下面是使用介紹必須放到setContentView前面

    /**
     * 隱藏虛擬按鍵，並且設定成全屏
     */
    protected void hideBottomUIMenu() {
        if (Build.VERSION.SDK_INT >= 19) {
            //for new api versions.
            View decorView = getWindow().getDecorView();
            int uiOptions = View.SYSTEM_UI_FLAG_LAYOUT_STABLE
                    | View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
                    | View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
                    | View.SYSTEM_UI_FLAG_HIDE_NAVIGATION // hide nav bar
                    | View.SYSTEM_UI_FLAG_FULLSCREEN // hide status bar
                    | View.SYSTEM_UI_FLAG_IMMERSIVE;
            decorView.setSystemUiVisibility(uiOptions);
            getWindow().addFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_NAVIGATION);
        }
    }