问题
I have data from Firebase data like below:
My problem is my RecyclerView display not as expected. The data of my messages were accumulated, it should go one part by one part and should not be accumulated. I do not know how to explain properly since it has so much codes.
My current output shown as below:
Ask Teacher List Page:
package xxx.xxx.my.package
import android.content.DialogInterface;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Build;
import android.os.Bundle;
import android.support.design.widget.BottomSheetBehavior;
import android.support.design.widget.BottomSheetDialog;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.DefaultItemAnimator;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.view.WindowManager;
import android.widget.RelativeLayout;
import android.widget.TextView;
import android.widget.Toast;
import com.balysv.materialripple.MaterialRippleLayout;
import com.github.florent37.fiftyshadesof.FiftyShadesOf;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.ValueEventListener;
import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.material.components.R;
import com.material.components.activity.lesson.LessonActivity;
import com.material.components.adapter.AdapterAskTeacherList;
import com.material.components.adapter.AdapterQuestionToTeacher;
import com.material.components.model.AskTeacherInfo;
import com.material.components.model.AskTeacherItems;
import com.material.components.model.Chapter;
import com.material.components.model.QuestionsToTeacher;
import com.material.components.model.SubChapter;
import com.material.components.model.Subject;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
public class AskTeacherList extends AppCompatActivity {
private List<AskTeacherItems> askTeacherItemsList = new ArrayList<>();
private AdapterAskTeacherList adapterAskTeacherList;
private RecyclerView askTeacherListRecyclerView;
private RecyclerView recyclerViewQuestions;
private SharedPreferences eduYearSharedPreferences;
private FiftyShadesOf fiftyShadesOf;
private RelativeLayout layout1;
private SharedPreferences analysisSharedPreferences;
private SharedPreferences.Editor editorAnalysisPreferences;
public ArrayList<QuestionsToTeacher> questionsToTeacherList = new ArrayList<>();
private AdapterQuestionToTeacher adapterQuestionToTeacher;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_ask_teacher_list);
Toolbar toolbar = findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
getSupportActionBar().setHomeButtonEnabled(true);
analysisSharedPreferences = getApplicationContext().getSharedPreferences("AnalysisSharedPreferences",MODE_PRIVATE);
editorAnalysisPreferences = analysisSharedPreferences.edit();
adapterAskTeacherList = new AdapterAskTeacherList(askTeacherItemsList, questionsToTeacherList, getApplicationContext());
askTeacherListRecyclerView = findViewById(R.id.askTeacherListRecyclerView);
layout1 = findViewById(R.id.layout1);
fiftyShadesOf = FiftyShadesOf.with(this).on(R.id.layout1).start();
fiftyShadesOf.start();
askTeacherListRecyclerView.setHasFixedSize(true);
askTeacherListRecyclerView.setNestedScrollingEnabled(false);
RecyclerView.LayoutManager layoutManager = new LinearLayoutManager(getApplicationContext());
askTeacherListRecyclerView.setLayoutManager(layoutManager);
askTeacherListRecyclerView.setItemAnimator(new DefaultItemAnimator());
askTeacherListRecyclerView.setAdapter(adapterAskTeacherList);
adapterAskTeacherList.setOnClickListener(new AdapterAskTeacherList.OnClickListener() {
@Override
public void onItemClick(View view, AskTeacherItems obj, int pos) {
/*
Intent gotoLesson = new Intent(AskTeacherList.this, LessonActivity.class);
gotoLesson.putExtra("subchapter_id",obj.subChapterId);
gotoLesson.putExtra("subChapterTitle",obj.subChapterTitle);
editorAnalysisPreferences.putString("subchapterId",obj.subChapterId);
editorAnalysisPreferences.commit();
startActivity(gotoLesson);
*/
}
@Override
public void onItemLongClick(View view, AskTeacherItems obj, int pos) {
}
});
displayAskTeacherItems();
/*
adapterQuestionToTeacher = new AdapterQuestionToTeacher(questionsToTeacherList);
recyclerViewQuestions = findViewById(R.id.recyclerViewQuestions);
