StaggerredRecyclerAdapter

[dofreelancer19]

Hi
I have issue in my code i need help on below code : (img)
package com.abdbarham.wallpaperpro02;

import android.content.Context;
import android.support.annotation.NonNull;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageSwitcher;
import android.widget.ImageView;

import java.util.List;

public class StaggerredRecyclerAdapter extends RecyclerView.Adapter<StaggerredRecyclerAdapter.ImageViewHolder> {

Context mContext;
List<row> mdata;


public StaggerredRecyclerAdapter(Context mContext, List<row> mdata) {
    this.mContext = mContext;
    this.mdata = mdata;
}

@NonNull
@Override
public ImageViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {

    View view = LayoutInflater.from(mContext).inflate(R.layout.row_item, viewGroup, false);

    return new ImageViewHolder(view);
}

@Override
public void onBindViewHolder(@NonNull ImageViewHolder imageViewHoder, int i) {

    // bind image here
    ImageViewHolder.img.setImageResource(mdata.get(i).getImg());

}

@Override
public int getItemCount() {
    return mdata.size();
}


public class ImageViewHolder extends RecyclerView.ViewHolder {

    ImageView img;




public ImageViewHolder(@NonNull View itemView) {
    super(itemView);
    img = itemView.findViewById(R.id.row_img);




}

}

}

[dofreelancer19]

in the main_activity i see issue on (uper();) , see the below code:
package com.abdbarham.wallpaperpro02;

import android.net.wifi.aware.WifiAwareManager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.StaggeredGridLayoutManager;
import android.view.Window;
import android.view.WindowManager;

import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity {

private RecyclerView staggeredfv;
private StaggerredRecyclerAdapter adapter ;
private StaggerredGridLayoutManager manager;


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    requestWindowFeature(Window.FEATURE_NO_TITLE);
    getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,WindowManager.LayoutParams.FLAG_FULLSCREEN);



    setContentView(R.layout.activity_main);


    getSupportActionBar().hide();





    staggeredfv = findViewById(R.id.Staggered_fv);
    manager = new StaggerredGridLayoutManager(2,StaggeredGridLayoutManager.VERTICAL);
    staggeredfv.setLayoutManager(manager);
    // lets create a simple array list of images

    List<row> lst = new ArrayList<>();
    lst.add(new row(R.drawable.a1));
    lst.add(new row(R.drawable.a2));
    lst.add(new row(R.drawable.a3));
    lst.add(new row(R.drawable.a4));
    lst.add(new row(R.drawable.a5));
    lst.add(new row(R.drawable.a6));

    adapter = new StaggeredRecyclerAdapter(this,lst);
    staggeredfv.setAdapter (adapter);






}

private class StaggerredGridLayoutManager extends RecyclerView.LayoutManager {
    public StaggerredGridLayoutManager(int i, int vertical) {
    }

    @Override
    public RecyclerView.LayoutParams generateDefaultLayoutParams() {
        return null;
    }
}

private class StaggeredRecyclerAdapter extends StaggerredRecyclerAdapter {
    public StaggeredRecyclerAdapter(MainActivity mainActivity, List<row> lst) {
        super();
    }
}

}