How to programmatically lock screen in Android? [duplicate]

Answer 1

Check this class : com.android.internal.policy.impl.LockScreen

Referenced from here: Can you lock screen from your app?

Also check code for enabling and disabling lock Screen in Android. (Referenced from here)

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

For locking the screen use,

lock.reenableKeyguard();

and for disabling the lock use,

lock.disableKeyguard()

Answer 2

In order to do this you need to use the Device Administration API that was added in (I think) 2.2. Once your app is registered on the device as a device administrator, you can then use DevicePolicyManager.lockNow() to lock the screen. The DeviceAdmin sample application in the SDK is a good place to look as well.