Develop Reference

how to get data from mysql database into recycler view?

I am making an app that let users create meetings and I would like the details of the meeting (eg name, type, location) in a recycler view.I ran the php code by itself and was able to get the values from the database.
Currently, I am getting an error of
java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setText(java.lang.CharSequence)' on a null object reference
at in recyclerviewAdapter
holder.Name.setText(users.getName());
holder.Type.setText(users.getType());
holder.Location.setText(users.getLocation());
which is linked to
public class Users {
private String name,type,location;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getType() {
return type;
}
public void setType(String type) {
this.type = type;
}
public String getLocation() {
return location;
}
public void setLocation(String location) {
this.location = location;
}
}
recyclerviewAdapter
public class UserAdapter extends RecyclerView.Adapter<UserAdapter.UserHolder>{
Context context;
List<Users> usersList;
public UserAdapter(Context context, List<Users> usersList) {
this.context = context;
this.usersList = usersList;
}
#NonNull
#Override
public UserHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View userLayout= LayoutInflater.from(parent.getContext()).inflate(R.layout.activity_main2,parent,false);
return new UserHolder(userLayout);
}
#Override
public void onBindViewHolder(#NonNull UserHolder holder, int position) {
Users users=usersList.get(position);
holder.Name.setText(users.getName());
holder.Type.setText(users.getType());
holder.Location.setText(users.getLocation());
}
#Override
public int getItemCount() {
return usersList.size();
}
public class UserHolder extends RecyclerView.ViewHolder{
TextView Name,Type,Location;
public UserHolder(#NonNull View itemView){
super(itemView);
Name=itemView.findViewById(R.id.textTitle);
Type=itemView.findViewById(R.id.textType);
Location=itemView.findViewById(R.id.textLocation);
}
}
}
main activity code
public class MainActivity2 extends AppCompatActivity {
private static final String URL = "http://10.0.2.2/mad/activitydisplay.php";
RecyclerView recyclerView;
UserAdapter userAdapter;
List<Users> usersList;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main2);
recyclerView = findViewById(R.id.recylcerList);
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(new LinearLayoutManager(this));
usersList=new ArrayList<>();
LoadAllUser();
}
private void LoadAllUser() {
JsonArrayRequest request =new JsonArrayRequest(URL, new Response.Listener<JSONArray>() {
#Override
public void onResponse(JSONArray array) {
for (int i=0;i<array.length();i++){
try {
JSONObject object=array.getJSONObject(i);
String name=object.getString("eventname").trim();
String type=object.getString("type").trim();
String location=object.getString("location").trim();
Users user= new Users();
user.setName(name);
user.setType(type);
user.setLocation(location);
usersList.add(user);
} catch (JSONException e) {
e.printStackTrace();
}
}
userAdapter=new UserAdapter(MainActivity2.this,usersList);
recyclerView.setAdapter(userAdapter);
}
},new Response.ErrorListener(){
#Override
public void onErrorResponse(VolleyError error){
Toast.makeText(MainActivity2.this, error.toString(), Toast.LENGTH_SHORT).show();
}
});
RequestQueue requestQueue=Volley.newRequestQueue(MainActivity2.this);
requestQueue.add((request));
}
}
php code to get data from table
$sql="SELECT * FROM `activitytable` ";
$result=mysqli_query($conn,$sql);
$user=array();
while($row = mysqli_fetch_assoc($result)){
$index['eventname']=$row['eventname'];
$index['type']=$row['type'];
$index['location']=$row['location'];
array_push($user, $index);
}
echo json_encode($user);
activity_main2.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity2">
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/recylcerList"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</LinearLayout>
activity_list resource file
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<androidx.cardview.widget.CardView
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="16dp"
android:orientation="vertical">
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:orientation="horizontal" >
<TextView
style="bold"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Title:"
android:textColor="#color/black"
android:textSize="24dp" />
<TextView
android:id="#+id/textTitle"
style="bold"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#color/black"
android:textSize="24dp" />
</LinearLayout>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:orientation="horizontal" >
<TextView
style="bold"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Type:"
android:textColor="#color/black"
android:textSize="24dp" />
<TextView
android:id="#+id/textType"
style="bold"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#color/black"
android:textSize="24dp" />
</LinearLayout>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:orientation="horizontal" >
<TextView
style="bold"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Location:"
android:textColor="#color/black"
android:textSize="24dp" />
<TextView
android:id="#+id/textLocation"
style="bold"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#color/black"
android:textSize="24dp" />
</LinearLayout>
</LinearLayout>
</androidx.cardview.widget.CardView>
</LinearLayout>

