究竟是什么标识了网站访问者？

Question

Heaven

Asked:2020-01-25 15:50:19 +0000 UTC2020-01-25 15:50:19 +0000 UTC 2020-01-25 15:50:19 +0000 UTC

适配器 RecyclerView

772

帮助聊天适配器。

Apadter 现在看起来像这样：

public class MSGAdapter extends RecyclerView.Adapter<MSGAdapter.MSGViewHolder> {

ArrayList<MessageModel> messages;

public MSGAdapter(ArrayList<MessageModel> messages) {
    this.messages = messages;
}

@Override
public MSGViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.msg_card_layout, parent, false);
    MSGAdapter.MSGViewHolder nh = new MSGAdapter.MSGViewHolder(v);
    return nh;
}

@Override
public void onBindViewHolder(MSGViewHolder holder, int position) {
       Context ctx = holder.itemView.getContext();
       LinearLayout.LayoutParams lparamsFile = new LinearLayout.LayoutParams(150, 150);
        holder.message_.setText(messages.get(position).getContent().toString()); // Добавление текста сообщения
        if(messages.get(position).getFile() != null) {
            for (int i = 0; i < messages.get(position).getFile().size(); i++) {
                ImageView file = new ImageView(ctx);//Изображение вложения
                file.setScaleType(ImageView.ScaleType.CENTER_CROP);
                file.setLayoutParams(lparamsFile);
                switch (messages.get(position).getFile().get(i).getType().toString()) {
                    case "img":
                        Glide.with(ctx).load(messages.get(position).getFile().get(i).getSrc()).into(file);
                        break;
                    case "doc":
                        file.setImageDrawable(ctx.getResources().getDrawable(R.drawable.doc));
                        break;
                    case "audio":
                        file.setImageDrawable(ctx.getResources().getDrawable(R.drawable.audio));
                        break;
                    case "video":
                        file.setImageDrawable(ctx.getResources().getDrawable(R.drawable.video));
                        break;
                }

                holder.fileLayout.addView(file);
            }
        }
}


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

public static class MSGViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener{

    CardView cv;
    LinearLayout mainLayout, messageLayout, fileLayout;
    TextView message_;
    public MSGViewHolder(View itemView) {
        super(itemView);
        cv = (CardView) itemView.findViewById(R.id.msg_card);

        mainLayout = (LinearLayout) itemView.findViewById(R.id.main_layout);
        messageLayout = (LinearLayout) itemView.findViewById(R.id.message_layout);
        fileLayout = (LinearLayout) itemView.findViewById(R.id.file_layout);
        message_ = (TextView) itemView.findViewById(R.id.message);
    }

    @Override
    public void onClick(View view) {
    }
}

消息（和附件）正常显示，只有在滚动消息列表时，附件才会“混乱”。

我已经明白这是因为我在中声明了消息附件 ( ImageView ) OnBindViewHolder，如果我事先不知道消息中会有多少附件，我如何将它“传输”到 OnCreateViewHolder 阶段？messages.get(position).getFile()我需要在发送消息时从数组 ( ) 中获取它们（附件）

3 个回答

Voted

Николай Конорев · Answer 1 · 2020-01-28T02:06:33Z

持有人在 recyclerview 中重复使用。我建议您在每次绑定之前“重置”持有人。在您的情况下，我建议在 holder 字段中保留指向 ImageView 的链接，并在绑定之前清除它。而且 TextView 中的文字也不会多此一举，一目了然。

public class MSGAdapter extends RecyclerView.Adapter<MSGAdapter.MSGViewHolder> {

ArrayList<MessageModel> messages;

public MSGAdapter(ArrayList<MessageModel> messages) {
this.messages = messages;
}

@Override
public MSGViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v =     LayoutInflater.from(parent.getContext()).inflate(R.layout.msg_card_layout,     parent, false);
MSGAdapter.MSGViewHolder nh = new MSGAdapter.MSGViewHolder(v);
return nh;
}

