Java 状态栏重新出现时检测

我的应用程序全屏运行（沉浸式模式）

状态栏隐藏在顶部

在一些三星手机上，有一支手写笔。如果取下笔，状态栏将重新出现，并且不会消失

我尝试为此事件添加侦听器，但未调用它

 View decorView = getActivity().getWindow().getDecorView();
        decorView.setOnSystemUiVisibilityChangeListener
                (new View.OnSystemUiVisibilityChangeListener()
                {
                    @Override
                    public void onSystemUiVisibilityChange(int visibility) {
                        // Note that system bars will only be "visible" if none of the
                        // LOW_PROFILE, HIDE_NAVIGATION, or FULLSCREEN flags are set.
                        if ((visibility & View.SYSTEM_UI_FLAG_FULLSCREEN) == 0) {
                            // TODO: The system bars are visible. Make any desired
                            // adjustments to your UI, such as showing the action bar or
                            // other navigational controls.

                            System.out.print("Change event");
                        } else {
                            // TODO: The system bars are NOT visible. Make any desired
                            // adjustments to your UI, such as hiding the action bar or
                            // other navigational controls.
                            System.out.print("Change event");
                        }
                    }
                });

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你知道我如何知道状态栏是否重新出现了吗？

在我的活动中，我这样做是为了让它重新隐藏状态栏：

@Override
    public void onWindowFocusChanged(boolean hasFocus)
    {
        System.out.println("Gotcha");
        super.onWindowFocusChanged(hasFocus);

        final Handler handler = new Handler();
        handler.postDelayed(new Runnable()
        {
            @Override
            public void run() {
                System.out.println("Hiding");
                _root.setSystemUiVisibility(View.SYSTEM_UI_FLAG_FULLSCREEN
                        | View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY
                        | View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
                        | View.SYSTEM_UI_FLAG_FULLSCREEN
                        | View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
                        | View.SYSTEM_UI_FLAG_LAYOUT_STABLE);
            }
        }, 6000);
    }

---

在我的活动中，我这样做是为了让它重新隐藏状态栏：

@Override
    public void onWindowFocusChanged(boolean hasFocus)
    {
        System.out.println("Gotcha");
        super.onWindowFocusChanged(hasFocus);

        final Handler handler = new Handler();
        handler.postDelayed(new Runnable()
        {
            @Override
            public void run() {
                System.out.println("Hiding");
                _root.setSystemUiVisibility(View.SYSTEM_UI_FLAG_FULLSCREEN
                        | View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY
                        | View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
                        | View.SYSTEM_UI_FLAG_FULLSCREEN
                        | View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
                        | View.SYSTEM_UI_FLAG_LAYOUT_STABLE);
            }
        }, 6000);
    }