instead of
public UserHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View userLayout= LayoutInflater.from(parent.getContext()).inflate(R.layout.activity_main2,parent,false);
return new UserHolder(userLayout);
}
use this
public UserHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View userLayout= LayoutInflater.from(parent.getContext()).inflate(R.layout.activity_list ,parent,false);
return new UserHolder(userLayout);
}
because activity_main2 doesn't contain R.id.textTitle,R.id.textType,R.id.textLocation

check your xml(R.layout.activity_main2) looks like id of your view are from another layout

Recycleview doesn't appear in a Fragment

I'm trying to get some data from my firebase, so I created recycleview in activity to get the data, and it worked without problem.
But now, I added my recycle to a Fragment to get data, and it managed to get the data but I can't see it, the firenase (on success) tell me that it work, but I can't see the recycleview.
I searched more and more without finding any solution, there are another one have the same problem, and he didn't find any solution else, here .
RecyclerView doesn't appear in Fragment
I tried all the solution in this question but, it didn't work, now I spent more than two months without finding out the problem.
FriendsFragment
public class FriendsFragment extends Fragment {
DatabaseReference databaseReference;
RecyclerView recyclerView;
RecyclerView.Adapter adapter ;
ProgressDialog progressDialog;
List<ImageUploadInfo> list = new ArrayList<>();
private Context context;
public FriendsFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(com.wanjy.dannie.rivchat.R.layout.fragment_people, container, false);
context = view.getContext();
recyclerView = (RecyclerView) view.findViewById(R.id.recycleListFriend);
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(new LinearLayoutManager(context));
progressDialog = new ProgressDialog(context);
progressDialog.setMessage("Loading Images From Firebase.");
progressDialog.show();
databaseReference = FirebaseDatabase.getInstance().getReference("All_Image_Uploads_Database");
databaseReference.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot snapshot) {
for (DataSnapshot postSnapshot : snapshot.getChildren()) {
ImageUploadInfo imageUploadInfo = postSnapshot.getValue(ImageUploadInfo.class);
list.add(imageUploadInfo);
}
adapter = new RecyclerViewAdapter(context, list);
recyclerView.setAdapter(adapter);
progressDialog.dismiss();
}
#Override
public void onCancelled(DatabaseError databaseError) {
// Hiding the progress dialog.
progressDialog.dismiss();
}
});
return inflater.inflate(R.layout.fragment_people, container, false);
}
}
RecyclerViewAdapter
public class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerViewAdapter.ViewHolder> {
Context context;
List<ImageUploadInfo> MainImageUploadInfoList;
public RecyclerViewAdapter(Context context, List<ImageUploadInfo> TempList) {
this.MainImageUploadInfoList = TempList;
this.context = context;
}
#Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.recyclerview_items, parent, false);
ViewHolder viewHolder = new ViewHolder(view);
return viewHolder;
}
#Override
public void onBindViewHolder(ViewHolder holder, int position) {
ImageUploadInfo UploadInfo = MainImageUploadInfoList.get(position);
holder.imageNameTextView.setText(UploadInfo.getImageName());
//Loading image from Glide library.
Glide.with(context).load(UploadInfo.getImageURL()).into(holder.imageView);
}
#Override
public int getItemCount() {
return MainImageUploadInfoList.size();
}
class ViewHolder extends RecyclerView.ViewHolder {
public ImageView imageView;
public TextView imageNameTextView;
public ViewHolder(View itemView) {
super(itemView);
imageView = (ImageView) itemView.findViewById(R.id.imageView);
imageNameTextView = (TextView) itemView.findViewById(R.id.ImageNameTextView);
}
}
}
ImageUploadInfo
public class ImageUploadInfo {
public String imageName;
public String imageURL;
public ImageUploadInfo() {
}
public ImageUploadInfo(String name, String url) {
this.imageName = name;
this.imageURL= url;
}
public String getImageName() {
return imageName;
}
public String getImageURL() {
return imageURL;
}
}
recyclerview_items
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:card_view="http://schemas.android.com/apk/res-auto"