@Override
public void onBindViewHolder(MSGViewHolder holder, int position) {
   Context ctx = holder.itemView.getContext();
   LinearLayout.LayoutParams lparamsFile = new      LinearLayout.LayoutParams(150, 150);
   holder.clearImage();
   holder.message_.setText("");
    holder.message_.setText(messages.get(position).getContent().toString());     // Добавление текста сообщения
        if(messages.get(position).getFile() != null) {
        for (int i = 0; i < messages.get(position).getFile().size(); i++) {
            ImageView file = new ImageView(ctx);//Изображение вложения
            file.setScaleType(ImageView.ScaleType.CENTER_CROP);
            file.setLayoutParams(lparamsFile);
            switch     (messages.get(position).getFile().get(i).getType().toString()) {
                case "img":
                    Glide.with(ctx).load(messages.get(position).getFile().get(i).getSrc()).into(file);
                    break;
                case "doc":
                    file.setImageDrawable(ctx.getResources().getDrawable(R.drawable.doc));
                    break;
                case "audio":
                    file.setImageDrawable(ctx.getResources().getDrawable(R.drawable.audio));
                    break;
                case "video":
                    file.setImageDrawable(ctx.getResources().getDrawable(R.drawable.video));
                    break;
            }

            holder.addImage(file);
        }
    }
}


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

public static class MSGViewHolder extends RecyclerView.ViewHolder implements     View.OnClickListener{
ImageView file;
CardView cv;
LinearLayout mainLayout, messageLayout, fileLayout;
TextView message_;
public MSGViewHolder(View itemView) {
    super(itemView);
    cv = (CardView) itemView.findViewById(R.id.msg_card);

    mainLayout = (LinearLayout) itemView.findViewById(R.id.main_layout);
    messageLayout = (LinearLayout) itemView.findViewById(R.id.message_layout);
    fileLayout = (LinearLayout) itemView.findViewById(R.id.file_layout);
    message_ = (TextView) itemView.findViewById(R.id.message);
}

@Override
public void onClick(View view) {
}

public void addImage(ImageView file){
    this.file = file;
    fileLayout.addView(file);
}
public void clearImage(){
    if (file!=null){
        fileLayout.removeView(file);
        file = null;
    }
}
}

Iman · Answer 2 · 2020-01-25T21:45:37Z

尝试这样做：

@Override
public void onBindViewHolder(MSGViewHolder holder, int position) {
       Context ctx = holder.itemView.getContext();
       LinearLayout.LayoutParams lparamsFile = new LinearLayout.LayoutParams(150, 150);
        holder.message_.setText(messages.get(position).getContent().toString()); // Добавление текста сообщения
        holder.message_.setTag(position);
        if(messages.get(Integer.parseInt(String.valueOf(holder.message_.getTag()))).getFile() != null) {
            for (int i = 0; i < messages.get(Integer.parseInt(String.valueOf(holder.message_.getTag()))).getFile().size(); i++) {
                ImageView file = new ImageView(ctx);//Изображение вложения
                file.setScaleType(ImageView.ScaleType.CENTER_CROP);
                file.setLayoutParams(lparamsFile);
                switch (messages.get(Integer.parseInt(String.valueOf(holder.message_.getTag()))).getFile().get(i).getType().toString()) {
                    case "img":
                        Glide.with(ctx).load(messages.get(Integer.parseInt(String.valueOf(holder.message_.getTag()))).getFile().get(i).getSrc()).into(file);
                        break;
                    case "doc":
                        file.setImageDrawable(ctx.getResources().getDrawable(R.drawable.doc));
                        break;
                    case "audio":
                        file.setImageDrawable(ctx.getResources().getDrawable(R.drawable.audio));
                        break;
                    case "video":
                        file.setImageDrawable(ctx.getResources().getDrawable(R.drawable.video));
                        break;
                }

                holder.fileLayout.addView(file);
            }
        }
}

Юрий Чорный · Answer 3 · 2020-01-28T00:04:18Z

Юрий Чорный

2020-01-28T00:04:18Z2020-01-28T00:04:18Z

如果没有附件，imageview 不会改变。并且有些情况下会加载旧的。他不在的时候有事可做

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