将PreferenceScreen添加到底部NavBar Android中

Question

我试图将PreferenceFragment添加到底部导航栏中，但是每次应用程序加载片段时，都会引发错误。我的问题是，如何将SettingsFragment添加到现有的底部导航栏中？我应该更改填充栏的方式吗？

E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.eduardo.proyectolainne, PID: 21633
java.lang.NullPointerException: Attempt to invoke virtual method 'void android.support.v7.widget.RecyclerView.setAdapter(android.support.v7.widget.RecyclerView$Adapter)' on a null object reference
    at android.support.v7.preference.PreferenceFragmentCompat.bindPreferences(PreferenceFragmentCompat.java:533)
    at android.support.v7.preference.PreferenceFragmentCompat.onViewCreated(PreferenceFragmentCompat.java:324)
    at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1471)
    at android.support.v4.app.FragmentManagerImpl.moveFragmentToExpectedState(FragmentManager.java:1784)
    at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1852)
    at android.support.v4.app.BackStackRecord.executeOps(BackStackRecord.java:802)
    at android.support.v4.app.FragmentManagerImpl.executeOps(FragmentManager.java:2625)
    at android.support.v4.app.FragmentManagerImpl.executeOpsTogether(FragmentManager.java:2411)
    at android.support.v4.app.FragmentManagerImpl.removeRedundantOperationsAndExecute(FragmentManager.java:2366)
    at android.support.v4.app.FragmentManagerImpl.execSingleAction(FragmentManager.java:2243)
    at android.support.v4.app.BackStackRecord.commitNowAllowingStateLoss(BackStackRecord.java:654)
    at android.support.v4.app.FragmentStatePagerAdapter.finishUpdate(FragmentStatePagerAdapter.java:168)
    at android.support.v4.view.ViewPager.populate(ViewPager.java:1244)
    at android.support.v4.view.ViewPager.setCurrentItemInternal(ViewPager.java:669)
    at android.support.v4.view.ViewPager.setCurrentItemInternal(ViewPager.java:631)
    at android.support.v4.view.ViewPager.setCurrentItem(ViewPager.java:612)
    at com.example.eduardo.proyectolainne.MainActivity$1.onTabSelected(MainActivity.java:42)
    at com.aurelhubert.ahbottomnavigation.AHBottomNavigation.updateItems(AHBottomNavigation.java:590)
    at com.aurelhubert.ahbottomnavigation.AHBottomNavigation.access$000(AHBottomNavigation.java:52)
    at com.aurelhubert.ahbottomnavigation.AHBottomNavigation$2.onClick(AHBottomNavigation.java:437)
    at android.view.View.performClick(View.java:5619)
    at android.view.View$PerformClick.run(View.java:22298)
    at android.os.Handler.handleCallback(Handler.java:754)
    at android.os.Handler.dispatchMessage(Handler.java:95)
    at android.os.Looper.loop(Looper.java:165)
    at android.app.ActivityThread.main(ActivityThread.java:6375)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:883)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:773)

SettingsFragment.java

    package com.example.eduardo.proyectolainne;

    import android.os.Bundle;
    import android.support.v14.preference.PreferenceFragment;
    import android.support.v7.preference.ListPreference;
    import android.support.v7.preference.Preference;
    import android.support.v7.preference.PreferenceFragmentCompat;
    import android.view.LayoutInflater;
    import android.view.View;
    import android.view.ViewGroup;


    public class SettingsFragment extends PreferenceFragmentCompat {
        @Override
        public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
            setPreferencesFromResource(R.xml.preference_screen, rootKey);
        }

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroupcontainer, Bundle savedInstanceState) {

            return inflater.inflate(R.layout.fragment_settings, container, false);
        }
    }

preference_screen.xml

    <?xml version="1.0" encoding="utf-8"?>
    <PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">

        <PreferenceCategory
             android:title="@string/title_first_section">

            <CheckBoxPreference
                android:key="checkbox_preference"
                android:title="@string/title_checkbox_preference"
                android:defaultValue="@string/default_checkbox_preference"/>

            <EditTextPreference
                android:key="edittext_preference"
                android:title="@string/title_edittext_preference"
                android:summary="@string/summary_edittext_preference"
                android:dialogTitle="@string/dialog_title_edittext_preference"
                android:dependency="checkbox_preference" />

        </PreferenceCategory>

        <PreferenceCategory
            android:title="@string/title_second_section">


            <Preference
                android:title="@string/title_intent_preference">
                <intent android:action="android.intent.action.VIEW"
                    android:data="http://codepath.com/" />
            </Preference>