android:id="#+id/cardview1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
card_view:cardElevation="5dp"
card_view:contentPadding="5dp"
card_view:cardCornerRadius="5dp"
card_view:cardMaxElevation="5dp">
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:background="#FFFFFF"
android:orientation="vertical">
<LinearLayout
android:layout_height="wrap_content"
android:layout_width="match_parent"
android:orientation="horizontal"
android:background="#FFFFFF"
android:padding="1dp">
<ImageView
android:layout_height="50dp"
android:layout_width="50dp"
android:src="#android:drawable/ic_delete"
android:scaleType="fitXY"/>
<LinearLayout
android:layout_height="match_parent"
android:layout_width="wrap_content"
android:orientation="vertical"
android:background="#FFFFFF"
android:layout_weight="1.0"
android:padding="3dp">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="15dp"
android:textColor="#000000"
android:text="أخبار الدولة"
android:gravity="center"
android:id="#+id/myname"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceSmall"
android:text="التاريخ"
android:id="#+id/date"
android:textColor="#000000"/>
</LinearLayout>
</LinearLayout>
<ImageView
android:id="#+id/imageView"
android:layout_width="fill_parent"
android:layout_height="180dp"
android:src="#mipmap/ic_launcher"
android:background="#FFFFFF"/>
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="Large Text"
android:layout_weight="1.0"
android:textSize="14sp"
android:textColor="#000000"
android:layout_gravity="right"
android:padding="4dp"
android:gravity="right"
android:id="#+id/ImageNameTextView"/>
<LinearLayout
android:layout_height="wrap_content"
android:layout_width="match_parent"
android:orientation="horizontal"
android:background="#FFFFFF"
android:padding="2dp">
<LinearLayout
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:orientation="horizontal"
android:background="#FFFFFF"
android:layout_weight="1.0"
android:gravity="center">
<ImageView
android:layout_height="30dp"
android:layout_width="30dp"
android:src="#android:drawable/ic_delete"
android:scaleType="fitXY"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceSmall"
android:text="0"
android:textColor="#000000"
android:padding="2dp"/>
</LinearLayout>
<LinearLayout
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:orientation="horizontal"
android:background="#FFFFFF"
android:layout_weight="1.0"
android:gravity="center">
<ImageView
android:layout_height="30dp"
android:layout_width="30dp"
android:src="#android:drawable/ic_delete"
android:scaleType="fitXY"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceSmall"
android:text="0"
android:textColor="#000000"
android:padding="2dp"/>
</LinearLayout>
<LinearLayout
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:orientation="horizontal"
android:background="#FFFFFF"
android:layout_weight="1.0"
android:gravity="center">
<ImageView
android:layout_height="30dp"
android:layout_width="30dp"
android:src="#android:drawable/ic_delete"
android:scaleType="fitXY"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceSmall"
android:text="0"
android:textColor="#000000"
android:padding="2dp"/>
</LinearLayout>
</LinearLayout>
</LinearLayout>
</android.support.v7.widget.CardView>
fragment_people
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v4.widget.SwipeRefreshLayout
android:id="#+id/swipeRefreshLayout"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v7.widget.RecyclerView
android:id="#+id/recycleListFriend"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginTop="15dp" />
</android.support.v4.widget.SwipeRefreshLayout>
</RelativeLayout>
My build gradle
compile 'com.android.support:appcompat-v7:24.2.1'
compile 'com.android.support:design:24.2.1'
compile 'com.google.firebase:firebase-core:9.8.0'
compile 'com.google.firebase:firebase-database:9.8.0'
compile 'com.google.firebase:firebase-auth:9.8.0'
testCompile 'junit:junit:4.12'
compile 'de.hdodenhof:circleimageview:2.1.0'
compile 'com.yarolegovich:lovely-dialog:1.0.4'
compile 'com.android.support:cardview-v7:25.0.1'
compile 'com.android.support:percent:25.0.1'
compile 'com.github.bumptech.glide:glide:3.7.0'
Note My recycle work in Activity without problem, but it doesn't appear in my fragment .
I hope someone find the problem in my code.

