Simple Android grid example using RecyclerView with GridLayoutManager (like the old GridView)
android, android-recyclerview, gridlayoutmanager, gridview
Solution
Short answer
For those who are already familiar with setting up a `RecyclerView` to make a list, the good news is that making a grid is largely the same. You just use a `GridLayoutManager` instead of a `LinearLayoutManager` when you set the `RecyclerView` up.
recyclerView.setLayoutManager(new GridLayoutManager(this, numberOfColumns));
If you need more help than that, then check out the following example.
Full example
The following is a minimal example that will look like the image below.
Start with an empty activity. You will perform the following tasks to add the `RecyclerView` grid. 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 grid cell
- 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:
compile 'com.android.support:appcompat-v7:27.1.1'
compile 'com.android.support:recyclerview-v7:27.1.1'
You can update the version numbers to whatever is the most current.
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/rvNumbers"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</RelativeLayout>
Create grid cell layout
Each cell in our `RecyclerView` grid is only going to have a single `TextView`. Create a new layout resource file.
recyclerview_item.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal"
android:padding="5dp"
android:layout_width="50dp"
android:layout_height="50dp">
<TextView
android:id="@+id/info_text"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:background="@color/colorAccent"/>
</LinearLayout>
Create the adapter
The `RecyclerView` needs an adapter to populate the views in each cell with your data. Create a new java file.
MyRecyclerViewAdapter.java
public class MyRecyclerViewAdapter extends RecyclerView.Adapter<MyRecyclerViewAdapter.ViewHolder> {
private String[] mData;
private LayoutInflater mInflater;
private ItemClickListener mClickListener;
// data is passed into the constructor
MyRecyclerViewAdapter(Context context, String[] data) {
this.mInflater = LayoutInflater.from(context);
this.mData = data;
}
// inflates the cell layout from xml when needed
@Override
@NonNull
public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
View view = mInflater.inflate(R.layout.recyclerview_item, parent, false);
return new ViewHolder(view);
}
// binds the data to the TextView in each cell
@Override
public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
holder.myTextView.setText(mData[position]);
}
// total number of cells
@Override
public int getItemCount() {
return mData.length;
}
// 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.info_text);
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[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);
}
}
Notes
- Although not strictly necessary, I included the functionality for listening for click events on the cells. This was available in the old `GridView` and is a common need. You can remove this code if you don't need it.
Initialize RecyclerView in Activity
Add the following code to your main activity.
MainActivity.java
public class MainActivity extends AppCompatActivity implements MyRecyclerViewAdapter.ItemClickListener {
MyRecyclerViewAdapter adapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// data to populate the RecyclerView with
String[] data = {"1", "2", "3", "4", "5", "6", "7", "8", "9", "10", "11", "12", "13", "14", "15", "16", "17", "18", "19", "20", "21", "22", "23", "24", "25", "26", "27", "28", "29", "30", "31", "32", "33", "34", "35", "36", "37", "38", "39", "40", "41", "42", "43", "44", "45", "46", "47", "48"};
// set up the RecyclerView
RecyclerView recyclerView = findViewById(R.id.rvNumbers);
int numberOfColumns = 6;
recyclerView.setLayoutManager(new GridLayoutManager(this, numberOfColumns));
adapter = new MyRecyclerViewAdapter(this, data);
adapter.setClickListener(this);
recyclerView.setAdapter(adapter);
}
@Override
public void onItemClick(View view, int position) {
Log.i("TAG", "You clicked number " + adapter.getItem(position) + ", which is at cell position " + position);
}
}
Notes
- Notice that the activity implements the `ItemClickListener` that we defined in our adapter. This allows us to handle cell click events in `onItemClick`.
Finished
That's it. You should be able to run your project now and get something similar to the image at the top.
Going on
Rounded corners
- Use a CardView
Auto-fitting columns
- GridLayoutManager - how to auto fit columns?
Further study
- Android RecyclerView with GridView GridLayoutManager example tutorial
- Android RecyclerView Grid Layout Example
- Learn RecyclerView With an Example in Android
- RecyclerView: Grid with header
- Android GridLayoutManager with RecyclerView in Material Design
- Getting Started With RecyclerView and CardView on Android
Problem
I know that `RecyclerView` has replaced the functionality of the old `ListView` and `GridView`. I am looking for a very basic example that shows a minimal grid setup using `RecyclerView`. I am not looking for long tutorial style explanations, just a minimal example. I imagine the simplest grid that mimics the old GridView would consist of the following features: - multiple cells per row - single view in each cell - responds to click events