Just it, I have found how to hide title bar but I didnt find how hide / show the status bar pressing a button fr example. It is possible? thanks!
To hide a status Bar
Use this code in your Activity
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams.FLAG_FULLSCREEN);
Change Application theme in Manifest file as below
android:theme="@android:style/Theme.Black.NoTitleBar"