我有一个聊天屏幕，我可以在其中与其他用户聊天，我正在将聊天数据(消息、时间和发件人通过列表)发送到 RecyclerAdapter，后者用数据填充聊天 View 。现在我有一个列表，其中包含不同的数据布局。像这样

这是我将第二个 arraylist 调用到 RecyclerAdapter 的方法

public void TransferResultTo_Activity(List<Image_data_Wrapper> list) {
        Log.d(TAG,"Here is data Result From AsyncTask "+list.size());
        getResult=list;
        Image_data_Wrapper Image=getResult.get(0);
        Log.d(TAG,"Result from Image data "+Image.getPage_Title());
        adapter=new Chat_Adapter(this,message,getResult);
        adapter.notifyDataSetChanged();
    }

如上述方法，当我尝试通过 recyclerView.setAdapter(adapter); 调用适配器时，它会从屏幕上删除所有消息并显示我的图像数据。但我想保留所有消息并通过新列表显示带有数据的图像

这是我的聊天适配器

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

    private String UserID;
    private Context context;
    //TAG FOR TRACKING SELF MESSAGE
    private int Self_Msg=0;
    //ARRAYLIST OF MESSAGES OBJECT CONTAINING ALL THE MESSAGES IN THE THREAD
    private List<Chat_Wrapper> arrayList_message;
    public static final String TAG="###CHAT_ADAPTER###";
    private List<Image_data_Wrapper> data_Result;
    boolean valtype;


    public Chat_Adapter(Context context, List<Chat_Wrapper> message) {
        //UserID = userID;
        this.context = context;
        this.arrayList_message = message;
        Log.d(TAG,"Chat Adapter Calling");
    }
    public Chat_Adapter(Context context, List<Image_data_Wrapper> result,boolean val) {
        this.context = context;
        this.data_Result = result;
        this.valtype=val;
        Log.d(TAG,"Image data Chat Adapter Calling");
    }

    public Chat_Adapter() {
    }


    @Override
    public Chat_Adapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View itemView;
        Log.d(TAG,"On Create View Holder Calling ");
        if (viewType==Self_Msg){
            itemView= LayoutInflater.from(parent.getContext()).inflate(R.layout.chat_screen_message_item,parent,false);
            Log.d(TAG,"On Create View Holder Calling View Type is "+itemView);
        }

        else if (valtype==true){
            itemView= LayoutInflater.from(parent.getContext()).inflate(R.layout.Image_data_layout,parent,false);
            Log.d(TAG,"ON CREATE VIEW HOLDER RUNNING AND data RESULT VIEW TYPE IS RUNNING "+viewType);
        }

        else {
            itemView= LayoutInflater.from(parent.getContext()).inflate(R.layout.chat_screen_message_item,parent,false);
            Log.d(TAG,"On Create View Holder Calling View Type is "+itemView);
        }
        return new ViewHolder(itemView);
    }

    @Override
    public void onBindViewHolder(Chat_Adapter.ViewHolder holder, int position) {
        if (valtype==true){
            Image_data_Wrapper wrapper=data_Result.get(position);
            holder.data_title.setText(wrapper.getPage_Title());
            holder.data_link.setText(wrapper.getPage_Link());
            holder.data_snippet.setText(wrapper.getPage_Desc());
            Picasso.with(context).load(wrapper.getPage_ImageThumb()).into(holder.Image_Image);
            valtype=false;

        }
        else {

            Log.d(TAG,"On Bind VIew Holder Context "+context);
            Chat_Wrapper wrapper=arrayList_message.get(position);
            Log.d(TAG,"On Bind VIew Holder Chat Wrapper "+wrapper);
            holder.Message.setText(wrapper.getMessage());
            holder.TimeStamp.setText(wrapper.getTimestamp());

        }



    }

    @Override
    public int getItemCount() {
        Log.d(TAG,"Get Item Count Running");
        int items;
        if (valtype==true){
            Log.d(TAG,"data Result Array is not empty");
            items=data_Result.size();
            Log.d(TAG,"Total Number Of Item "+items);
            return items;
        }
        else {
            Log.d(TAG,"ARRAY SIZE AT GETITEM COUNT "+arrayList_message.size());
            return arrayList_message.size();
        }





    }


    @Override
    public int getItemViewType(int position) {
        Log.d(TAG,"Get Item View Type Running");
        return position;
    }

    public class ViewHolder extends RecyclerView.ViewHolder {
        TextView Message,TimeStamp,data_title,data_link,data_snippet;
        ImageView User_image,Image_Image;
        ImageButton data_SendButton;


         public ViewHolder(View itemView) {
             super(itemView);
             Message= (TextView) itemView.findViewById(R.id.Single_Item_Chat_Message);
             TimeStamp= (TextView) itemView.findViewById(R.id.Single_Item_Chat_TimeStamp);
             User_image= (ImageView) itemView.findViewById(R.id.Single_Item_Chat_ImageView);

             if (valtype==true){
                 Log.d(TAG,"Setting View For Image data ");
                 data_title= (TextView) itemView.findViewById(R.id.Image_data_Title);
                 data_link= (TextView) itemView.findViewById(R.id.Image_data_Link);
                 data_snippet= (TextView) itemView.findViewById(R.id.Image_data_Snippet);

                 Image_Image= (ImageView) itemView.findViewById(R.id.Image_data_Image);
                 data_SendButton= (ImageButton) itemView.findViewById(R.id.Image_data_SendButton);
             }




        }
    }

    public void updateDataWithdataResult(List<Image_data_Wrapper> list,boolean setValue){
        Log.d(TAG,"Update Data Method Calling");
        this.data_Result=list;
        this.valtype=setValue;
    }
}

