step1:调用Activity成员函数dispatchKeyEvent public boolean dispatchKeyEvent(KeyEvent event) { // Let action bars open menus in response to the menu key prioritized over // the window handling it if (event.getKeyCode() == KeyEvent.KEYCODE_MENU && mActionB…
Class Overview An activity is a single, focused thing that the user can do. Almost all activities interact with the user, so the Activity class takes care of creating a window for you in which you can place your UI with setContentView(View). While ac…