将适配器从主要活动设置为其片段

Question

免责声明：我是菜鸟

这里的场景是，我有一个主要活动，充当我的三个片段的中介者，并且在三个片段中有各自的回收者视图。

我的问题是我需要将所有回收站视图的适配器中的三个碎片设置为主，这无法通过意图/捆绑来完成，因为它们都同时运行，而且我似乎无法调用回收站视图来自主要活动的3个碎片。

主要例子

public class classList_index extends AppCompatActivity {

private float c_qGrade;
private List<QuarterlyGrade_Config> TransGrade;
private List<tracksettingEquiv_Config> equiv;
private List<maxGrade_Config> maxgrade;
private List<batchList_config> studentList;

f_ww_Adapter wwAdapter;
f_pt_Adapter ptAdapter;
f_qe_Adapter qeAdapter;

FragmentPagerAdapter adapterViewPager;

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

    ViewPager vpPager = (ViewPager) findViewById(R.id.vpPager);
    adapterViewPager = new MyPagerAdapter(getSupportFragmentManager());
    vpPager.setAdapter(adapterViewPager);
    vpPager.setCurrentItem(0);

    populateList();
}

private void populateList()
{
    studentList = new ArrayList<>();


    final String loadURL = APP.DOMAIN+"/selectStudents.php";
    RequestQueue reqQueue = Volley.newRequestQueue(classList_index.this);

    StringRequest loadRequest = new StringRequest(Request.Method.POST, loadURL, new Response.Listener<String>() {
        @Override
        public void onResponse(String response){
            try
            {
                JSONObject CLASS_LIST_JSON = new JSONObject(response);
                JSONArray STUDENT_LIST_JARRAY = CLASS_LIST_JSON.getJSONArray("student_list");

                for(int students = 0; students < STUDENT_LIST_JARRAY.length(); students++)
                {
                    JSONObject p_JSONObject = STUDENT_LIST_JARRAY.getJSONObject(students);

                    final String p_studentID    = p_JSONObject.getString("USERID");
                    final String p_lastName  = p_JSONObject.getString("LASTNAME");
                    final String p_firstName  = p_JSONObject.getString("FIRSTNAME");
                    final String p_middleName  = p_JSONObject.getString("MIDDLENAME");
                    final String p_gender  = p_JSONObject.getString("GENDER");
                    final String p_ww1  = p_JSONObject.getString("WW1");
                    final String p_ww2  = p_JSONObject.getString("WW2");
                    final String p_ww3  = p_JSONObject.getString("WW3");
                    final String p_ww4  = p_JSONObject.getString("WW4");
                    final String p_ww5  = p_JSONObject.getString("WW5");
                    final String p_ww6  = p_JSONObject.getString("WW6");
                    final String p_ww7  = p_JSONObject.getString("WW7");
                    final String p_ww8  = p_JSONObject.getString("WW8");
                    final String p_ww9  = p_JSONObject.getString("WW9");
                    final String p_ww10  = p_JSONObject.getString("WW10");
                    final String p_pt1  = p_JSONObject.getString("PT1");
                    final String p_pt2  = p_JSONObject.getString("PT2");
                    final String p_pt3  = p_JSONObject.getString("PT3");
                    final String p_pt4  = p_JSONObject.getString("PT4");
                    final String p_pt5  = p_JSONObject.getString("PT5");
                    final String p_pt6  = p_JSONObject.getString("PT6");
                    final String p_pt7  = p_JSONObject.getString("PT7");
                    final String p_pt8  = p_JSONObject.getString("PT8");
                    final String p_pt9  = p_JSONObject.getString("PT9");
                    final String p_pt10  = p_JSONObject.getString("PT10");
                    final String p_qe  = p_JSONObject.getString("QE1");

                    batchList_config studentConfig = new batchList_config(p_studentID,p_firstName,p_lastName,p_middleName,p_gender,p_ww1,p_ww2,p_ww3,p_ww4,p_ww5,p_ww6,p_ww7,p_ww8,p_ww9,p_ww10,p_pt1,p_pt2,p_pt3,p_pt4,p_pt5,p_pt6,p_pt7,p_pt8,p_pt9,p_pt10,p_qe);
                    studentList.add(studentConfig);
                }
                wwAdapter = new f_ww_Adapter(classList_index.this, studentList);
                ptAdapter = new f_pt_Adapter(classList_index.this, studentList);
                qeAdapter = new f_qe_Adapter(classList_index.this, studentList);