Can you make any view show in the fragment? I noticed your MyFragment class is initializing fragment_people.xml but your xml class is named Fragment.xml unless that is a typo. Verify you can show any type of view in your fragment before thinking it is a recycler view issue.
Also, in your adapter, you are using an item layout with name recyclerview_items.xml but you have the class named Recycle item unless that is a typo as well.

It work now, I just changed the fragment to this
public class FriendsFragment extends Fragment {
DatabaseReference databaseReference;
RecyclerView recyclerView;
RecyclerView.Adapter adapter ;
ProgressDialog progressDialog;
List<ImageUploadInfo> list = new ArrayList<>();
private Context context;
public FriendsFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(com.wanjy.dannie.rivchat.R.layout.fragment_people, container, false);
context = view.getContext();
return inflater.inflate(R.layout.fragment_people, container, false);
}
#Override
public void onViewCreated(View view, Bundle savedInstanceState)
{
recyclerView = (RecyclerView) view.findViewById(R.id.recycleListFriend);
progressDialog = new ProgressDialog(context);
progressDialog.setMessage("Loading Images From Firebase.");
progressDialog.show();
databaseReference = FirebaseDatabase.getInstance().getReference("All_Image_Uploads_Database");
databaseReference.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot snapshot) {
for (DataSnapshot postSnapshot : snapshot.getChildren()) {
ImageUploadInfo imageUploadInfo = postSnapshot.getValue(ImageUploadInfo.class);
list.add(imageUploadInfo);
}
adapter = new RecyclerViewAdapter(context, list);
recyclerView.setAdapter(adapter);
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(new LinearLayoutManager(context));
progressDialog.dismiss();
}
#Override
public void onCancelled(DatabaseError databaseError) {
// Hiding the progress dialog.
progressDialog.dismiss();
}
});
super.onViewCreated(view, savedInstanceState);
}
}
I don't what was the problem but, I goggled for an example, and I found someone use method oncreateview
So I did like him , and I moved this line
recyclerView.setLayoutManager(new LinearLayoutManager(context));
to under this line
recyclerView.setAdapter(adapter);
Now it work without problem.