LinearLayoutManager linearLayoutManager = new LinearLayoutManager(getApplicationContext(),LinearLayoutManager.VERTICAL,false);
recyclerViewQuestions.setLayoutManager(linearLayoutManager);
recyclerViewQuestions.setHasFixedSize(true);
recyclerViewQuestions.setNestedScrollingEnabled(false);
recyclerViewQuestions.setAdapter(adapterQuestionToTeacher);*/
eduYearSharedPreferences = getApplicationContext().getSharedPreferences("EduYearPreferences", MODE_PRIVATE);
showAdminMessage();
}
private BottomSheetBehavior mBehavior;
private BottomSheetDialog mBottomSheetDialog;
private View bottom_sheet;
private void showAdminMessage()
{
bottom_sheet = findViewById(R.id.bottom_sheet_admin_message);
mBehavior = BottomSheetBehavior.from(bottom_sheet);
if (mBehavior.getState() == BottomSheetBehavior.STATE_EXPANDED) {
mBehavior.setState(BottomSheetBehavior.STATE_COLLAPSED);
}
final View view = getLayoutInflater().inflate(R.layout.sheet_basic, null);
((TextView) view.findViewById(R.id.name)).setText("Test Name");
((TextView) view.findViewById(R.id.address)).setText(R.string.middle_lorem_ipsum);
(view.findViewById(R.id.bt_close)).setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
mBottomSheetDialog.dismiss();
}
});
(view.findViewById(R.id.bt_details)).setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Toast.makeText(getApplicationContext(), "Details clicked", Toast.LENGTH_SHORT).show();
}
});
mBottomSheetDialog = new BottomSheetDialog(this);
mBottomSheetDialog.setContentView(view);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
mBottomSheetDialog.getWindow().addFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
}
mBottomSheetDialog.show();
mBottomSheetDialog.setOnDismissListener(new DialogInterface.OnDismissListener() {
@Override
public void onDismiss(DialogInterface dialog) {
mBottomSheetDialog = null;
}
});
}
private SubChapter subChapter;
private HashMap<String,String> dataAskTeacher = new HashMap<>();
private void displayAskTeacherItems()
{
askTeacherItemsList.clear();
FirebaseAuth firebaseAuth = FirebaseAuth.getInstance();
String uuid = firebaseAuth.getUid();
GsonBuilder builder = new GsonBuilder();
final Gson gson = builder.create();
FirebaseDatabase.getInstance().getReference().child("ask_teachers/students/"+uuid+"/subjects")
.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
for(DataSnapshot snapshot: dataSnapshot.getChildren())
{
final String subjectId = snapshot.getKey();
System.out.println("ssss--subject_id:-"+subjectId);
String eduYearId = eduYearSharedPreferences.getString("eduYearValue","");
//Chapters label
for(DataSnapshot chapterLabel: snapshot.getChildren()){
//Chapter data
for(DataSnapshot chapterData: chapterLabel.getChildren())
{
final String chapterId = chapterData.getKey();
System.out.println("ssss--chapter_id:-"+chapterId);
//Subchapter label
for(DataSnapshot subChapterLabel: chapterData.getChildren())
{
//Subchapter Data
for(DataSnapshot subChapterData: subChapterLabel.getChildren())
{
final String subchapterId = subChapterData.getKey();
FirebaseDatabase.getInstance().getReference().child("subjects/"+eduYearId+"/data_subject/"+subjectId)
.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSubjectSnapshot) {
String subjectReceived = gson.toJson(dataSubjectSnapshot.getValue());
if(!subjectReceived.equals("null"))
{
Subject subject = gson.fromJson(subjectReceived,Subject.class);
dataAskTeacher.put("subject_title",subject.subjectName);
}
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});
FirebaseDatabase.getInstance().getReference().child("chapters/"+subjectId+"/chapters/"+chapterId)
.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataChapterSnapshot) {
String chaptersReceived = gson.toJson(dataChapterSnapshot.getValue());
if(!chaptersReceived.equals("null"))
{
System.out.println(chaptersReceived);
Chapter chapter = gson.fromJson(chaptersReceived,Chapter.class);
System.out.println("chapters---------");
System.out.println(chapter.chapterTitle);
dataAskTeacher.put("chapter_title",chapter.chapterTitle);
}
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});
FirebaseDatabase.getInstance().getReference().child("subchapters/"+chapterId+"/subchapters_data/"+subchapterId)
