无法声明变量

Question

为什么我无法在MessageViewHolder类中声明变量？我想为我的xml文件找到viewById。顺便说一句，我正在最新的64位Ubuntu中运行最新版本的Android Studio。但是，肯定没有版本问题。我尝试了其他一些变量。同样的问题！

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

        return new MessageViewHolder(view);
    }

    @Override
    public void onBindViewHolder(@NonNull MessageViewHolder holder, int position) {
        Messages messages = messagesList.get(position);
        holder.chatText.setText(messages.getMessage());
    }

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

  public class MessageViewHolder extends RecyclerView.ViewHolder {

        public TextView chatText;
        public CircleImageView chatImage;


        public MessageViewHolder(View itemView) {
            super(itemView);
        }

        chatText =
        chatImage
    }

}

Answer 1

在视图持有人中，您从视图中获取ID

就这样-

public MessageViewHolder(View itemView) {
   super(itemView);
   chatText = itemView.findViewById(R.id.*);
   chatImage = itemView.findViewById(R.id.*);
}

Answer 2

您需要在 findViewById 内进行 MessageViewHolder() ，使用itemView

尝试一下

public class MessageViewHolder extends RecyclerView.ViewHolder {

        public TextView chatText;
        public CircleImageView chatImage;


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

          chatText =itemView.findViewById(R.id.chatText);
          chatImage=itemView.findViewById(R.id.chatImage);
        }


    }