Pourquoi l'oncreateview du fragment actuel est-il appelé en appuyant sur le bouton de retour?

Question

J'essaie de récupérer le fragment du backstack. Il est récupéré mais le problème est qu'en appuyant sur le bouton de retour, la vue oncreate et les méthodes de vie suivantes du fragment courant sont également appelées. Voici mon code pour mettre le fragment dans le backstack:

fragment=new FileTrackingFragment(); 
bundle=new Bundle(); 
bundle.putString("name","Dak Monitoring"); 
bundle.putInt("num",2); 
fragment.setArguments(bundle); 
ft.replace(R.id.parent, fragment, fragment.getClass().getName()); 
ft.addToBackStack(fragment.getClass().getName()); 
ft.commit(); 
break; 

est ici le code du fragment:

package com.example.rajvirsingh.epunjaboffice.DakMonitoring; 

import android.app.Activity; 
import android.app.ProgressDialog; 
import android.os.Bundle; 
import android.support.annotation.Nullable; 
import android.support.design.widget.Snackbar; 
import android.support.percent.PercentRelativeLayout; 
import android.support.v4.app.Fragment; 
import android.support.v7.app.AppCompatActivity; 
import android.support.v7.widget.LinearLayoutManager; 
import android.support.v7.widget.RecyclerView; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.ViewGroup; 
import android.widget.AdapterView; 
import android.widget.ArrayAdapter; 
import android.widget.Spinner; 
import android.widget.TextView; 
import android.widget.Toast; 

import com.example.rajvirsingh.epunjaboffice.FileTracking.HistoryAdapter; 
import com.example.rajvirsingh.epunjaboffice.MainActivity; 
import com.example.rajvirsingh.epunjaboffice.R; 
import com.example.rajvirsingh.epunjaboffice.Utility.Constants; 
import com.example.rajvirsingh.epunjaboffice.Utility.SessionManager; 
import com.loopj.android.http.AsyncHttpClient; 
import com.loopj.android.http.RequestParams; 
import com.loopj.android.http.TextHttpResponseHandler; 

import org.json.JSONArray; 

import java.util.ArrayList; 

import cz.msebera.android.httpclient.Header; 

/** 
* Created by rajvirsingh on 07/03/17. 
*/ 

public class ConsolidatedReportFragment extends Fragment implements AdapterView.OnItemSelectedListener { 
    SessionManager sessionManager; 
    JSONArray consolidatedRJsonArray; 
    String userCode,branchCode; 
    MainActivity mainActivity; 
    Spinner spinDuration; 
    String selectedDuration=""; 
    ProgressDialog pDialog; 
    TextView error,serial; 
    PercentRelativeLayout pl; 
    PercentRelativeLayout ll; 
    RecyclerView recyclerView; 
    AsyncHttpClient client = new AsyncHttpClient(); 
    String []durationValues={"This Week","This Month","This Year","Total"}; 


    @Nullable 
    @Override 
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) { 
    return inflater.inflate(R.layout.fragment_dak_monitoring_consolidated,container,false); 
    } 


    @Override 
    public void onAttach(Activity activity) { 
    super.onAttach(activity); 
    sessionManager=SessionManager.NewInstance(activity); 
    userCode=sessionManager.pref.getString("usercode",""); 
    branchCode=sessionManager.pref.getString("branchcode",""); 
    mainActivity=(MainActivity) getActivity(); 
    if(((AppCompatActivity) getActivity()).getSupportActionBar()!=null) { 
     ((AppCompatActivity) getActivity()).getSupportActionBar().show(); 
     mainActivity.setToolbarTitle("Consolidated Report"); 
     mainActivity.unlockDrawer(); 
     mainActivity.loadNavigationMenu(R.menu.menu_dak_monitoring); 
    } 
    } 

    @Override 
    public void onViewCreated(View view, @Nullable Bundle savedInstanceState) { 
    super.onViewCreated(view, savedInstanceState); 

    pDialog = new ProgressDialog(getActivity(),R.style.DialogStyle); 
    pDialog.setMessage("Loading..."); 
    pDialog.setTitle("Office Management"); 
    pDialog.setIndeterminate(true); 
    pDialog.setCancelable(true); 

    sessionManager=SessionManager.NewInstance(getActivity()); 

    error=(TextView)view.findViewById(R.id.err); 
    serial=(TextView)view.findViewById(R.id.serial); 


    spinDuration=(Spinner)view.findViewById(R.id.spin_duration); 
    ArrayAdapter<String> arrayAdapter=new ArrayAdapter<String>(getActivity(),android.R.layout.simple_spinner_item,durationValues); 
    arrayAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item); 
    spinDuration.setAdapter(arrayAdapter); 
    spinDuration.setOnItemSelectedListener(this); 
    spinDuration.setSelection(0); 
    selectedDuration="1"; 

    pl=(PercentRelativeLayout)view.findViewById(R.id.percentile); 

    ll=(PercentRelativeLayout) view.findViewById(R.id.ll1); 
    recyclerView=(RecyclerView)view.findViewById(R.id.recyclerView); 

    if(Constants.isOnline(getActivity())) 
    { 

     getConsolidatedReport(); 
    } 
    } 

    void getConsolidatedReport() 
    { 
    RequestParams params = new RequestParams(); 
    params.put("_userMasterCode",userCode); 
    params.put("_parameter", selectedDuration); 
    String url=getString(R.string.urlGetConsolidatedMonitoringReport); 

    client.get(url, params, new TextHttpResponseHandler() { 
     @Override 
     public void onFailure(int statusCode, Header[] headers, String responseString, Throwable throwable) { 
     pDialog.dismiss(); 
     ll.setVisibility(View.GONE); 
     recyclerView.setVisibility(View.GONE); 
     error.setVisibility(View.VISIBLE); 
     if(getView()!=null) 
      Snackbar.make(getView(), "Error!", Snackbar.LENGTH_LONG).show(); 
     } 

     @Override 
     public void onSuccess(int statusCode, Header[] headers, String responseString) { 

     try { 
      pDialog.dismiss(); 
      int p1 = responseString.indexOf(">"); 
      int p2 = responseString.lastIndexOf("<"); 
      String r = responseString.substring(p1 + 1, p2); 
      p1 = r.indexOf(">"); 
      r = r.substring(p1 + 1, r.length()); 
      ll.setVisibility(View.VISIBLE); 
      recyclerView.setVisibility(View.VISIBLE); 
      error.setVisibility(View.GONE); 
      consolidatedRJsonArray = new JSONArray(r); 
      ConsolidatedReportAdapter consolidatedReportAdapter=new ConsolidatedReportAdapter(consolidatedRJsonArray,getActivity()); 
      recyclerView.setAdapter(consolidatedReportAdapter); 
      recyclerView.setLayoutManager(new LinearLayoutManager(getActivity())); 
     } catch (Exception e) { 
      if (getActivity() != null && isAdded()) { 
      ll.setVisibility(View.GONE); 
      recyclerView.setVisibility(View.GONE); 
      error.setVisibility(View.VISIBLE); 
      if(getView()!=null) 
       Snackbar.make(getView(), "No Information Exist! For Selection", Snackbar.LENGTH_LONG).show(); 
      else 
       Toast.makeText(getActivity(),"No Information Exist! For Selection",Toast.LENGTH_LONG).show(); 
      pDialog.dismiss(); 
      } 
     } 
     } 
    }); 
    } 

    @Override 
    public void onItemSelected(AdapterView<?> parent, View view, int position, long id) { 
    switch (parent.getId()) 
    { 
     case R.id.spin_duration: 
     selectedDuration=String.valueOf(position+1); 
     getConsolidatedReport(); 
     break; 
    } 
    } 

    @Override 
    public void onNothingSelected(AdapterView<?> parent) { 

    } 

    @Override 
    public void onPause() { 
    super.onPause(); 
    pDialog.dismiss(); 
    } 

    @Override 
    public void onStop() { 
    client.cancelAllRequests(true); 
    super.onStop(); 
    } 

} 

Answer 1

Il sera va appeler en tant que votre vue est détruite lorsque vous passez au fragment suivant il faudra donc à nouveau afficher la vue en appuyant sur le bouton de retour et cela devrait être l'approche car garder la vue des fragments (qui ne sont pas visibles actuellement) en mémoire provoquera un problème de mémoire plus tard. C'est la méthode onCreate() qui ne va plus appeler.

Si vous ne voulez pas appeler onCreateView sur la presse à l'époque utilisez ft.add(R.id.parent, fragment, fragment.getClass().getName());

Pour plus de détails sur la façon dont se comportent de la pile fragment s'il vous plaît se référer here.