.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSubChapterSnapshot) {
String dataSubChaptersReceived = gson.toJson(dataSubChapterSnapshot.getValue());
if(!dataSubChaptersReceived.equals("null"))
{
fiftyShadesOf.stop();
layout1.setVisibility(View.GONE);
System.out.println("data subchapters----------------------");
System.out.println(dataSubChaptersReceived);
subChapter = gson.fromJson(dataSubChaptersReceived,SubChapter.class);
dataAskTeacher.put("subchapter_title",subChapter.subchapterTitle);
dataAskTeacher.put("subchapter_id",subChapter.subchapterId);
System.out.println("subbbbb----"+subChapter.subchapterId);
String dataAskTeacherReceived = gson.toJson(dataAskTeacher);
AskTeacherItems askTeacherItems = gson.fromJson(dataAskTeacherReceived,AskTeacherItems.class);
askTeacherItemsList.add(askTeacherItems);
adapterAskTeacherList.notifyDataSetChanged();
}
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});
//Messages Label
System.out.println("subjechapterId...."+subchapterId);
for(DataSnapshot messagesLabel: subChapterData.getChildren())
{
//Messages Data
for(DataSnapshot messagesData: messagesLabel.getChildren())
{
String messageQuestion = gson.toJson(messagesData.getValue());
QuestionsToTeacher questionsToTeacher = gson.fromJson(messageQuestion,QuestionsToTeacher.class);
//Problem start here
questionsToTeacherList.add(questionsToTeacher);
System.out.println(questionsToTeacher.messages+" "+questionsToTeacher.questionStatus);
}
}
}
}
}
}
}
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
@Override
public boolean onSupportNavigateUp() {
onBackPressed();
return true;
}
}
Adapter Ask Teacher List
package xxx.xxx.my.package
import android.content.Context;
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.RelativeLayout;
import android.widget.TextView;
import com.material.components.R;
import com.material.components.activity.askteachers.AskTeacherList;
import com.material.components.model.AskTeacherInfo;
import com.material.components.model.AskTeacherItems;
import com.material.components.model.QuestionsToTeacher;
import java.util.ArrayList;
import java.util.List;
public class AdapterAskTeacherList extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
private List<AskTeacherItems> askTeacherListItems = new ArrayList<>();
private OnClickListener onClickListener = null;
private List<QuestionsToTeacher> questionsToTeacherList = new ArrayList<>();
private Context context;
public AdapterAskTeacherList(List<AskTeacherItems> askTeacherListItems, List<QuestionsToTeacher> questionsToTeacherList, Context context) {
this.askTeacherListItems = askTeacherListItems;
this.questionsToTeacherList = questionsToTeacherList;
this.context = context;
}
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
RecyclerView.ViewHolder vh;
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_ask_teacher_list,parent,false);
vh = new OriginalViewHolder(v);
return vh;
}
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, final int position) {
if(holder instanceof OriginalViewHolder)
{
OriginalViewHolder view = (OriginalViewHolder) holder;
final AskTeacherItems askTeacherItems = askTeacherListItems.get(position);
view.askTeacherStatus.setText(askTeacherItems.askTeacherStatus);
view.dtCreated.setText(askTeacherItems.dtCreated);
view.subjectTitle.setText(askTeacherItems.subjectTitle);
view.chapterTitle.setText(askTeacherItems.chapterTitle);
view.subchapter.setText(askTeacherItems.subChapterTitle);
view.lyt_parent_ask_teacher_list.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if(onClickListener == null) return;
onClickListener.onItemClick(v,askTeacherItems,position);
}
});
view.lyt_parent_ask_teacher_list.setOnLongClickListener(new View.OnLongClickListener() {
@Override
public boolean onLongClick(View v) {
if (onClickListener == null) return false;
onClickListener.onItemLongClick(v, askTeacherItems, position);
return true;
}
});
LinearLayoutManager linearLayoutManager = new LinearLayoutManager(context,LinearLayoutManager.VERTICAL,false);
view.recyclerView.setLayoutManager(linearLayoutManager);
view.recyclerView.setHasFixedSize(true);
view.recyclerView.setNestedScrollingEnabled(false);