                //where the adapter of recycler views should all be set 
            }
            catch (JSONException e) {
                volleyErrorClass.catchInvalidResponse(e.toString(), classList_index.this);
            }
        }
    }, new Response.ErrorListener() {
        @Override
        public void onErrorResponse(VolleyError error) {
            volleyErrorClass.catchError(error, classList_index.this);
            error.printStackTrace();
        }
    });

    reqQueue.add(loadRequest);

}

public static class MyPagerAdapter extends FragmentPagerAdapter
{
    private static int NUM_ITEMS = 3;

    public MyPagerAdapter(FragmentManager fragmentManager) {
        super(fragmentManager);
    }

    // Returns total number of pages
    @Override
    public int getCount() {
        return NUM_ITEMS;
    }

    // Returns the fragment to display for that page
    @Override
    public Fragment getItem(int position) {
        switch (position) {
            case 0: 
                return f_wworks.newInstance();
            case 1:
                return f_ptasks.newInstance();
            case 2:
                return f_qexams.newInstance();
            default:
                return null;
        }
    }

    // Returns the page title for the top indicator
    @Override
    public CharSequence getPageTitle(int position) {
        switch (position)
        {
            case 0:
                return "Written\nWorks";
            case 1:
                return "Performance\nTasks";
            case 2:
                return "Quarterly\nAssessment";
            default:
                return null;
        }
    }

}

片段示例

public class f_wworks extends Fragment {

private static RecyclerView rv_ww;

private OnFragmentInteractionListener mListener;

public f_wworks() {
}

public static f_wworks newInstance() {
    f_wworks fragment = new f_wworks();

    return fragment;
}

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    // Inflate the layout for this fragment
    View holder = inflater.inflate(R.layout.fragment_wworks, container, false);

    rv_ww = (RecyclerView) holder.findViewById(R.id.rv_wworks);
    rv_ww.setLayoutManager(new LinearLayoutManager(getActivity()));
    rv_ww.setHasFixedSize(true);



    return holder;
}

// TODO: Rename method, update argument and hook method into UI event
public void onButtonPressed(Uri uri) {
    if (mListener != null) {
        mListener.onFragmentInteraction(uri);
    }
}

@Override
public void onAttach(Context context) {
    super.onAttach(context);
    if (context instanceof OnFragmentInteractionListener) {
        mListener = (OnFragmentInteractionListener) context;
    //} else {
      //  throw new RuntimeException(context.toString()
        //        + " must implement OnFragmentInteractionListener");
    }
}

@Override
public void onDetach() {
    super.onDetach();
    mListener = null;
}

public interface OnFragmentInteractionListener {
    // TODO: Update argument type and name
    void onFragmentInteraction(Uri uri);
}

Answer 1

您可以使用Main的fragment实例，并使用它在Fragment中的Fragment调用公共方法来执行此操作

主要

//declare globally

    f_wworks fw;
    f_ptasks fp;
    f_qexams fq;

     @Override
        public Fragment getItem(int position) {
            switch (position) {
                case 0: 
                    fw = f_wworks.newInstance();
                    return fw;
                case 1:
                    fp = f_ptasks.newInstance();
                    return fp;
                case 2:
                    fq = f_qexams.newInstance();
                    return  fq;
                default:
                    return null;
            }
        }

private void populateList()
{
//Once you created adapter
   fw.setDataToAdapter(wwAdapter); //do this to other fragments
}

现在在你的碎片

f_wworks

public class f_wworks extends Fragment {

private RecyclerView rv_ww;

public void setDataToAdapter(f_ww_Adapter fwa){
   rv_ww.setLayoutManager(new LinearLayoutManager());
   rv_ww.setAdapter(fwa);
}

//all other stuff
}