无法更新片段内的RecyclerView

Question

我有一个活动，该活动使用ViewPager包含2个片段。在其中一个片段中，我有一个recyclerView。到现在为止，当我第一次运行该应用程序时，视图将正确显示。片段向Web服务发出请求，并将数据加载到片段的recyclerview中，一切正常。现在我的问题是我必须通过传递一个整数来过滤从MainActivity加载到回收器视图中的数据，但是回收器视图不会更新。

这是我的代码：

我如何在MainActivity中设置viewPager：

        setSupportActionBar(toolbar);
        ViewPagerAdapter adapterpager = new ViewPagerAdapter(getSupportFragmentManager(),context);
        viewPager.setAdapter(adapterpager);
        tabLayout.setupWithViewPager(viewPager);

ViewPagerAdapter：

public class ViewPagerAdapter extends FragmentPagerAdapter {

    Context context;
    public ViewPagerAdapter(FragmentManager fm, Context context) {
        super(fm);
        this.context=context;
    }

    @Override
    public Fragment getItem(int position) {
        ActivitiesFragment activitiesFragment = new ActivitiesFragment(context);
        ArticlesFragment articlesFragment = new ArticlesFragment(context);
        Fragment fragment = new Fragment();

        if (position==0) {
            fragment = activitiesFragment;
        }else if (position==1){
            fragment = articlesFragment;
        }
        return fragment;
    }

    @Override
    public int getCount() {
        return 2;
    }

    @Nullable
    @Override
    public CharSequence getPageTitle(int position) {
        position = position+1;
        String tabTittle="Activities";
        if (position==2){
            tabTittle = "Articles";
        }
        return tabTittle;
    }
}

我的活动片段：

public class ActivitiesFragment extends Fragment implements ActivitiesResponse {

    private RecyclerView activityRecycler;
    private RequestMethods req;
    private String skillId="1";
    private String babyId="50";
    Context context;
    private ActivitiesRecyclerAdapter activitiesRecyclerAdapter;

    public ActivitiesFragment(Context context) {
        // Required empty public constructor
        this.context=context;
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View v = inflater.inflate(R.layout.fragment_activities, container, false);
        activityRecycler = v.findViewById(R.id.activities_recycler);

        LinearLayoutManager linearLayoutManager = new LinearLayoutManager(context);
        linearLayoutManager.setOrientation(RecyclerView.VERTICAL);
        activityRecycler.setLayoutManager(linearLayoutManager);

        req = new RequestMethods(context);
        req.getActivities(skillId,babyId,0);
        req.onActivityResponse(this);
        return v;
    }

    @Override
    public void getActivities(List<Activity> list, int age) {

        List<Activity> activityList = new ArrayList<>();
        int listPos=0;
        if (age==0){
            activityList = list;
        }else{
        for (int x =0;x<list.size();x++){
            if (list.get(x).getAge()==age){
                activityList.add(listPos,list.get(x));
                listPos++;
            }
        }
        }
        activitiesRecyclerAdapter = new ActivitiesRecyclerAdapter(activityList, context, new OnItemActivityClickListener() {
            @Override
            public void onItemClick(List<Activity> list, int position) {
                Log.e("response_data","Click "+list.get(position).getName());
            }
        });

        activityRecycler.setAdapter(activitiesRecyclerAdapter);
    }
    public void requestActivities(int age){
        RequestMethods request = new RequestMethods(context);
        request.onActivityResponse(this);
        request.getActivities(skillId,babyId,age);
    }
}

我尝试使用Override方法getActivities(List<Activity> list, int age){}更新Recyclerview，但到目前为止没有任何效果。我被困了几个小时，请帮忙！