OnClickListener in ViewHolder not being entered

I have a recycler view displaying all posts made by a user in my app. I want the users to be able to click on one of the posts and be brought to a new fragment where they can only see the post they have chosen.
When I run my code, and click on one of the posts, the OnCLickListener isn't even triggered.
I have tried adding break points on public void OnClick but it never gets triggered. I have tried adding the OnClick to the onBindViewHolder but I understand this isn't a good idea.
public class PostAdapter extends RecyclerView.Adapter<PostAdapter.PostViewHolder> {
public List<Post> postList;
private Context context;
private static OnItemClickListener onItemClickListener;
public PostAdapter(){
}
public interface OnItemClickListener{
void onItemClick(View v, int position);
}
public void updateList(List<Post> list){
postList = list;
notifyDataSetChanged();
}
public static class PostViewHolder extends RecyclerView.ViewHolder{
TextView postName, postUsername, postDate, postTime, postContent, postId;
PostViewHolder(View v) {
super(v);
this.postName = (TextView) itemView.findViewById(R.id.name);
this.postUsername = (TextView) itemView.findViewById(R.id.username);
this.postDate = (TextView) itemView.findViewById(R.id.date);
this.postTime = (TextView) itemView.findViewById(R.id.time);
this.postContent = (TextView) itemView.findViewById(R.id.content);
this.postId = (TextView) itemView.findViewById(R.id.postId);
v.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
int position = PostViewHolder.super.getAdapterPosition();
onItemClickListener.onItemClick(v, position);
System.out.println("doesn't even make it here");
}
});
}
}
public PostAdapter(List<Post> postList, Context context){
this.postList = postList;
this.context = context;
}
#Override
public PostAdapter.PostViewHolder onCreateViewHolder(ViewGroup parent, int viewType){
View view = LayoutInflater.from(context).inflate(R.layout.all_posts_layout, parent, false);
return new PostAdapter.PostViewHolder(view);
}
#Override
public void onBindViewHolder(PostViewHolder holder, int position){
Post post = postList.get(position);
holder.postUsername.setText(String.valueOf(post.getUsername()));
holder.postName.setText(String.valueOf(post.getName()));
holder.postDate.setText(String.valueOf(post.getDate()));
holder.postTime.setText(String.valueOf(post.getTime()));
}
#Override
public int getItemCount(){
return this.postList.size();
}
Any help would be very much appreciated!
<---card layout for each individual post---->
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="130dp"
android:orientation="vertical">
<ScrollView
android:layout_width="wrap_content"
android:layout_height="130dp">
<android.support.v7.widget.CardView
android:id="#+id/card_view"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_marginLeft="16dp"
android:layout_marginTop="16dp"
android:layout_marginRight="16dp"
android:layout_marginBottom="2dp"
android:elevation="60dp">
<RelativeLayout
android:id="#+id/search_term_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="1dp">
<TextView
android:id="#+id/name"
android:layout_width="wrap_content"
android:textStyle="bold"
android:layout_height="wrap_content"
android:text="Name"
android:textSize="20sp" />
<TextView
android:id="#+id/username"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textStyle="italic"
android:layout_marginLeft="10dp"
android:layout_toRightOf="#id/name"
android:text="Username"
android:textSize="18sp" />
<TextView
android:id="#+id/date"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#+id/content"
android:layout_alignParentEnd="true"
android:layout_marginEnd="56dp"
android:text="Date"
android:textSize="10sp" />
<TextView
android:id="#+id/time"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBaseline="#+id/username"
android:layout_toRightOf="#+id/username"
android:layout_alignParentEnd="true"
android:paddingLeft="8dp"
android:text="Time"
android:textSize="10sp" />
<TextView
android:id="#+id/content"
android:layout_width="315dp"
android:layout_height="48dp"
android:layout_below="#+id/name"
android:layout_alignStart="#+id/name"
android:text="Content"
android:textSize="18sp" />
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/postId"
android:text="ID"
android:layout_below="#id/content"
/>
</RelativeLayout>
</android.support.v7.widget.CardView>
</ScrollView>
</LinearLayout>
<---recycler view to display all posts------>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:tools="http://schemas.android.com/tools">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/filterBtn"
android:text="Filter"
android:background="#drawable/button"
android:layout_margin="2dp"
android:textColor="#color/common_google_signin_btn_text_dark_default"/>
<android.support.v7.widget.RecyclerView
android:id="#+id/update_post_view"
android:layout_width="match_parent"
android:layout_marginTop="50dp"
android:padding="10dp"
android:layout_height="match_parent" />
</RelativeLayout>

Seems like your ScrollView consumes click event. Try to remove it or replace with NestedScrollView

You need to set it in onCreateViewHolder on that view. Also init it in the constructor.

Update code according to this
public static class PostViewHolder extends RecyclerView.ViewHolder, View.OnClickListener {
TextView postName, postUsername, postDate, postTime, postContent, postId;
PostViewHolder(View v) {
super(v);
//init view
v.setOnClickListener(this);
}
#Override
public void onClick(View v) {
onItemClickListener.onItemClick(v, getAdapterPosition());
}
}

**=> You just need to change onBindViewHolder() method code
=> Add click listener on this method.
=> Your code should be like this.**
#Override
public void onBindViewHolder(PostViewHolder holder, int position){
Post post = postList.get(position);
holder.postUsername.setText(String.valueOf(post.getUsername()));
holder.postName.setText(String.valueOf(post.getName()));
holder.postDate.setText(String.valueOf(post.getDate()));
holder.postTime.setText(String.valueOf(post.getTime()));
holder.itemView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
int position = PostViewHolder.super.getAdapterPosition();
onItemClickListener.onItemClick(v, position);
System.out.println("doesn't even make it here");
}
});
}

