[Android] Simple Android RecyclerView example
url: https://stackoverflow.com/questions/40584424/simple-android-recyclerview-example
url: https://stackoverflow.com/questions/28460300/how-to-build-a-horizontal-listview-with-recyclerview/28460399
The following is a minimal example that will look like the following image.
Start with an empty activity. You will perform the following tasks to add the RecyclerView. All you need to do is copy and paste the code in each section. Later you can customize it to fit your needs.
- Add dependencies to gradle
- Add the xml layout files for the activity and for the RecyclerView row
- Make the RecyclerView adapter
- Initialize the RecyclerView in your activity
Update Gradle dependencies
Make sure the following dependencies are in your app gradle.build file:
implementation 'com.android.support:appcompat-v7:27.1.1'
implementation 'com.android.support:recyclerview-v7:27.1.1'You can update the version numbers to whatever is the most current. Use compile rather than implementation if you are still using Android Studio 2.x.
Create activity layout
Add the RecyclerView to your xml layout.
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v7.widget.RecyclerView
android:id="@+id/rvAnimals"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</RelativeLayout>Create row layout
Each row in our RecyclerView is only going to have a single TextView. Create a new layout resource file.
recyclerview_row.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:padding="10dp">
<TextView
android:id="@+id/tvAnimalName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="20sp"/>
</LinearLayout>Create the adapter
The RecyclerView needs an adapter to populate the views in each row with your data. Create a new java file.
MyRecyclerViewAdapter.java
public class MyRecyclerViewAdapter extends RecyclerView.Adapter<MyRecyclerViewAdapter.ViewHolder> {
private List<String> mData;
private LayoutInflater mInflater;
private ItemClickListener mClickListener;
// data is passed into the constructor
MyRecyclerViewAdapter(Context context, List<String> data) {
this.mInflater = LayoutInflater.from(context);
this.mData = data;
}
// inflates the row layout from xml when needed
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = mInflater.inflate(R.layout.recyclerview_row, parent, false);
return new ViewHolder(view);
}
// binds the data to the TextView in each row
@Override
public void onBindViewHolder(ViewHolder holder, int position) {
String animal = mData.get(position);
holder.myTextView.setText(animal);
}
// total number of rows
@Override
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.tvAnimalName);
itemView.setOnClickListener(this);