Question

我知道有很多类似的问题，但我无法找到我犯的错误，如果有人可以提供帮助的话。我试图在数组列表中显示值，如聊天格式，但数组列表项在滚动时被放错了

 @Override
        public View getView(int position, View convertView, ViewGroup parent) {

            final ViewHolder holder;
            if (convertView == null) {

                convertView = LayoutInflater.from(getActivity()).inflate(
                        R.layout.chat_row, parent, false);
                holder = new ViewHolder();
     holder.messageLeft = (TextView) convertView
                    .findViewById(R.id.leftBox);
            holder.messageRight = (TextView) convertView
                    .findViewById(R.id.rightBox);
      convertView.setTag(holder);

            } else {
                holder = (ViewHolder) convertView.getTag();
            }

            try { if (snd_id.get(position).equalsIgnoreCase(appPref.getData("Uid"))) {
                holder.messageLeft.setText(snd_name.get(position)+":"+"\n"+chat.get(position));
                holder.messageLeft.setVisibility(View.VISIBLE);
                holder.messageRight.setVisibility(View.GONE);
            } else {
                holder.messageRight.setText(snd_name.get(position)+":"+"\n"+chat.get(position));
                holder.messageRight.setVisibility(View.VISIBLE);
                holder.messageLeft.setVisibility(View.GONE);
            }
            } catch (Exception e) {
                e.printStackTrace();
            }

            return convertView;

        }

这是视图持有者类

private static class ViewHolder {
        public TextView messageLeft;
        public TextView messageRight;
    }

Answer 1

只需在holder.messageRight.setVisibility(View.GONE);声明中加入holder.messageLeft.setVisibility(View.GONE);和if-else。

 try {
        if (snd_id.get(position).equalsIgnoreCase(appPref.getData("Uid"))) {
            holder.messageLeft.setText(snd_name.get(position)+":"+"\n"+chat.get(position));
            holder.messageLeft.setVisibility(View.VISIBLE);
            holder.messageRight.setVisibility(View.GONE);
        } else {
            holder.messageRight.setText(snd_name.get(position)+":"+"\n"+chat.get(position));
            holder.messageRight.setVisibility(View.VISIBLE);
            holder.messageLeft.setVisibility(View.GONE);
        }

让我知道它是否适合你。

Answer 2

您每次都会findViewById ViewHolder。if-else的设计不是这样的。请改变您的if (convertView == null) { convertView = LayoutInflater.from(getActivity()).inflate( R.layout.chat_row, parent, false); holder = new ViewHolder(); holder.messageLeft = (TextView) convertView .findViewById(R.id.leftBox); holder.messageRight = (TextView) convertView .findViewById(R.id.rightBox); convertView.setTag(holder); } else { holder = (ViewHolder) convertView.getTag(); }条件并尝试..

 convertView.setTag(holder);

并删除

{{1}}

在底部

Answer 3

 @Override
    public View getView(int position, View convertView, ViewGroup parent) {

        final ViewHolder holder;
        if (convertView == null) {

            convertView = LayoutInflater.from(getActivity()).inflate(
                    R.layout.chat_row, parent, false);
            holder = new ViewHolder();
 holder.messageLeft = (TextView) convertView
                .findViewById(R.id.leftBox);
        holder.messageRight = (TextView) convertView
                .findViewById(R.id.rightBox);
  convertView.setTag(holder);

        } else {
            holder = (ViewHolder) convertView.getTag();
        }

        try {
            if (snd_id.get(position).equalsIgnoreCase(appPref.getData("Uid"))) {
                holder.messageLeft.setText(snd_name.get(position)+":"+"\n"+chat.get(position));
                holder.messageLeft.setVisibility(View.VISIBLE);
            } else {
                holder.messageRight.setText(snd_name.get(position)+":"+"\n"+chat.get(position));
                holder.messageRight.setVisibility(View.VISIBLE);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }

        return convertView;

    }

这是使用视图的有效和正确的方法

查看持有人和自定义列表视图项目在滚动时被洗牌

3 个答案: