隱藏虛擬導航欄

/**
 * 顯示或者隱藏導航欄
 *
 * @param act
 * @param show
 */
public static void hideShowNavigationBar(Activity act, boolean show) {
    if (act == null || act.isFinishing()) {
        return;
    }
    View decorView = act.getWindow().getDecorView();
    int uiOptions;
    if (show) {
        if (GlobalApplication.getInstance().NavigationIsShow()) {
            uiOptions = View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN 
                    | View.SYSTEM_UI_FLAG_LAYOUT_STABLE//重新透明狀態欄
                    | View.SYSTEM_UI_FLAG_VISIBLE;//顯示導航欄，
        } else {
            uiOptions = View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN 
                        | View.SYSTEM_UI_FLAG_LAYOUT_STABLE;//重新透明狀態欄
        }
    } else {
        uiOptions = View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
                | View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY 
                | View.SYSTEM_UI_FLAG_FULLSCREEN;//隱藏導航欄
    }
    decorView.setSystemUiVisibility(uiOptions);
}