在滚动Listview时查看可见性问题

时间:2015-02-18 21:15:03

标签: android listview android-listview android-scrollbar

我有一个带有textview和imageview的自定义列表视图,以及像checkmark一样的imageview。在选择textview时,在Listview的OnItemClickListener上,我将使imageview Visibilty可见,以显示已选中。

 stickyList.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE);
                stickyList.setOnItemClickListener(new OnItemClickListener() {

                    @Override
                    public void onItemClick(AdapterView<?> parent, View view,
                            int position, long id) {
                        // TODO Auto-generated method stub
                        String tag = (String) ((TextView) view
                                .findViewById(R.id.tvtag)).getText();
                         ImageView cb = (ImageView)
                         view.findViewById(R.id.ic_check);
                        if (cb.getVisibility() == View.VISIBLE) {
                            cb.setVisibility(
                                    View.GONE);

                            selectedtags.remove(tag);
                        } else {
                            cb.setVisibility(
                                    View.VISIBLE);
                            selectedtags.add(tag);
                        }
                    }
                });

它工作正常,直到Listview滚动。如果我选择了listview的前两个postions textview,当我向下滚动listview时,imageview(cb)的可见性对于前两个位置是可见的。这意味着在滚动后,imageview在相同位置可见。

GetviewMethod:

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    // TODO Auto-generated method stub
    ViewHolder holder;
    if (convertView == null) {
        holder = new ViewHolder();
        convertView = mInflater.inflate(R.layout.recenttag_list_item,
                parent, false);
        holder.text = (TextView) convertView.findViewById(R.id.tvtag);
        holder.checkmark = (ImageView) convertView
                .findViewById(R.id.ic_check);
        convertView.setTag(holder);
    } else {
        holder = (ViewHolder) convertView.getTag();
    }
    holder.text.setText(data.get(position).mytag);
    return convertView;
}

1 个答案:

答案 0 :(得分:4)

您看到的原因是因为列表项视图被回收(这是convertView的用途)。当您滚动ListView时,滚动屏幕的上一个项目将作为下一个位置的convertView传回适配器。

您需要确保在每次调用getView()时完全重置项目视图的状态,以便这样的更改不会从一次使用视图项目泄漏到下一次。这可能意味着您必须始终检查getView()中该位置的当前“已检查”值,以确定它是否应该可见。

编辑:也许这会有所帮助...

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

    ViewHolder holder;

    /* Unchanged code omitted */

    holder.text.setText(data.get(position).mytag);

    boolean checkVisible = ???; //Use whatever logic your app has to determine if this position should be checked
    holder.checkmark.setVisibility(checkVisible);  //Always set the visibility to what it should be for this position

    return convertView;
}