AdapterQuestionToTeacher adapterQuestionToTeacher = new AdapterQuestionToTeacher(questionsToTeacherList);
view.recyclerView.setAdapter(adapterQuestionToTeacher);
}
}
public class OriginalViewHolder extends RecyclerView.ViewHolder{
public View lyt_parent_ask_teacher_list;
public TextView subjectTitle, chapterTitle,subchapter,askTeacherStatus,dtCreated;
public RelativeLayout lyt_checked, lyt_image;
public RecyclerView recyclerView;
public OriginalViewHolder(View itemView) {
super(itemView);
lyt_parent_ask_teacher_list = itemView.findViewById(R.id.lyt_parent_ask_teacher_list);
subjectTitle = itemView.findViewById(R.id.subjectTitle);
chapterTitle = itemView.findViewById(R.id.chapterTitle);
subchapter = itemView.findViewById(R.id.subchapter);
askTeacherStatus = itemView.findViewById(R.id.askTeacherStatus);
dtCreated = itemView.findViewById(R.id.dtCreated);
lyt_checked = itemView.findViewById(R.id.lyt_checked);
lyt_image = itemView.findViewById(R.id.lyt_image);
recyclerView = itemView.findViewById(R.id.recyclerViewQuestions);
}
}
@Override
public int getItemCount() {
return askTeacherListItems.size();
}
public void setOnClickListener(OnClickListener onClickListener) {
this.onClickListener = onClickListener;
}
public interface OnClickListener {
void onItemClick(View view, AskTeacherItems obj, int pos);
void onItemLongClick(View view, AskTeacherItems obj, int pos);
}
}
AdapterQuestionToTeacher
package xxx.xxx.my.package;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import com.material.components.R;
import com.material.components.model.QuestionsToTeacher;
import java.util.ArrayList;
import java.util.List;
public class AdapterQuestionToTeacher extends RecyclerView.Adapter<RecyclerView.ViewHolder>{
private List<QuestionsToTeacher> questionsToTeacherList = new ArrayList<>();
public AdapterQuestionToTeacher(List<QuestionsToTeacher> questionsToTeacherList) {
this.questionsToTeacherList = questionsToTeacherList;
}
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
RecyclerView.ViewHolder vh;
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_ask_teacher_question,parent,false);
vh = new OriginalViewHolder(v);
return vh;
}
public class OriginalViewHolder extends RecyclerView.ViewHolder{
public TextView questionStatus,messages;
public OriginalViewHolder(View itemView) {
super(itemView);
questionStatus = itemView.findViewById(R.id.questionStatus);
messages = itemView.findViewById(R.id.messages);
}
}
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
if(holder instanceof OriginalViewHolder)
{
OriginalViewHolder view = (OriginalViewHolder) holder;
final QuestionsToTeacher questionsToTeacher = questionsToTeacherList.get(position);
view.questionStatus.setText(questionsToTeacher.questionStatus);
view.messages.setText(questionsToTeacher.messages);
}
}
@Override
public int getItemCount() {
return questionsToTeacherList.size();
}
}
content_ask_teacher_list.xml
<include android:id="@+id/layout1" layout="@layout/item_ask_teacher_list" />
<android.support.v7.widget.RecyclerView
android:id="@+id/askTeacherListRecyclerView"
android:layout_width="match_parent"
android:layout_height="wrap_content">
</android.support.v7.widget.RecyclerView>
item_ask_teacher_list.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/lyt_parent_ask_teacher_list"
style="@style/RippleStyleBlack"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@android:drawable/dialog_holo_light_frame"
android:padding="4dp">
<android.support.v7.widget.CardView
android:layout_width="match_parent"
android:layout_height="wrap_content">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:paddingBottom="10dp"
android:orientation="vertical">
<android.support.v7.widget.RecyclerView
android:id="@+id/recyclerViewQuestions"
android:layout_below="@id/dottedHorizontalRule"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</RelativeLayout>
</android.support.v7.widget.CardView>
</RelativeLayout>
</RelativeLayout>
回答1:
It's hard to point at one specific place and say "this is the issue," since there's a lot of code. But it boils down to the fact that there's only a single List<QuestionsToTeacher> questionsToTeacherList inside AdapterAskTeacherList.
