Android 響應(yīng)UI可見性的變化

編寫:K0ST - 原文:http://developer.android.com/training/system-ui/visibility.html

本節(jié)課將教你如果注冊監(jiān)聽器來監(jiān)聽系統(tǒng)UI可見性的變化。這個(gè)方法在將系統(tǒng)欄與你自己的UI控件進(jìn)行同步操作時(shí)很有用。

注冊監(jiān)聽器

為了獲取系統(tǒng)UI可見性變化的通知，我們需要對(duì)View注冊View.OnSystemUiVisibilityChangeListener監(jiān)聽器。通常上來說，這個(gè)View是用來控制導(dǎo)航的可見性的。

例如你可以添加如下代碼在onCreate中

View decorView = 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.
        } 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.
        }
    }
});

保持系統(tǒng)欄和UI同步是一種很好的實(shí)踐方式，比如當(dāng)狀態(tài)欄顯示或隱藏的時(shí)候進(jìn)行ActionBar的顯示和隱藏等等。