如何管理MultiSelectListPreference以保存对SharedPreferences的用户选择？

Question

我正在尝试使MultiSelectListPreference起作用，但是它不能保存，请记住用户的选择。 onSharedPreferenceChanged仅适用于EditText和ListPreference，MultiSelectListPreference不会调用它，因此...

我尝试实现Preference.OnPreferenceChangeListener并重写onPreferenceChange，并且尝试以不同的方式调用它，就像您在代码中将看到的那样，但未调用它们。

package com.adc.settingsapp;


import android.content.Context;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.view.MenuItem;
import android.widget.Toast;

import androidx.preference.EditTextPreference;
import androidx.preference.ListPreference;
import androidx.preference.MultiSelectListPreference;
import androidx.preference.Preference;
import androidx.preference.PreferenceFragmentCompat;
import androidx.preference.PreferenceManager;

import java.util.Arrays;
import java.util.HashSet;
import java.util.Set;


public class SettingsFragment extends PreferenceFragmentCompat implements SharedPreferences.OnSharedPreferenceChangeListener, Preference.OnPreferenceChangeListener {

    SharedPreferences sharedPreferences;

    public SettingsFragment() {
        // Required empty public constructor
    }

    @Override
    public void onCreatePreferences(Bundle bundle, String s) {

        addPreferencesFromResource(R.xml.pref_configuration);

        sharedPreferences = PreferenceManager.getDefaultSharedPreferences(getActivity());

        onSharedPreferenceChanged(sharedPreferences, "pref_display_name");
        onSharedPreferenceChanged(sharedPreferences, "pref_language");
        onSharedPreferenceChanged(sharedPreferences, "pref_multilist");

        setDefaultValuesForMultiSelectListPreference();

        MultiSelectListPreference mMultiSelectListPreference = (MultiSelectListPreference) findPreference("pref_multilist");

        mMultiSelectListPreference.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener() {

            @Override
            public boolean onPreferenceChange(Preference preference, Object newValue) {

                Toast.makeText(getActivity(), "onPreferenceCHangeLIstner", Toast.LENGTH_SHORT);

                return true;
            }
        });

    }



    // set the default values
    private void setDefaultValuesForMultiSelectListPreference() {

        MultiSelectListPreference mMultiSelectListPreference = (MultiSelectListPreference) findPreference("pref_multilist");

        Set<String> value = new HashSet<String>(Arrays.asList("Value1", "Value3"));
        mMultiSelectListPreference.setValues(value);

    }

    @Override
    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        getPreferenceScreen().getSharedPreferences().registerOnSharedPreferenceChangeListener(this);

    }

    // evocato quando cambiano i settaggi,
    // evocato anche quando si carica l'activity per la prima volta,
    // probabilmente lo chiama onSharedPreferenceChanged in onCreatePreference
    @Override
    public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) {

        Preference preference = findPreference(key);

        //Toast.makeText(getActivity(), "onSharedPreferenceChanged", Toast.LENGTH_SHORT).show();

        if (preference instanceof ListPreference) {

            ListPreference listPreference = (ListPreference) preference;

            int prefIndex = listPreference.findIndexOfValue(sharedPreferences.getString(key, ""));

            if (prefIndex >= 0) {

                preference.setSummary(listPreference.getEntries()[prefIndex]);

            }

        } else if( preference instanceof EditTextPreference) {

            preference.setSummary(sharedPreferences.getString(key, "NoName"));

        }

    }

    @Override
    public boolean onPreferenceChange(Preference preference, Object newValue) {

        Toast.makeText(getActivity(), "onPreferenceChange", Toast.LENGTH_SHORT).show();

        return true;

    }

}

一旦我了解如何管理用户选择，便会保存它（基于SharedPreference）。