Instead, you should have a List<List<QuestionsToTeacher>>. That is, a list of lists.
To accomplish this, you'll have to change both the Activity and the outer Adapter. In the activity, change this:
public ArrayList<QuestionsToTeacher> questionsToTeacherList = new ArrayList<>();
...
for(DataSnapshot messagesLabel: subChapterData.getChildren())
{
//Messages Data
for(DataSnapshot messagesData: messagesLabel.getChildren())
{
String messageQuestion = gson.toJson(messagesData.getValue());
QuestionsToTeacher questionsToTeacher = gson.fromJson(messageQuestion,QuestionsToTeacher.class);
//Problem start here
questionsToTeacherList.add(questionsToTeacher);
System.out.println(questionsToTeacher.messages+" "+questionsToTeacher.questionStatus);
}
}
to this:
public ArrayList<ArrayList<QuestionsToTeacher>> questionsToTeacherList = new ArrayList<>();
...
for(DataSnapshot messagesLabel: subChapterData.getChildren())
{
ArrayList<QuestionsToTeacher> sublist = new ArrayList<>();
//Messages Data
for(DataSnapshot messagesData: messagesLabel.getChildren())
{
String messageQuestion = gson.toJson(messagesData.getValue());
QuestionsToTeacher questionsToTeacher = gson.fromJson(messageQuestion,QuestionsToTeacher.class);
//Problem start here
sublist.add(questionsToTeacher);
System.out.println(questionsToTeacher.messages+" "+questionsToTeacher.questionStatus);
}
questionsToTeacherList.add(sublist);
}
What you're doing here is taking the ArrayList<QuestionsToTeacher> (the list of questions) and changing it to an ArrayList<ArrayList<QuestionsToTeacher>> (a list of lists of questions). And then, as you read the data out of the database, you create multiple ArrayList<QuestionsToTeacher> and add them to the list of lists.
Then, in your adapter, change this:
private List<QuestionsToTeacher> questionsToTeacherList = new ArrayList<>();
public AdapterAskTeacherList(List<AskTeacherItems> askTeacherListItems, List<QuestionsToTeacher> questionsToTeacherList, Context context) {
...
this.questionsToTeacherList = questionsToTeacherList;
...
}
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, final int position) {
...
AdapterQuestionToTeacher adapterQuestionToTeacher = new AdapterQuestionToTeacher(questionsToTeacherList);
view.recyclerView.setAdapter(adapterQuestionToTeacher);
...
}
to this:
private ArrayList<ArrayList<QuestionsToTeacher>> questionsToTeacherList = new ArrayList<>();
public AdapterAskTeacherList(List<AskTeacherItems> askTeacherListItems, ArrayList<ArrayList<QuestionsToTeacher>> questionsToTeacherList, Context context) {
this.questionsToTeacherList = questionsToTeacherList;
...
}
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, final int position) {
...
List<QuestionsToTeacher> sublist = questionsToTeacherList.get(position);
AdapterQuestionToTeacher adapterQuestionToTeacher = new AdapterQuestionToTeacher(sublist);
view.recyclerView.setAdapter(adapterQuestionToTeacher);
...
}
Again, you're changing the adapter to accept a list of lists of questions (instead of just a list of questions). The key is that you then pass only a single list of questions to each nested RecyclerView.
来源：https://stackoverflow.com/questions/48638244/problems-with-nested-recylerview