Locking phone

[rfresh]

Is there code to lock my phone? I'm interested in this in case my phone is stolen and I'm wondering if I can lock it with my app?

I've searched the forum and the docs but didn't see anything about programatically locking your phone.

Thanks...

 

[rfresh]

I thought I'd bump this one since a week has gone by with no responses yet...thanks...

 

[warwound]

Why not just install Avast Mobile Security and enable it's anti-theft module?

I have that installed and activated on my ZTE Blade and am pretty confident that only a thief with a good knowledge of flashing a new ROM could use my mobile if they stole it.

Martin.

 

[rfresh]

I'd like to try and implement this capability on my apps for my own learning and knowledge with B4A.

 

[warwound]

OK.

But there's many things to consider.

The first thing is how to stop a thief from simply downloading the latest official firmware for your mobile and simply (re)flashing your mobile.

Your code would have to somehow survive such a reflash.

Avast has two anti theft modes, one for rooted devices and one for non-rooted devices.

The mode for non-rooted devices is far less secure than the mode for rooted devices as Avast doesn't have the permission to write system files to make a complete reflash less effective.

Whereas the mode for rooted devices employs various techniques to write to the system partition and hopefully make a reflash noneffective in wiping Avast from the device.

I'd suggest you install Avast on a device and go through the anti theft setp up procedure to get some ideas about what steps you need to take to fully protect your device.

Then look at implementing those steps in your own application - and remove Avast when it's no longer required.

Martin.

 

[rfresh]

>The first thing is how to stop a thief from simply downloading the
>latest official firmware for your mobile and simply (re)flashing your mobile.

If the person who steals my phone knows how to install new firmware by re-flashing my phone, then more power to them.

I'm just interested in being able to Lock my phone (via code and without rooting) from someone who isn't an Android developer or Linux geek. In other words, from a casual smart phone user.

 

[rfresh]

It's been a two weeks so I thought I'd bump this topic on phone locking. Anyone know if we can lock a phone using code?

Thanks...

 

[rfresh]

I read that we cannot lock our phones as a security feature, but we can lock the screen using this pure Android java code:

KeyguardManager mgr = (KeyguardManager)getSystemService(Activity.KEYGUARD_SERVICE); 
KeyguardLock lock = mgr.newKeyguardLock(KEYGUARD_SERVICE); 
lock.reenableKeyguard();

The comment with this code was that this will also require the "Disable Keyguard" permission in your manifest file.

Can someone convert this code into something B4A can use? I'd like to test it and see if it will screen blank my Droid2 phone.

The article I read was here.

BTW, I notice that some apps in the Android Play store say they can lock your phone. I wonder if they can do that only for rooted phones?

Thanks...

 

[Erel]

This is the equivalent code:

Sub LockScreen
   Dim r As Reflector
   r.Target = r.GetContext
   r.Target = r.RunMethod2("getSystemService", "keyguard", "java.lang.String")
   r.Target = r.RunMethod2("newKeyguardLock", "keyguard", "java.lang.String")
   r.RunMethod("reenableKeyguard")
End Sub

You should add this code to the manifest editor:

AddPermission(android.permission.DISABLE_KEYGUARD)

It didn't work on the device I tested it (maybe because I don't have a password set).

 

[rfresh]

Thanks Erel. I will try this out on my Droid2 and Droid3 later today.

Update: I could not get it to lock my screen either. I set a PIN security code. Tested that it works. Then ran your code. The screen didn't lock. This was on my Droid2. I did the same thing on my Droid3 with the same results: nothing happened. And I did add the manifest statement.

 

[salmander]

Hi rfresh,

I am guessing you still haven't found a working solution yet. So I am posting my findings on this topic. I have managed to disable the keyguard, but now I can't re-enable it. Well here is my code;

Sub keyguard(enable As Boolean)
    Log("keyguard sub initiated")
    Dim r As Reflector
    r.Target = r.GetContext
    r.Target = r.RunMethod2("getSystemService", "keyguard", "java.lang.String")
    r.Target = r.RunMethod2("newKeyguardLock", "keyguard", "java.lang.String")
    If enable = False Then
   Log("disabling the keyguard")
       r.RunMethod("disableKeyguard")
    Else
   Log("enabling the keyguard")
   r.RunMethod("reenableKeyguard")
    End If
End Sub

Hope this helps, and if you do find out how to re-enable the lock-screen, do post back please.

 

[Erel]

Note that you can lock the device with the new Administrator library.

 

[salmander]

Thanks Erel, I was thinking of the same thing. But this should work according to android developer documentation. Have you tested it?

cheers

 

[Erel]

Similar code didn't work for me and other users: http://www.b4x.com/forum/basic4android-updates-questions/17196-locking-phone.html

 

[salmander]

This is the equivalent code:

   r.RunMethod("reenableKeyguard")

It didn't work on the device I tested it (maybe because I don't have a password set).

Similar code didn't work for me and other users: http://www.b4x.com/forum/basic4android-updates-questions/17196-locking-phone.html

Note that you and rfresh were using "reenableKeyguard" method to disable the lock screen, which is actually use to enable the lock-screen. If you use my code, it should work.

I tested on tablet and my phone and both are working with disabling the lock screen. But the "reenableKeyguard" method seems to be not working.

 

[salmander]

I just tested the administrator library to re-enable the keylock. All it does is turns off the screen, when you turn it back on , the screen lock doesn't shows up and the activity resumes. I checked it few times if the application is set as administrator and indeed it is. I believe its the reenableKeyguard method. If I close the application using ExitApplication, then the Lock Screen behaves normally (as in shows after the screen turns on).

 

[Erel]

The administrator library cannot change the lock screen. It can activate the current lock screen. The original question of this thread was how to programmatically lock the screen.

 

[salmander]

Yes it is not activating the lock screen, if the screen lock has been disabled by reflection method.