Getting the progress of multiple seekbars in recycler view

So I am displaying a recylerview with an Image and the name of a person. Below that is a seekbar, which the user can move to rate that person.
Now I want to store the ratings (=progress) of each seekbar in a list. However right now it only stores the rating of the last seekbar in the list.
So it stores only the progress of the last seekbar right now. I would like that when the user clicks the button that every current rating value of every seekbar is stored in a list.
Thank you very much.
That is is my layout_listitem:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="3dp"
android:id="#+id/parent_layoutREC"
android:orientation="horizontal"
android:layout_marginTop="13dp"
android:gravity="center">
<de.hdodenhof.circleimageview.CircleImageView
android:paddingTop="2dp"
android:paddingLeft="2dp"
android:layout_width="73dp"
android:layout_height="73dp"
android:id="#+id/kunde_imageREC"
android:src="#mipmap/ic_launcher"/>
<TextView
android:layout_marginLeft="40dp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Canada"
android:id="#+id/kunde_nameREC"
android:textColor="#000"
android:textSize="19sp"
android:textStyle="bold"/>
</LinearLayout>
<SeekBar
android:layout_marginRight="35dp"
android:layout_marginLeft="35dp"
android:layout_marginTop="8dp"
android:id="#+id/seek_Bar"
android:max="10"
android:progress="5"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
<TextView
android:gravity="center"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="0 1 2 3 4 5"
android:textSize="20sp"/>
That is my RecyclerViewAdapter class:
public class RecyclerViewAdap extends
RecyclerView.Adapter<RecyclerViewAdap.ViewHolder> {
private static final String TAG = "RecyclerViewAdap";
private ArrayList<String> mImageUrl = new ArrayList<>();
private ArrayList<String> mKundeNamen = new ArrayList<>();
public ArrayList<Integer> mBewertungen = new ArrayList<>();
private Context mContext;
public String bewertung;
private TextView progressSeekbar;
public RecyclerViewAdap(ArrayList<String> imageUrl, ArrayList<String> kundeNamen, Context context) {
mImageUrl = imageUrl;
mKundeNamen = kundeNamen;
mContext = context;
}
public class ViewHolder extends RecyclerView.ViewHolder {
CircleImageView imageView;
TextView kundeName;
LinearLayout parentLayout;
SeekBar seekBar1;
public ViewHolder(#NonNull View itemView) {
super(itemView);
imageView = itemView.findViewById(R.id.kunde_imageREC);
kundeName = itemView.findViewById(R.id.kunde_nameREC);
parentLayout = itemView.findViewById(R.id.parent_layoutREC);
seekBar1 = itemView.findViewById(R.id.seek_Bar);
progressSeekbar = itemView.findViewById(R.id.progress_seekbar);
seekBar1.setOnSeekBarChangeListener(seekBarChangeListener);
//int progress = seekBar1.getProgress();
//String.valueOf(Math.abs((long)progress)).charAt(0);
//progressSeekbar.setText("Bewertung: " +
// String.valueOf(Math.abs((long)progress)).charAt(0) + "." + String.valueOf(Math.abs((long)progress)).charAt(1));
}
}
#NonNull
#Override
public ViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.layout_listitem, parent, false);
ViewHolder holder = new ViewHolder(view);
Log.d(TAG, "onCreateViewHolder: ");
