activity:
static final int RESULT_ENABLE = 1;
Put the below code in Button Listener:
// Enable the Administrator mode.
DevicePolicyManager deviceManger = (DevicePolicyManager) getSystemService(
Context.DEVICE_POLICY_SERVICE );
ActivityManager activityManager = (ActivityManager) getSystemService(
Context.ACTIVITY_SERVICE );
ComponentName compName = new ComponentName( getApplicationContext( ),
MyDeviceAdminReceiver.class);
Intent device_policy_manager_Int = new Intent( DevicePolicyManager
.ACTION_ADD_DEVICE_ADMIN );
device_policy_manager_Int.putExtra( DevicePolicyManager.EXTRA_DEVICE_ADMIN,
compName );
device_policy_manager_Int.putExtra( DevicePolicyManager.EXTRA_ADD_EXPLANATION,
"Additional text explaining why this needs to be added." );
startActivityForResult( device_policy_manager_Int, RESULT_ENABLE );
// Check if the Administrator is enabled.
boolean active = deviceManger.isAdminActive(compName);
if ( active ) {
Log.i("isAdminActive", "Admin enabled!");
// If admin is enable - Lock device.
deviceManger.lockNow( );
}