RecyclerView 返回的 ListAdapter 应该是抽象错误

Question

在UserListAdapter

public class UserListAdapter extends RecyclerView.Adapter 

给出这个错误

Class UserListAdapter must either be declared abstract or implement abstract method onBindViewHolder(VH, int) in Adapter

我已经查看了有关堆栈溢出的其他答案，但我没有找到任何可以修复错误的方法。

UserListAdapter.java

public class UserListAdapter extends RecyclerView.Adapter {

private List<String> mData;
private LayoutInflater mInflater;
private ItemClickListener mClickListener;

// data is passed into the constructor
UserListAdapter(Context context, List<String> data) {
    this.mInflater = LayoutInflater.from(context);
    this.mData = data;
}

// inflates the row layout from xml when needed
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    View view = mInflater.inflate(R.layout.user_layout, parent, false);
    return new ViewHolder(view);
}

// binds the data to the TextView in each row
public void onBindViewHolder(ViewHolder holder, int position) {
    String animal = mData.get(position);
    holder.myTextView.setText(animal);
}

// total number of rows
public int getItemCount() {
    return mData.size();
}


// stores and recycles views as they are scrolled off screen
public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
    TextView myTextView;

    ViewHolder(View itemView) {
        super(itemView);
        myTextView = itemView.findViewById(R.id.txtStudentNameSubjectInfoPage);
        itemView.setOnClickListener(this);
    }

    @Override
    public void onClick(View view) {
        if (mClickListener != null) mClickListener.onItemClick(view, getAdapterPosition());
    }
}

// convenience method for getting data at click position
String getItem(int id) {
    return mData.get(id);
}

// allows clicks events to be caught
void setClickListener(ItemClickListener itemClickListener) {
    this.mClickListener = itemClickListener;
}

// parent activity will implement this method to respond to click events
public interface ItemClickListener {
    void onItemClick(View view, int position);
}
}

user_layout.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.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="wrap_content"
android:paddingTop="8dp">

<ImageView
    android:id="@+id/imgStudentIconSubjectInfoPage"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginStart="8dp"
    android:layout_marginTop="8dp"
    android:layout_marginBottom="8dp"
    android:layout_weight="1"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    tools:srcCompat="@tools:sample/avatars[13]" />

<TextView
    android:id="@+id/txtStudentNameSubjectInfoPage"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginStart="8dp"
    android:layout_marginTop="16dp"
    android:layout_marginEnd="8dp"
    android:layout_marginBottom="8dp"
    android:layout_weight="1"
    android:gravity="center_vertical"
    android:text="User Name"
    android:textAlignment="center"
    android:textColor="#292929"
    android:textSize="20sp"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintHorizontal_bias="0.1"

app:layout_constraintStart_toEndOf="@+id/imgStudentIconSubjectInfoPage"
    app:layout_constraintTop_toTopOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>

activity_subject_info_page.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.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=".SubjectInfoPage">

<androidx.recyclerview.widget.RecyclerView
    android:id="@+id/recyclerView"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_marginTop="32dp"
    app:layout_constraintTop_toBottomOf="@+id/tableLayout"
    tools:layout_editor_absoluteX="0dp" />

</androidx.constraintlayout.widget.ConstraintLayout>

Answer 1

父类RecyclerView.Adapter 与您自定义的Viewholder 与它自己的混淆。如果你想使用你的，请扩展RecyclerView.Adapter如下

public class UserListAdapter extends RecyclerView.Adapter<UserListAdapter.ViewHolder>
{
   .......
}

干杯:)