无法使用recycleView在自定义cardviewadapter中更改字体/添加背景颜色到textView

Question

我已经实施了cardview以及recycleview。我有一个自定义适配器，现在我想更改字体。我尝试使用：

private Typeface custom_font = Typeface.createFromAsset(context.getAssets(), "fonts/VarelaRound-Regular.ttf");

但是它给出了错误跟踪错误：

java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.res.AssetManager android.content.Context.getAssets()' on a null object reference

当我尝试将背景颜色设置为文本视图时也出现错误

holder.count.setBackgroundColor(context.getResources().getColor(R.color.software_color));

我已将自定义适配器代码附加到

下面

public class CardViewAdapter extends RecyclerView.Adapter<CardViewAdapter.MyViewHolder> {

private ArrayList<CardViewData> cardViewDataSet;
public Resources res;

public static class MyViewHolder extends RecyclerView.ViewHolder {
    protected TextView title;
    protected TextView count;

    public MyViewHolder(View itemView) {
        super(itemView);

        this.title = (TextView) itemView.findViewById(R.id.title);
        this.count = (TextView) itemView.findViewById(R.id.count);
    }
}

public CardViewAdapter(ArrayList<CardViewData> cardviewdata) {
    this.cardViewDataSet = cardviewdata;
}

@Override
public MyViewHolder onCreateViewHolder(ViewGroup parent,
                                       int viewType) {
    View view = LayoutInflater.from(parent.getContext())
            .inflate(R.layout.card_layout, parent, false);

   // view.setOnClickListener(MainActivity.myOnClickListener);

    MyViewHolder myViewHolder = new MyViewHolder(view);
    return myViewHolder;
}

@Override
public void onBindViewHolder(final MyViewHolder holder, final int listPosition) {

    Typeface custom_font = Typeface.createFromAsset(context.getAssets(), "fonts/VarelaRound-Regular.ttf");
    holder.title.setText((String)cardViewDataSet.get(listPosition).getTitle());
            holder.count.setText(String.valueOf(cardViewDataSet.get(listPosition).geCount()));

    holder.title.setTypeface(custom_font);
    holder.count.setTypeface(custom_font);

    holder.count.setBackgroundColor(context.getResources().getColor(R.color.software_color));

}

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

}