BasePreferenceFragment.java 文件源码

@Override
public boolean onPreferenceChange(Preference preference, Object newValue) {
    String value = newValue.toString();
    if (preference instanceof ListPreference) {
        ListPreference listPreference = (ListPreference) preference;
        int index = listPreference.findIndexOfValue(value);
        preference.setSummary(index >= 0 ? listPreference.getEntries()[index] : null);
    } else if (preference instanceof RingtonePreference) {
        if (TextUtils.isEmpty(value)) {
            preference.setSummary(R.string.pref_summary_silent);
        } else {
            Ringtone ringtone = RingtoneManager.getRingtone(preference.getContext(), Uri.parse(value));
            if (ringtone != null) {
                preference.setSummary(ringtone.getTitle(preference.getContext()));
            } else {
                preference.setSummary(null);
            }
        }
    } else {
        preference.setSummary(value);
    }
    return true;
}