why is this crashing ? how to fix? : well im doing a recycler view with a database on firebase . that is working perfectly... now i want to implement a share button  but i cant make the button reference each  img. i found a tutorial to do so but when i try to implement this line  (if i remove it the apps goes well but doest reference to the button position)
public BlogViewHolder(View itemView) {    
              ...
               button = (Button)mView.findViewById(R.id.share);

                   ...
the app crashes when i open the activity
im only using toast to testing.
i relay apreciate replies pardon my english  and pardon the post im new to android develop and its my 1time here on stack, regards















    import android.content.Context;
    import android.content.Intent;
    import android.net.ConnectivityManager;
    import android.net.Uri;
    import android.support.v7.app.AppCompatActivity;
    import android.os.Bundle;
    import android.support.v7.widget.LinearLayoutManager;
    import android.support.v7.widget.RecyclerView;
    import android.util.Log;
    import android.view.View;
    import android.widget.AdapterView;
    import android.widget.ArrayAdapter;
    import android.widget.Button;
    import android.widget.ImageView;
    import android.widget.ListView;
    import android.widget.TextView;
    import android.widget.Toast;
    
    import com.firebase.ui.database.FirebaseRecyclerAdapter;
    import com.google.android.gms.analytics.HitBuilders;
    import com.google.android.gms.analytics.Tracker;
    import com.google.firebase.database.ChildEventListener;
    import com.google.firebase.database.DataSnapshot;
    import com.google.firebase.database.DatabaseError;
    import com.google.firebase.database.DatabaseReference;
    import com.google.firebase.database.FirebaseDatabase;
    import com.google.firebase.database.ValueEventListener;
    import com.squareup.picasso.Picasso;
    
    import java.util.ArrayList;
    
    public class NoticiasActivity extends AppCompatActivity {
    
        private RecyclerView mBlogList;
        FirebaseDatabase database;
        DatabaseReference myRef;
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_noticias);
    
            //Recycler View
            mBlogList = (RecyclerView)findViewById(R.id.blog_list);
            mBlogList.setHasFixedSize(true);
            mBlogList.setLayoutManager(new LinearLayoutManager(this));
    
            // Send a Query to the database
            database = FirebaseDatabase.getInstance();
            myRef = database.getReference("Data");
        }
    
        @Override
        protected void onStart() {
            super.onStart();
    
            FirebaseRecyclerAdapter<ModelClass, BlogViewHolder> firebaseRecyclerAdapter =
                    new FirebaseRecyclerAdapter<ModelClass, BlogViewHolder>(
                            ModelClass.class,
                            R.layout.design_row,
                            BlogViewHolder.class,
                            myRef)  {
    
    
    
                        @Override
                        protected void populateViewHolder(BlogViewHolder viewHolder, ModelClass model,int position) {
                            viewHolder.setTitle(model.getTitle());
                            viewHolder.setImage(getApplicationContext(), model.getImage());
                            viewHolder.button.setOnClickListener(new View.OnClickListener() {
                                @Override
                                public void onClick(View view) {
                                    Toast.makeText(view.getContext(), "esto es un boton"+ view.getNextFocusUpId(), Toast.LENGTH_SHORT).show();
    
                                }
                            });
                        }
                    };
            mBlogList.setAdapter(firebaseRecyclerAdapter);
        }
        //View Holder For Recycler View
        public static class BlogViewHolder extends RecyclerView.ViewHolder  {
            View mView;
            Button button ;
    
            public BlogViewHolder(View itemView) {
    
                super(itemView);
               button = (Button)mView.findViewById(R.id.share);
    
    
    
    
    
                mView= itemView;
    
                itemView.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        // click en la imagen hace algo
                        //añadir luego
                        Toast.makeText(v.getContext(), "hola", Toast.LENGTH_SHORT).show();
    
                    }
                });
    
            }
            public void setTitle(String title){
                TextView post_title = (TextView)mView.findViewById(R.id.titleText);
                post_title.setText(title);
            }
            public void setImage(Context ctx , String image){
                ImageView post_image = (ImageView)mView.findViewById(R.id.imageViewy);
                // We Need TO pass Context
                Picasso.with(ctx).load(image).into(post_image);
            }    }}