android - How can i disable all bottom navigation button for lockscreen..? -

i'm creating lock screen application. , activity work perfectly, when screen lock activity comes on screen on, home , task navigation button works. button not working because have return nothing in onbackpressed() method.

now don't know how disable navigation buttons work in lockscreen application.

i have tried this:

@override  public boolean onkeydown(int keycode, keyevent event) {   if ((keycode == keyevent.keycode_volume_down)||(keycode ==   keyevent.keycode_power)||(keycode == keyevent.keycode_volume_up)||(keycode == keyevent.keycode_camera)) {     //this can stuff    return false; } if (keycode == keyevent.keycode_menu) { //do code here // if want block return false return false; } if (keycode == keyevent.keycode_home) { //do code here // if want block return false return false; } 

but button stops working other remain is.