Get RecyclerViewAdapter onclick position in main activity

You can achieve this by creating an interface inside 

your adapter for an itemclicklistener and then you can

 set onItemClickListener from your MainActivity.

Somewhere inside your RecyclerViewAdapter you would

 need the following:



private onRecyclerViewItemClickListener mItemClickListener;


public void setOnItemClickListener(onRecyclerViewItemClickListener mItemClickListener) {

    this.mItemClickListener = mItemClickListener;
}


public interface onRecyclerViewItemClickListener {

    void onItemClickListener(View view, int position);
}


Then inside your ViewHolder (which I've added as an inner class inside my adapter),

 you would apply the listener to the components you'd like the user to click, like so:

 class RecyclerViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {

    public ImageView imageview;

    RecyclerViewHolder(View view) {

        super(view);

        this.imageview = (ImageView) view

                .findViewById(R.id.image);

        imageview.setOnClickListener(this);
    }


    @Override

    public void onClick(View v) {

        if (mItemClickListener != null) {

            mItemClickListener.onItemClickListener(v, getAdapterPosition());
        }
    }
}

This example shows an onClickListener being applied to the image inside a ViewHolder.
To implement this code, you would setOnItemClickListener to your adapter 

inside MainActivity as shown above.


 recyclerView.setAdapter(adapter);// set adapter on recyclerview

            adapter.notifyDataSetChanged();// Notify the adapter

            adapter.setOnItemClickListener(new RecyclerViewAdapter.onRecyclerViewItemClickListener() {

    @Override

    public void onItemClickListener(View view, int position) {

        Switch (view.getId()) {

            case R.id.letter:
                //logic here
                break;

            case R.id.firstname:

                //logic here
                break;
        ....            

        }
    }
});

How to use fragment method in Main Activity class

Create interface

public interface ListenFromActivity {    void doSomethingInFragment();}

In Activity class keep refrence of ListenFromActivity interface

public ListenFromActivity activityListener;   

Make public method to set listener

public void setActivityListener(ListenFromActivity activityListener) {        this.activityListener = activityListener;    }

Add some trigger point in activity class, here I have used user interaction

   @Override    public void onUserInteraction() {        super.onUserInteraction();

        if (null != activityListener) {            activityListener.doSomethingInFragment();        }    }

Now in Fragment class

make your fragment implement interface class

public class SomeFragment extends Fragment implements ListenFromActivity

Android studio will prompt you to implement method of interface in fragment

void doSomethingInFragment(){//Add your code here }

Final part part listener instance to activity like this in fragment onCreate method

((ListnerActivity) getActivity()).setActivityListener(SomeFragment.this);

DONE!!. now you can call fragment method from activity.