如何更改卡片视图的背景颜色？

Question

Cardview一旦它被点击，我试图改变它的背景颜色。这里列出通知历史记录RecyclerView。Cardview颜色只在那个时候改变。如果我返回并再次打开应用程序意味着它不会被更改。我必须做什么？

这是我的适配器类

public class NotificationsAdapter extends RecyclerView.Adapter<NotificationsAdapter.ViewHolder> {

    public static final String TAG = "DataViewHolder";

    private Context context;

    private ArrayList<NotificationsModel> notificationsModelList;

    public NotificationsAdapter(Context context, ArrayList<NotificationsModel> notificationsModelList) {

        this.context = context;

        this.notificationsModelList = notificationsModelList;

    }

    @Override

    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

        View v = LayoutInflater.from(parent.getContext())

                .inflate(R.layout.notification_layout, parent, false);

        Log.d(TAG, "onCreateViewHolder: ");

        return new ViewHolder(v);

    }

    @Override

    public void onBindViewHolder(ViewHolder holder, int position) {

        final NotificationsModel notificationsModel = notificationsModelList.get(position);

        holder.title_news.setText(notificationsModel.getTitle());

        holder.notif_message.setText(notificationsModel.getMessage());

    }

    @Override

    public int getItemCount() {

        return notificationsModelList == null ? 0 : notificationsModelList.size();

    }

    public class ViewHolder extends RecyclerView.ViewHolder {

        TextView notif_message, title_news;

        //Initializing Views

        public ViewHolder(View itemView) {

            super(itemView);

            title_news = (TextView) itemView.findViewById(R.id.title_news);

            notif_message = (TextView) itemView.findViewById(R.id.notif_message);

            CardView cardView = (CardView) itemView.findViewById(R.id.cardViewLayoutNotif);

            itemView.findViewById(R.id.notif_message);

            itemView.setOnClickListener(new View.OnClickListener() {

                }

            });

        }

    }

}

Answer 1

IsColorChanged您可以在您的内部添加标志，notificationsModel并且每当您更改cardview模型中更新标志的颜色时，在您的onBindViewHolder中，您可以添加如下检查：if(IsColorChanged){&nbsp; &nbsp; cardView.setCardBackgroundColor(Color.WHITE);}else{&nbsp; &nbsp; cardView.setCardBackgroundColor(Color.BLACK);// ANY OTHER COLOR}