<!--android:persistent="false" 有啥用-->
<PreferenceScreen
android:title="Screen preference"
android:summary="Shows another screen of preferences"
>
<CheckBoxPreference
android:title="Toggle preference"
android:summary="Preference that is on the next screen but same hierarchy"
android:key="check_toggle_key"
>
</CheckBoxPreference>
</PreferenceScreen>
<Preference android:title="Intent preference"
android:summary="Launches an Activity from an Intent">
<intent android:action="android.intent.action.VIEW"
android:data="http://www.baidu.com" />
</Preference>
</PreferenceCategory>
<PreferenceCategory android:title="Preference attributes">
<CheckBoxPreference
android:title="Parent checkbox preference"
android:summary="This is visually a parent "
android:key="check_parent_key">
</CheckBoxPreference>
<CheckBoxPreference
android:title="Child checkbox preference"
android:summary="This is visually a child "
android:key="check_child_key"
android:dependency="check_parent_key">
</CheckBoxPreference>
</PreferenceCategory>