การทำงานกับ RecyclerView ในแอป Android

ภาพรวม

ตัวอย่างนี้สาธิตการใช้ RecyclerView แสดงรายการหนังพร้อม CardView LayoutManager และ Adapter แบบสมบูรณ์

ขั้นตอนที่ 1: สร้างโปรเจกต์ใหม่

เปิด Android Studio ไปที่ File → New Project กรอกข้อมูลที่จำเป็น

ขั้นตอนที่ 2: จัดรูปแบบหน้าจอหลัก (activity_main.xml)

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="https://schemas.android.com/apk/res/android"
    android:id="@+id/rlMain"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_margin="16dp"
    android:orientation="vertical">
    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/recyclerView"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />
</LinearLayout>

ขั้นตอนที่ 3: โมเดลข้อมูล (MovieModel.java)

package app.com.sample;

public class MovieModel {
    private String title, genre, year;

    public MovieModel() {}

    public MovieModel(String title, String genre, String year) {
        this.title = title;
        this.genre = genre;
        this.year = year;
    }

    public String getTitle() { return title; }
    public void setTitle(String name) { this.title = name; }
    public String getYear() { return year; }
    public void setYear(String year) { this.year = year; }
    public String getGenre() { return genre; }
    public void setGenre(String genre) { this.genre = genre; }
}

ขั้นตอนที่ 4: Layout รายการ (res/layout/movies_list.xml)

<?xml version="1.0" encoding="utf-8"?>
<androidx.cardview.widget.CardView xmlns:android="https://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="100dp"
    android:layout_margin="8dp">
    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:padding="8dp">
        <TextView
            android:id="@+id/title"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_alignParentStart="true"
            android:layout_toStartOf="@+id/year"
            android:textColor="#222222"
            android:textSize="16sp"
            android:textStyle="bold" />
        <TextView
            android:id="@+id/year"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentEnd="true"
            android:textColor="#999999" />
        <TextView
            android:id="@+id/genre"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_alignParentBottom="true" />
    </RelativeLayout>
</androidx.cardview.widget.CardView>

ขั้นตอนที่ 5: Adapter (MoviesAdapter.java)

package app.com.sample;

import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;
import java.util.List;

public class MoviesAdapter extends RecyclerView.Adapter<MoviesAdapter.MyViewHolder> {
    private List<MovieModel> moviesList;

    class MyViewHolder extends RecyclerView.ViewHolder {
        TextView title, year, genre;
        MyViewHolder(View view) {
            super(view);
            title = view.findViewById(R.id.title);
            genre = view.findViewById(R.id.genre);
            year = view.findViewById(R.id.year);
        }
    }

    public MoviesAdapter(List<MovieModel> moviesList) {
        this.moviesList = moviesList;
    }

    @NonNull
    @Override
    public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View itemView = LayoutInflater.from(parent.getContext())
            .inflate(R.layout.movie_list, parent, false);
        return new MyViewHolder(itemView);
    }

    @Override
    public void onBindViewHolder(MyViewHolder holder, int position) {
        MovieModel movie = moviesList.get(position);
        holder.title.setText(movie.getTitle());
        holder.genre.setText(movie.getGenre());
        holder.year.setText(movie.getYear());
    }

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

ขั้นตอนที่ 6: MainActivity.java

package app.com.sample;

import android.os.Bundle;
import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.DefaultItemAnimator;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity {
    private List<MovieModel> movieList = new ArrayList<>();
    private MoviesAdapter mAdapter;

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

        RecyclerView recyclerView = findViewById(R.id.recyclerView);
        mAdapter = new MoviesAdapter(movieList);
        LinearLayoutManager mLayoutManager = new LinearLayoutManager(getApplicationContext());
        recyclerView.setLayoutManager(mLayoutManager);
        recyclerView.setItemAnimator(new DefaultItemAnimator());
        recyclerView.setAdapter(mAdapter);

        prepareMovieData();
    }

    private void prepareMovieData() {
        movieList.add(new MovieModel("Mad Max: Fury Road", "Action & Adventure", "2015"));
        movieList.add(new MovieModel("Inside Out", "Animation, Kids & Family", "2015"));
        movieList.add(new MovieModel("Star Wars: Episode VII - The Force Awakens", "Action", "2015"));
        movieList.add(new MovieModel("Shaun the Sheep", "Animation", "2015"));
        movieList.add(new MovieModel("The Martian", "Science Fiction & Fantasy", "2015"));
        movieList.add(new MovieModel("Mission: Impossible Rogue Nation", "Action", "2015"));
        movieList.add(new MovieModel("Up", "Animation", "2009"));
        movieList.add(new MovieModel("Star Trek", "Science Fiction", "2009"));
        movieList.add(new MovieModel("The LEGO Movie", "Animation", "2014"));
        movieList.add(new MovieModel("Iron Man", "Action & Adventure", "2008"));
        movieList.add(new MovieModel("Aliens", "Science Fiction", "1986"));
        movieList.add(new MovieModel("Chicken Run", "Animation", "2000"));
        movieList.add(new MovieModel("Back to the Future", "Science Fiction", "1985"));
        movieList.add(new MovieModel("Raiders of the Lost Ark", "Action & Adventure", "1981"));
        movieList.add(new MovieModel("Goldfinger", "Action & Adventure", "1965"));
        movieList.add(new MovieModel("Guardians of the Galaxy", "Science Fiction & Fantasy", "2014"));
        mAdapter.notifyDataSetChanged();
    }
}

ขั้นตอนที่ 7: AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="https://schemas.android.com/apk/res/android"
    package="app.com.sample">
    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>
</manifest>

การทดสอบ

รันแอป จะแสดงรายการหนังใน RecyclerView แบบ CardView พร้อมเลื่อนได้อย่างราบรื่น