Android Call a method from adapter

Question

I have a method in a fragment that I want to call when user clicks a recyclerview item. For example

holder.addButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                //call the method in fragment
                //e.g.  activity instance context dot(.) method name
                mainActivity.refreshData();
            }
   }

In main activity it will be simple as

public void refreshData(){
     // refresh
}

Answer 1

Create an interface of a click listener:

interface ItemClickListener {
    void onItemClick();
}

Add this listener to your RecyclerView adapter's constructor:

private final ItemClickListener itemClickListener;

public MyAdapter(ItemClickListener itemClickListener) {
    this.itemClickListener = itemClickListener;
}

And add there the click listener for your addButton:

holder.addButton.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        itemClickListener.onItemClick();
    }
}

Pass the implementation of ItemClickListener interface to your adapter in your activity class, for example like this:

MyAdapter adapter = new MyAdapter(() -> refreshData());