return holder;
}
#Override
public void onBindViewHolder(#NonNull ViewHolder holder, final int position) {
Glide.with(mContext)
.load(mImageUrl.get(position))
.into(holder.imageView);
holder.kundeName.setText(mKundeNamen.get(position));
holder.parentLayout.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Toast.makeText(mContext, mKundeNamen.get(position),
Toast.LENGTH_SHORT).show();
}
});
holder.seekBar1.setTag(position);
}
#Override
public int getItemCount() {
return mImageUrl.size();
}
SeekBar.OnSeekBarChangeListener seekBarChangeListener = new SeekBar.OnSeekBarChangeListener() {
#Override
public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
// updated continuously as the user slides the thumb
progressSeekbar.setText(String.valueOf(progress));
}
#Override
public void onStartTrackingTouch(SeekBar seekBar) {
// called when the user first touches the SeekBar
}
#Override
public void onStopTrackingTouch(SeekBar seekBar) {
// called after the user finishes moving the SeekBar
if (seekBar.getTag().toString().equals("1")) {
mBewertungen.add(seekBar.getProgress());
if (mBewertungen.size() == 2) {
mBewertungen.remove(0);
Toast.makeText(mContext, "onProgressChanged: " + mBewertungen.toString(), Toast.LENGTH_SHORT).show();
}
}
if (seekBar.getTag().toString().equals("2")) {
mBewertungen.add(seekBar.getProgress());
if (mBewertungen.size() == 3) {
mBewertungen.remove(1);
Toast.makeText(mContext, "onProgressChanged: " + mBewertungen.toString(), Toast.LENGTH_SHORT).show();
}
}
}
};
}
That is the activity where the Recyclerview is being displayed:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".BewertungEsserActvity"
android:orientation="vertical"
app:layoutManager="LinearLayoutManager"
android:background="#drawable/gradient_background">
<ScrollView
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<include
android:id="#+id/toolbar"
layout="#layout/toolbar" />
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="14dp"
android:text="Bewerte deine Gäste"
android:textColor="#color/colorDarkGrey"
android:textSize="30sp"
android:textStyle="bold" />
<View
android:layout_width="match_parent"
android:layout_height="1dp"
android:background="#color/colorBlack"
android:layout_marginBottom="10dp"/>
<androidx.recyclerview.widget.RecyclerView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/recycler_view">
</androidx.recyclerview.widget.RecyclerView>
<ProgressBar
android:visibility="invisible"
android:id="#+id/progressbar_4"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="13dp" />
<Button
android:layout_marginRight="66dp"
android:layout_marginLeft="66dp"
android:id="#+id/bewerten_Btn"
android:layout_width="match_parent"
android:layout_height="55dp"
android:layout_marginTop="10dp"
android:background="#drawable/btn_background_profil"
android:padding="10dp"
android:text="Bewerten"
android:textAllCaps="false"
android:textColor="#color/colorWhite"
android:textSize="16sp"
android:textStyle="normal" />
<View
android:layout_marginBottom="10dp"
android:layout_marginTop="34dp"
android:layout_width="match_parent"
android:layout_height="0dp"
android:background="#color/colorBlack" />
</LinearLayout>
</ScrollView>

You can do it in multiple ways:
1- You can store seekbars value as a property in your model and update that property on OnSeekBarChangeListener and when the user hits the button get the data source from the adapter and then run a loop on it and call getter of that attribute.
2- You can store seekbars value as a List<> in your adapter and whenever the user hits the button get the list from the adapter.

Recycler View and Card View not displaying cards

This is my Activity:
public String id;
public String passPhrase;
public ArrayList<SongCell> songs;
private RecyclerView recyclerView;
private MyAdapter myAdapter;
private RecyclerView.LayoutManager layoutManager;
#TargetApi(Build.VERSION_CODES.JELLY_BEAN)
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.songs_view_layout);
Context context = this.getApplicationContext();
Bundle stateData = getIntent().getExtras();
try
{
id = stateData.getString("id");
passPhrase = stateData.getString("passPhrase");
ArrayList data;
recyclerView = (RecyclerView) findViewById(R.id.song_list);
recyclerView.setHasFixedSize(true);
layoutManager = new LinearLayoutManager(this);
recyclerView.setLayoutManager(layoutManager);
recyclerView.setItemAnimator(new DefaultItemAnimator());
data = new ArrayList<SongCell>();
for (int i=0; i<5;i++)
{
data.add(new SongCell("Song "+i,"Artist "+i, null));
}
myAdapter = new MyAdapter(data);
recyclerView.setAdapter(myAdapter);
}
catch(Exception e)
{
Log.d("Error: ", e.toString());
}
}
card.xml
<android.support.v7.widget.CardView android:layout_width="fill_parent"
android:layout_height="wrap_content"
xmlns:android="http://schemas.android.com/apk/res/android">
<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:padding="6dp"
>
<ImageView
android:layout_width="70dp"
android:layout_height="70dp"
android:id="#+id/song_photo"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:layout_marginRight="16dp"
android:background="#drawable/error" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/song_name"
android:textSize="30sp"
android:text="Song Name"
android:layout_centerVertical="true"
android:layout_centerHorizontal="true"
android:textColor="#000000" />
<ImageButton
android:layout_width="60dp"
android:layout_height="60dp"
android:id="#+id/vote_button"
android:layout_alignParentRight="true"
android:layout_marginRight="8dp"
android:background="#drawable/arrow" />
</RelativeLayout>
</android.support.v7.widget.CardView>
Activity.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent" android:layout_height="match_parent"
android:background="#2d2d2d">
<TableLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<TableRow
android:layout_width="fill_parent"
android:layout_height="match_parent"
android:paddingBottom="30dp"
android:layout_marginBottom="10dp"
android:background="#222222"></TableRow>
<TableRow
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:paddingBottom="10dp">
<LinearLayout
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center">
<ImageView
android:layout_width="70dp"
android:layout_height="70dp"
android:id="#+id/featSongImage1"
android:contentDescription="#string/newsongimage"
android:background="#drawable/error" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceSmall"
android:text="#string/songname"
android:id="#+id/featSongName1" />
<ImageButton
android:layout_width="25dp"
android:layout_height="25dp"
android:id="#+id/featSongButt1"
android:background="#drawable/arrow"
android:contentDescription="#string/votearrow" />
</LinearLayout>
</TableRow>
<TableRow
android:layout_width="match_parent"
android:layout_height="match_parent"
android:foregroundGravity="fill_horizontal"
android:gravity="fill_horizontal|center">
<android.support.v7.widget.RecyclerView
android:id="#+id/song_list"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_gravity="center_horizontal" />
</TableRow>
</TableLayout>
</LinearLayout>
And this is my custom adapter
public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder>
{
private ArrayList<SongCell> data;
public MyAdapter(ArrayList<SongCell> dataI)
{
data = dataI;
}
#Override
public ViewHolder onCreateViewHolder(ViewGroup viewGroup, int viewType)
{
View view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.song_card,viewGroup,false);
return new ViewHolder(view);
}
#Override
public void onBindViewHolder(ViewHolder viewholder, int pos) {
viewholder.songName.setText(data.get(pos).getName());
viewholder.artist.setText(data.get(pos).getArtist());
viewholder.image.setImageBitmap(data.get(pos).getArtwork());
}
#Override
public int getItemCount() {
return 0;
}
#Override
public int getItemViewType(int position) {
return 0;
}
public class ViewHolder extends RecyclerView.ViewHolder
{
TextView songName;
TextView artist;
ImageView image;
ImageButton voteButton;
public ViewHolder(View v)
{
super(v);
this.songName = (TextView) v.findViewById(R.id.song_name);
this.image = (ImageView) v.findViewById(R.id.song_photo);
this.voteButton = (ImageButton) v.findViewById(R.id.vote_button);
}
}
}
I have looked at a ton of guides on how to get this working but it still doesn't work. Anyone have any clue what's going on? I'm on version 25.0.1, and have all the modules imported. But it's not adding a single card into the layout.

I thought it would be difficult to debug such a big code you uploaded. But luckily my eye went on this line
#Override
public int getItemCount() {
return 0;
}
return 0; in adapter.
Your list size is always 0.
instead write this
#Override
public int getItemCount() {
return data.size();
}
EDIT-1:
You will also get null pointer exception here
viewholder.artist.setText(data.get(pos).getArtist());
Because you are not initializing the artist variable in ViewHolder class.
Edit-2
#Override
public int getItemCount() {
return 0;
}
you can remove this particular code from your adapter. Because overriding the methods of class that we don't use might sometimes result in errors that you can't even imagine.