这段代码我遇到的问题

• 随着 notifiydatasetchanged 只有 Adapter 构造函数在调用(正确的一个)但从不调用 getItemCount()
• 发送带有数据的 boolean 值是否是正确的检查方法，如果仅从 ImageArrayList 调用然后输入其相关数据或 View ？
• 将两个 List 放入具有自己布局的单个 RecyclerView 的最佳方法是什么

更新:当我通过 recyclerView.setAdapter(adapter) 调用适配器时，它按我想要的方式工作，但 adapter.notifyDataSetChanged 使调用卡在适配器构造函数(感谢 DanielLaneDC)。那么我可以就这样保留它吗，或者 adapter.notifyDataSetChanged 应该可以工作？

最佳答案

听起来您想使用同一个 RecyclerView.Adapter 在同一个 RecyclerView 中显示两个不同的项目列表。值得庆幸的是，RecyclerView.Adapter 可以很好地处理这种事情。

RecyclerView.Adapter 应该是这样的:

public class ChatAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
    final int VIEW_TYPE_MESSAGE = 0;
    final int VIEW_TYPE_IMAGE = 1;

    Context context;
    List<ChatWrapper> messages;
    List<ImageDataWrapper> images;

    public ChatAdapter(Context context, List<ChatWrapper> messages, List<ImageDataWrapper> images){
        this.context = context;
        this.messages = messages;
        this.images = images;
    }

    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType){
        if(viewType == VIEW_TYPE_MESSAGE){
            return new MessageViewHolder(itemView);
        }

        if(viewType == VIEW_TYPE_IMAGE){
            return new ImageViewHolder(itemView);
        }

        return null;
    }

    @Override
    public void onBindViewHolder(RecyclerView.ViewHolder viewHolder, int position){
        if(viewHolder instanceof MessageViewHolder){
            ((MessageViewHolder) viewHolder).populate(messages.get(position));
        }

        if(viewHolder instanceof ImageViewHolder){
            ((ImageViewHolder) viewHolder).populate(images.get(position - messages.size()));
        }
    }

    @Override
    public int getItemCount(){
        return messages.size() + images.size();
    }

    @Override
    public int getItemViewType(int position){
        if(position < messages.size()){
            return VIEW_TYPE_MESSAGE;
        }

        if(position - messages.size() < images.size()){
            return VIEW_TYPE_IMAGE;
        }

        return -1;
    }

    public class MessageViewHolder extends RecyclerView.ViewHolder {
        TextView message;
        TextView timeStamp;
        ImageView userImage;

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

            message = (TextView) itemView.findViewById(R.id.Single_Item_Chat_Message);
            timeStamp = (TextView) itemView.findViewById(R.id.Single_Item_Chat_TimeStamp);
            userImage = (ImageView) itemView.findViewById(R.id.Single_Item_Chat_ImageView);
        }

        public void populate(ChatWrapper chatWrapper){
            message.setText(chatWrapper.getMessage());
            userImage.setText(chatWrapper.getTimestamp());
        }
    }

    public class ImageViewHolder extends RecyclerView.ViewHolder {
        TextView dataTitle;
        TextView dataLink;
        TextView dataSnippet;
        ImageView image;
        ImageButton dataSendButton;

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

            dataTitle = (TextView) itemView.findViewById(R.id.Image_data_Title);
            dataLink = (TextView) itemView.findViewById(R.id.Image_data_Link);
            dataSnippet = (TextView) itemView.findViewById(R.id.Image_data_Snippet);
            image = (ImageView) itemView.findViewById(R.id.Image_data_Image);
            dataSendButton = (ImageButton) itemView.findViewById(R.id.Image_data_SendButton);
        }

        public void populate(ImageDataWrapper imageDataWrapper){
            dataTitle.setText(imageDataWrapper.getPage_Title());
            dataLink.setText(imageDataWrapper.getPage_Link());
            dataSnippet.setText(imageDataWrapper.getPage_Desc());
            Picasso.with(context).load(imageDataWrapper.getPage_ImageThumb()).into(image);
        }
    }
}

这是您的 Activity 需要的:

List<ChatWrapper> messages;
List<ImageDataWrapper> images;
ChatAdapter adapter;

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

    messages = new ArrayList<>();
    images = new ArrayList<>();
    ChatAdapter adapter = new ChatAdapter(this, messages, images);

    RecyclerView recyclerView = (RecyclerView) findViewById(R.id.recycler_view);
    recyclerView.setLayoutManager(new LinearLayoutManager(this));
    recyclerView.setAdapter(adapter);
}

public void addMessage(ChatWrapper message){
    messages.add(message);
    adapter.notifyDataSetChanged();
}

public void removeMessage(ChatWrapper message){
    if(messages.remove(message)){
        adapter.notifyDataSetChanged();
    }
}

public void addImage(ImageDataWrapper image){
    images.add(image);
    adapter.notifyDataSetChanged();
}

public void removeImage(ImageDataWrapper image){
    if(images.remove(image)){
        adapter.notifyDataSetChanged();
    }
}

当你想更新数据时，只需调用 addMessage(ChatWrapper) 或 removeMessage(ChatWrapper) 和 addImage(ImageDataWrapper)或 removeImage(ImageDataWrapper) 用于图像。

一些关键点:

• 您不想创建任何新的适配器或列表，您只想调用我们现有对象的方法。
• 你的适配器应该表现得好像它总是必须处理消息和图像，但只是它可以处理 0 条消息或 0 条图像(没有 valType 变量，getItemCount() 应始终返回两个列表的总大小等)

关于java - 两个ArrayList 一个RecyclerView Adapter，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/42450466/