glide does not show anything in recyclerView adapter

I have got an activity with recyclerView. This recyclerview contains images. but glide does not show anything. just black square. i tried to load images from internet by URL and from sd-card.

public class MyRecyclerViewAdapter extends RecyclerView.Adapter<MyRecyclerViewAdapter.MyViewHolder> {
private ArrayList<Integer> list;
private Context context;

public MyRecyclerViewAdapter(ArrayList<Integer> list, MainActivity context) {
    this.list = list;
    this.context = context.getApplicationContext();
}

public static class MyViewHolder extends RecyclerView.ViewHolder {
    ImageView photo;

    public MyViewHolder(View itemView) {
        super(itemView);
        photo = (ImageView) itemView.findViewById(R.id.photo);
    }
}

@Override
public MyViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {
    View v = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.item_for_recycler_view, viewGroup, false);
    MyViewHolder myViewHolder = new MyViewHolder(v);
    return myViewHolder;
}

@Override
public void onBindViewHolder(MyViewHolder viewHolder, int i) {
//        viewHolder.photo.setImageResource(list.get(i));
    ImageView imageView = viewHolder.photo;
    Glide.with(context).load(list.get(i)).into(imageView);
}

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

}