Question

我已经检查了在互联网上找到的所有内容。我不知道为什么RecyclerView没有显示任何项目。虽然没有显示任何错误。有我的适配器类

import android.content.Context;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import java.util.ArrayList;

public class bookAdapter extends 
RecyclerView.Adapter<bookAdapter.bookViewHolder> {

ArrayList<Book> arrayList;
TextView bookNameTV;
TextView authorNameTV;

public bookAdapter(ArrayList<Book> arrayList){
    this.arrayList = arrayList;
    }

@Override
public bookViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    Context context = parent.getContext();
    View view = 
LayoutInflater.from(context).inflate(R.layout.book_list_item,parent,false);
    return new bookViewHolder(view);
}

@Override
public void onBindViewHolder(bookViewHolder holder, int position) {
    Book book = arrayList.get(position);
    //holder.bind(book);
    bookNameTV.setText(book.getBook());
    authorNameTV.setText(book.getAuthor());


}

@Override
public int getItemCount() {
    return 0;
}

public class bookViewHolder extends RecyclerView.ViewHolder{



    public bookViewHolder(View itemView) {
        super(itemView);
        bookNameTV = (TextView) itemView.findViewById(R.id.book_name);
        authorNameTV = (TextView) itemView.findViewById(R.id.author_name);
    }

    public void bind(Book book){
        bookNameTV.setText(Book.book);
        authorNameTV.setText(Book.author);
        }
    }
}

这是Book类，具有要显示的信息：

public class Book {
public static String book;
public static String author;

Book(String book, String author){
    this.book = book;
    this.author = author;
    }

public String getBook() {
    return book;
}

public void setBook(String book) {
    this.book = book;
}

public String getAuthor() {
    return author;
}

public void setAuthor(String author) {
    this.author = author;
}

这是Main Activity，正在初始化Book和Adapter类：公共类MainActivity扩展了AppCompatActivity {

ArrayList<Book> arrayList = new ArrayList<Book>();
RecyclerView recyclerView;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    recyclerView = findViewById(R.id.rvContacts);
    recyclerView.setHasFixedSize(true);//also checked by removing this line
    recyclerView.setLayoutManager(new 
LinearLayoutManager(getApplicationContext()));

    arrayList.add(new Book("Power","Burhan"));
    arrayList.add(new Book("influence","Burhan Sabir"));
    bookAdapter book_Adapter =  new bookAdapter(arrayList);
    book_Adapter.notifyDataSetChanged();
    recyclerView.setAdapter(book_Adapter);

   }
}}

我认为此“ build.gradle”文件可能存在一些问题。但这没有给出任何错误。

您也可以查看布局文件。这个main.xml文件：

<android.support.constraint.ConstraintLayout 
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent">

<android.support.v7.widget.RecyclerView
    android:id="@+id/rvContacts"
    android:layout_width="0dp"
    android:layout_height="0dp"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent" />

book_list_item.xml文件为：

<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:paddingTop="10dp"
android:paddingBottom="10dp"
>

<TextView
    android:id="@+id/book_name"
    android:layout_width="0dp"
    android:layout_height="wrap_content"
    android:layout_weight="1"
    />

<TextView
    android:id="@+id/author_name"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:paddingLeft="16dp"
    android:paddingRight="16dp"
    android:textSize="10sp"
    />
</LinearLayout>

谢谢..

RecyclerView没有显示项目

0 个答案: