Android：检测导航栏可见性

如何检测导航栏的存在并将其隐藏？

In my onCreate() I call hideNavigationBar()方法来隐藏导航栏，然后我注册一个侦听器，以便在用户触摸屏幕上的任何位置时每次导航栏变得可见时隐藏导航栏（如文档。当导航栏在触摸事件后变得可见时hideNavigationBar()方法被监听器再次调用，但没有效果，栏仍然可见。

这是我的onCreated() method:

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        hideNavigationBar();

        View decorView = getWindow().getDecorView();
        decorView.setOnSystemUiVisibilityChangeListener
                (new View.OnSystemUiVisibilityChangeListener() {
                    @Override
                    public void onSystemUiVisibilityChange(int visibility) {
                        if ((visibility & View.SYSTEM_UI_FLAG_FULLSCREEN) == 0) {
                            Toast.makeText(getApplicationContext(), "Visible", Toast.LENGTH_SHORT).show();
                            hideNavigationBar();
                        } else {
                            Toast.makeText(getApplicationContext(), "Not visible", Toast.LENGTH_SHORT).show();
                        }
                    }
                });
    }

这是我的hideNavigationBar() method:

 private void hideNavigationBar() {

        Toast.makeText(getApplicationContext(), "hideNavigationBar()", Toast.LENGTH_SHORT).show();

        View decorView = getWindow().getDecorView();
        int uiOptions = View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
                | View.SYSTEM_UI_FLAG_FULLSCREEN;
        decorView.setSystemUiVisibility(uiOptions);
    }

如何在每次导航栏可见时将其隐藏？

Thanks

您可以将此代码添加到活动的 onCreate() 方法中：

      View decorView = getWindow().getDecorView();
    decorView.setOnSystemUiVisibilityChangeListener
            (new View.OnSystemUiVisibilityChangeListener() {
                @Override
                public void onSystemUiVisibilityChange(int visibility) {
                    if ((visibility & View.SYSTEM_UI_FLAG_HIDE_NAVIGATION) == 0) {                
                        // TODO: The navigation bar is visible. Make any desired
                        // adjustments to your UI, such as showing the action bar or
                        // other navigational controls.
                        hideNavigationBar() 

                    } else {
                        // TODO: The navigation bar is NOT visible. Make any desired
                        // adjustments to your UI, such as hiding the action bar or
                        // other navigational controls.
                    }
                }
            });

通常最好的做法是使 UI 与系统栏可见性的变化保持同步。例如，您可以使用此侦听器来隐藏和显示操作栏，同时隐藏和显示状态栏。Android-响应 UI 可见性变化