I've resolved!!!!
I used this code:
Dim jo As JavaObject = Activity
Dim Window As JavaObject = jo.RunMethodJO("getContext", Null).RunMethod("getWindow", Null)
Window.RunMethod("addFlags", Array As Object(524288)) 'FLAG_SHOW_WHEN_LOCKED
Window.RunMethod("addFlags", Array As Object(128)) 'FLAG_KEEP_SCREEN_ON
F.