java - RecyclerView 返回的 ListAdapter 应该是抽象错误

Question

在UserListAdapter

中

public class UserListAdapter extends RecyclerView.Adapter 

出现此错误

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

我已经研究了有关堆栈溢出的其他答案，但没有找到任何可以修复该错误的内容。

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与您的自定义Viewholder及其自身的定义相混淆。如果您想使用自己的适配器，请按如下方式扩展 RecyclerView.Adapter

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

干杯:)