        </PreferenceCategory>

    </PreferenceScreen>

MainActivity.java

package com.example.eduardo.proyectolainne;

import android.graphics.Color;
import android.icu.text.RelativeDateTimeFormatter;
import android.os.Bundle;
import android.preference.PreferenceScreen;
import android.support.annotation.ColorRes;
import android.support.annotation.NonNull;
import android.support.v4.app.Fragment;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AppCompatActivity;

import com.aurelhubert.ahbottomnavigation.AHBottomNavigation;
import com.aurelhubert.ahbottomnavigation.AHBottomNavigationItem;

public class MainActivity extends AppCompatActivity {

    private final int[] colors = {R.color.bottomtab_0, R.color.bottomtab_1, R.color.bottomtab_2};

    private NoSwipePager viewPager;
    private AHBottomNavigation bottomNavigation;
    private BottomBarAdapter pagerAdapter;

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

        setupViewPager();

        bottomNavigation = (AHBottomNavigation) findViewById(R.id.bottom_navigation);
        setupBottomNavBehaviors();
        setupBotomNavStyle();

        addBottomNavigationItems();
        bottomNavigation.setCurrentItem(0);

        bottomNavigation.setOnTabSelectedListener(new AHBottomNavigation.OnTabSelectedListener() {
            @Override
            public boolean onTabSelected(int position, boolean wasSelected) {

                if (!wasSelected) {
                    viewPager.setCurrentItem(position);
                }

                int lastItemPos = bottomNavigation.getItemsCount() - 1;
                return true;
            }
        });

    }

    private void setupViewPager() {
        viewPager = (NoSwipePager) findViewById(R.id.viewpager);
        viewPager.setPagingEnabled(false);
        pagerAdapter = new BottomBarAdapter(getSupportFragmentManager());

        pagerAdapter.addFragments(createHomeFragment(R.color.bottomtab_0));
        pagerAdapter.addFragments(createOrdersFragment(R.color.bottomtab_1));
        pagerAdapter.addFragments(createSettingsFragmet());

        viewPager.setAdapter(pagerAdapter);
    }

    @NonNull
    private HomeFragment createHomeFragment(int color) {
        HomeFragment fragment = new HomeFragment();
        fragment.setArguments(passFragmentArguments(fetchColor(color)));
        return fragment;
    }

    @NonNull
    private OrdersFragment createOrdersFragment(int color) {
        OrdersFragment fragment = new OrdersFragment();
        fragment.setArguments(passFragmentArguments(fetchColor(color)));
        return fragment;
    }

    @NonNull
    private SettingsFragment createSettingsFragmet() {
        SettingsFragment fragment = new SettingsFragment();
        return fragment;
    }


    @NonNull
    private Bundle passFragmentArguments(int color) {
        Bundle bundle = new Bundle();
        bundle.putInt("color", color);
        return bundle;
    }

    public void setupBottomNavBehaviors() {
        bottomNavigation.setTranslucentNavigationEnabled(false);
    }

    private void setupBotomNavStyle() {
        bottomNavigation.setDefaultBackgroundColor(Color.WHITE);
        bottomNavigation.setAccentColor(fetchColor(R.color.bottomtab_0));
        bottomNavigation.setInactiveColor(fetchColor(R.color.bottomtab_item_resting));

        bottomNavigation.setColoredModeColors(Color.WHITE,
                fetchColor(R.color.bottomtab_item_resting));

        bottomNavigation.setColored(true);

        bottomNavigation.setTitleState(AHBottomNavigation.TitleState.ALWAYS_SHOW);
    }

    private void addBottomNavigationItems() {
        AHBottomNavigationItem item1 = new AHBottomNavigationItem(R.string.tab_1, R.drawable.birthday_cake_ic, colors[0]);
        AHBottomNavigationItem item2 = new AHBottomNavigationItem(R.string.tab_2, R.drawable.baseline_shopping_cart_white_18dp, colors[1]);
        AHBottomNavigationItem item3 = new AHBottomNavigationItem(R.string.tab_3, R.drawable.baseline_settings_white_18dp, colors[2]);

        bottomNavigation.addItem(item1);
        bottomNavigation.addItem(item2);
        bottomNavigation.addItem(item3);
    }

    private int fetchColor(@ColorRes int color) {
        return ContextCompat.getColor(this, color);
    }
}