Android – RecyclerView 1

In deze reeks van code snippets wordt getoond hoe een simpele RecyclerView is op te bouwen met 6 handmatige items inclusief standaard iconen.
Android Studio 4.0.0
Projectnaam RVPTH
SDK API 19
Bron https://www.javatpoint.com/android-recyclerview-list-example


dependencies {
    implementation fileTree(dir: "libs", include: ["*.jar"])
    implementation 'androidx.appcompat:appcompat:1.2.0'
    implementation 'androidx.constraintlayout:constraintlayout:2.0.4'
    implementation 'androidx.recyclerview:recyclerview:1.1.0'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'androidx.test.ext:junit:1.1.2'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.3.0'
}


<?xml version="1.0" encoding="utf-8"?>
<androidx.recyclerview.widget.RecyclerView
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:scrollbars="vertical"
    android:id="@+id/recyclerView"
    tools:context="com.example.rvpth.MainActivity">
</androidx.recyclerview.widget.RecyclerView>

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <dimen name="activity_horizontal_margin">16dp</dimen>
    <dimen name="activity_vertical_margin">16dp</dimen>
    <dimen name="ic_clear_margin">56dp</dimen>
</resources>
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/relativeLayout"
    android:layout_width="match_parent"
    android:layout_height="?android:attr/listPreferredItemHeightLarge"
    android:background="@drawable/border">

    <ImageView
        android:id="@+id/imageView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerVertical="true"
        android:layout_alignParentStart="true"
        android:layout_alignParentLeft="true"
        android:layout_marginStart="@dimen/activity_horizontal_margin"
        android:layout_marginEnd="@dimen/activity_horizontal_margin"
        android:contentDescription="Icon" />

    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:layout_toEndOf="@id/imageView"
        android:layout_toRightOf="@id/imageView"
        android:gravity="center_vertical"
        android:textSize="16sp"/>

</RelativeLayout>
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">
    <solid android:color="#FFFFFF" />
    <stroke
        android:width="1dp"
        android:color="#CCCCCC" />
</shape>
public class MyListData{
    private String description;
    private int imgId;
    public MyListData(String description, int imgId) {
        this.description = description;
        this.imgId = imgId;
    }
    public String getDescription() {
        return description;
    }
    public void setDescription(String description) {
        this.description = description;
    }
    public int getImgId() {
        return imgId;
    }
    public void setImgId(int imgId) {
        this.imgId = imgId;
    }
}
public class MyListAdapter extends RecyclerView.Adapter<MyListAdapter.ViewHolder>{

    private MyListData[] listdata;

    public MyListAdapter(List<MyListData> listdata) {
        this.listdata = listdata.toArray(new MyListData[0]);
    }
    @Override
    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        LayoutInflater layoutInflater = LayoutInflater.from(parent.getContext());
        View listItem= layoutInflater.inflate(R.layout.list_item, parent, false);
        ViewHolder viewHolder = new ViewHolder(listItem);
        return viewHolder;
    }

    @Override
    public void onBindViewHolder(ViewHolder holder, int position) {
        final MyListData myListData = listdata[position];
        holder.textView.setText(listdata[position].getDescription());
        holder.imageView.setImageResource(listdata[position].getImgId());
        holder.relativeLayout.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Toast.makeText(view.getContext(),"click on item: "+myListData.getDescription(),Toast.LENGTH_LONG).show();
            }
        });
    }

    @Override
    public int getItemCount() {
        return listdata.length;
    }

    public static class ViewHolder extends RecyclerView.ViewHolder {
        public ImageView imageView;
        public TextView textView;
        public RelativeLayout relativeLayout;
        public ViewHolder(View itemView) {
            super(itemView);
            this.imageView = (ImageView) itemView.findViewById(R.id.imageView);
            this.textView = (TextView) itemView.findViewById(R.id.textView);
            relativeLayout = (RelativeLayout)itemView.findViewById(R.id.relativeLayout);
        }
    }
}
public class MainActivity extends AppCompatActivity {

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

        final List<MyListData> myListData = new ArrayList<MyListData>();
        RecyclerView recyclerView = (RecyclerView) findViewById(R.id.recyclerView);

        myListData.add(new MyListData("Email", android.R.drawable.ic_dialog_email));
        myListData.add(new MyListData("Info", android.R.drawable.ic_dialog_info));
        myListData.add(new MyListData("Delete", android.R.drawable.ic_delete));
        myListData.add(new MyListData("Dialer", android.R.drawable.ic_dialog_dialer));
        myListData.add(new MyListData("Alert", android.R.drawable.ic_dialog_alert));
        myListData.add(new MyListData("Map", android.R.drawable.ic_dialog_map));

        final MyListAdapter adapter = new MyListAdapter(myListData);

        recyclerView.setHasFixedSize(true);
        recyclerView.setLayoutManager(new LinearLayoutManager(this));
        recyclerView.setAdapter(adapter);
    }
}