Android RecyclerView with different layouts doesn't work

Question

I am trying to implement a RecyclerView with two different layouts. In the MainActivity I first create ListItem object and add it to the list and then add that to the adapter, but it doesn't show. And also I am calling a method that creates ListItem object and adds it to the list and then notifies the adapter, but it still doesn't show. Here is my code so far:

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout 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="nl.iansoft.www.recyclerviewproblem.MainActivity">

    <android.support.v7.widget.RecyclerView
        android:id="@+id/rvList"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_marginBottom="100dp"
        />

</android.support.constraint.ConstraintLayout>

MainActivity.java

public class MainActivity extends AppCompatActivity {

    private ArrayList<ListItem> listItems;
    private CustomAdapter customAdapter;
    private RecyclerView rvList;

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

        rvList = (RecyclerView)findViewById(R.id.rvList);
        listItems = new ArrayList<>();
        ListItem listItem = new ListItem("MyName", "MyLatsName", "MyEmail");
        listItems.add(listItem);
        customAdapter = new CustomAdapter(listItems);
        RecyclerView.LayoutManager mLayoutManager = new LinearLayoutManager(this);
        rvList.setLayoutManager(mLayoutManager);
        rvList.setItemAnimator(new DefaultItemAnimator());
        rvList.setAdapter(customAdapter);

        addItemToTheList();
    }

    private void addItemToTheList(){
        ListItem listItem = new ListItem("MyName", "MyLatsName", "MyEmail");
        listItems.add(listItem);
        customAdapter.notifyDataSetChanged();
    }
}

CustomAdapter.java

public class CustomAdapter  extends RecyclerView.Adapter<RecyclerView.ViewHolder> {

    private ArrayList<ListItem> listItems;

    public class ListItem1ViewHolder extends RecyclerView.ViewHolder {
        public TextView tvName;
        public TextView tvLastName;
        public TextView tvEmail;

        public ListItem1ViewHolder(View view) {
            super(view);
            tvName = (TextView) view.findViewById(R.id.tvName);
            tvLastName = (TextView) view.findViewById(R.id.tvLastName);
            tvEmail = (TextView) view.findViewById(R.id.tvEmail);
        }
    }

    public class ListItem2ViewHolder extends RecyclerView.ViewHolder {

        public TextView tvName2;
        public TextView tvLastName2;
        public TextView tvEmail2;

        public ListItem2ViewHolder(View view) {
            super(view);

            tvName2 = (TextView) view.findViewById(R.id.tvName2);
            tvLastName2 = (TextView) view.findViewById(R.id.tvLastName2);
            tvEmail2 = (TextView) view.findViewById(R.id.tvEmail2);
        }
    }


    public CustomAdapter(ArrayList<ListItem> listItems) {
        this.listItems = listItems;
    }

    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View itemView;
        if(viewType == 1){
            itemView = LayoutInflater.from(parent.getContext())
                    .inflate(R.layout.my_list_item, parent, false);
            return new CustomAdapter.ListItem1ViewHolder(itemView);
        }else{
            itemView = LayoutInflater.from(parent.getContext())
                    .inflate(R.layout.my_list_item2, parent, false);
            return new CustomAdapter.ListItem2ViewHolder(itemView);
        }
    }

    @Override
    public int getItemViewType(int position) {
        if(listItems.get(position).getName().equals("MyName")){
            return 1;
        }else{
            return 2;
        }
    }

    @Override
    public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
        ListItem listItem = listItems.get(position);
        if(holder.getItemViewType() == 1) {
            ListItem1ViewHolder listItem1ViewHolder = (ListItem1ViewHolder) holder;
            listItem1ViewHolder.tvName.setText(listItem.getName());
            listItem1ViewHolder.tvLastName.setText(listItem.getLastName());
            listItem1ViewHolder.tvEmail.setText(listItem.getEmail());
        }else{
            ListItem2ViewHolder listItem2ViewHolder = (ListItem2ViewHolder)holder;
            listItem2ViewHolder.tvName2.setText(listItem.getName());
            listItem2ViewHolder.tvLastName2.setText(listItem.getLastName());
            listItem2ViewHolder.tvEmail2.setText(listItem.getEmail());
        }
    }

    @Override
    public int getItemCount() {
        return listItems.size();
    }
}

ListItem.java

public class ListItem {

    private String name;
    private String lastName;
    private String email;

    public ListItem() {
    }

    public ListItem(String name, String lastName, String email) {
        this.name = name;
        this.lastName = lastName;
        this.email = email;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }
}

my_list_item2.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content">

    <TextView
        android:id="@+id/tvName2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="14sp"
        android:text="Name2"
        android:layout_marginTop="15dp"
        android:padding="5dp"/>

    <TextView
        android:id="@+id/tvLastName2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="16sp"
        android:text="Last Name2"
        android:layout_below="@+id/tvName2"
        android:layout_marginTop="10dp"
        android:padding="5dp" />

    <TextView
        android:id="@+id/tvEmail2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="14sp"
        android:text="my@email.com"
        android:layout_below="@+id/tvLastName2"
        android:layout_marginTop="5dp"
        android:padding="5dp" />

</RelativeLayout>

my_list_item.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content">

    <TextView
        android:id="@+id/tvName"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="14sp"
        android:text="Name"
        android:layout_marginTop="15dp"
        android:padding="5dp"/>

    <TextView
        android:id="@+id/tvLastName"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="16sp"
        android:text="Last Name"
        android:layout_below="@+id/tvName"
        android:layout_marginTop="10dp"
        android:padding="5dp" />

    <TextView
        android:id="@+id/tvEmail"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="14sp"
        android:text="my@email.com"
        android:layout_below="@+id/tvLastName"
        android:layout_marginTop="5dp"
        android:padding="5dp" />

</RelativeLayout>

Answer 1

The issue is in ConstraintLayout. Because you haven't specified any constraints to your RecyclerView.

Either specify constraints, or move to another layout (e.g. FrameLayout).

But specifically in this case you do not need parent layout, because it is useless, as long as you have only RecyclerView in your view hierarchy.