android：使用sharedPreference检查Fragment

Question

我在片段中有复选框。选中/取消选中它们后，它们会将值保存到 pref_general.xml 。这工作正常。但是当我尝试检索值并以编程方式检查片段中的框时，它会继续返回可空值。我有输出，所以我可以测试实际读取的内容。

基本上，如何让我的片段从我的首选项文件中检索值？从我所看到的是一个上下文问题，但我看不出我做错了什么。谢谢！

checklist1415_2.java

import android.content.Context;
import android.content.SharedPreferences;
import android.support.design.widget.TabLayout;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;

import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;

import android.widget.CheckBox;
import android.widget.TextView;

public class checklist1415_2 extends AppCompatActivity {


    private SectionsPagerAdapter mSectionsPagerAdapter;

    private ViewPager mViewPager;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_checklist1415_2);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        CheckBox myBox;
        myBox = (CheckBox) findViewById(R.id.edu1415_3);
        mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());

        mViewPager = (ViewPager) findViewById(R.id.container);
        mViewPager.setAdapter(mSectionsPagerAdapter);

        TabLayout tabLayout = (TabLayout) findViewById(R.id.tabs);
        tabLayout.setupWithViewPager(mViewPager);

        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                        .setAction("Action", null).show();
            }
        });

        SharedPreferences loadPref = getPreferences(Context.MODE_PRIVATE);
        String myedu14153 = loadPref.getString("edu1415_3", "0");
        System.out.println("load main pref " + myedu14153);
    }

    public void onChecklistChecked(View view){
        boolean checked = ((CheckBox) view).isChecked();
        String checkedItem = getResources().getResourceEntryName(view.getId());
        SharedPreferences sharedPref = getPreferences(Context.MODE_PRIVATE);
        SharedPreferences.Editor editor = sharedPref.edit();
        String checkVal = "1";
        String pref_key = checkedItem;
        if(checked){
             editor.putString(pref_key, checkVal);
             editor.commit();
        } else {
             editor.putString(pref_key, "-1");
             editor.commit();
        }
        System.out.println(pref_key);
        System.out.println(sharedPref.getString("edu1415_3", "0"));
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.menu_checklist1415_2, menu);
        return true;

    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        int id = item.getItemId();

        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }

    public static class PlaceholderFragment extends Fragment {

        private static final String ARG_SECTION_NUMBER = "section_number";

        public PlaceholderFragment() {
        }

        public static PlaceholderFragment newInstance(int sectionNumber) {
            PlaceholderFragment fragment = new PlaceholderFragment();
            Bundle args = new Bundle();
            args.putInt(ARG_SECTION_NUMBER, sectionNumber);
            fragment.setArguments(args);
            return fragment;
        }

        public static SharedPreferences myPrefs(Context context){
            return context.getSharedPreferences("pref_general", MODE_PRIVATE);
        }

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

            View A = inflater.inflate(R.layout.edu1415, container, false);
            View B = inflater.inflate(R.layout.employ1415, container, false);
            View C = inflater.inflate(R.layout.comm1415, container, false);

            CheckBox check3 = (CheckBox) A.findViewById(R.id.edu1415_3);

            //if(myPrefs(getContext().getString("edu1415_3", "0")=="1"){
            //    check3.setChecked(true);
            //
            // }

            System.out.println("frag pref " + getActivity().getSharedPreferences("pref_general", 0).getString("edu1415_3", "0"));

            switch (getArguments().getInt(ARG_SECTION_NUMBER)){
                case 1:
                    return A;
                case 2:
                    return B;
                case 3:
                    return C;
            }

            return null;
        }
    }

    public class SectionsPagerAdapter extends FragmentPagerAdapter {

        public SectionsPagerAdapter(FragmentManager fm) {
            super(fm);
        }

        @Override
        public Fragment getItem(int position) {
            return PlaceholderFragment.newInstance(position + 1);
        }

        @Override
        public int getCount() {
            return 3;
        }

        @Override
        public CharSequence getPageTitle(int position) {
            switch (position) {
                case 0:
                    return "Education";
                case 1:
                    return "Employment";
                case 2:
                    return "Community";
            }
            return null;
        }
    }
}

pref_general.xml     

    <ListPreference
        android:defaultValue="-1"
        android:entries="@array/pref_example_list_titles"
        android:entryValues="@array/pref_example_list_values"
        android:key="user_age"
        android:negativeButtonText="@null"
        android:positiveButtonText="@null"
        android:title="@string/pref_title_age" />

    <ListPreference
        android:defaultValue="-1"
        android:key="edu1415_3" />

</PreferenceScreen>