在我的 ExpandableListView 中,我希望每个组的第一个子项与组中的其他子项具有不同的 xml 视图。
我想要实现的目标是这样的:
我设法使用以下代码来做到这一点:
public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View newView, ViewGroup parent) {
if (newView==null){
// CHILD HEADER
if (childPosition == 0){
LayoutInflater infalInflater = (LayoutInflater) this.context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
newView = infalInflater.inflate(R.layout.super_trener_cell_child_header, null);
// CHILD CELL
else{
LayoutInflater infalInflater = (LayoutInflater) this.context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
newView = infalInflater.inflate(R.layout.super_trener_cell_child, null);
}
}
return newView;
}
效果很好。 然而,有一个问题......每当我扩展和收缩单元格时,我都会得到子单元格的另一种出现顺序。
以下是一些屏幕截图,显示了正在发生的情况(数字代表它们应该出现的顺序):
每次点击组标题后,单元格反转的原因可能是什么?
编辑: 整个适配器代码:
公共类 SuperTrenerCellAdapter 扩展 BaseExpandableListAdapter {
Context context;
List<SuperTrenerTopic> topics = new LinkedList<SuperTrenerTopic>();
private static LayoutInflater inflater = null;
public SuperTrenerCellAdapter(List<SuperTrenerTopic> topics, Context context) {
this.topics = topics;
this.context = context;
}
@Override
public int getGroupCount() {
return topics.size();
}
@Override
public int getChildrenCount(int groupPosition) {
SuperTrenerTopic topic = topics.get(groupPosition);
return topic.getLessonList().size()+1;
}
@Override
public Object getGroup(int groupPosition) {
return topics.get(groupPosition);
}
@Override
public Object getChild(int groupPosition, int childPosition) {
return childPosition;
}
@Override
public long getGroupId(int groupPosition) {
return groupPosition;
}
@Override
public long getChildId(int groupPosition, int childPosition) {
return childPosition;
}
@Override
public boolean hasStableIds() {
return false;
}
@Override
public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {
if (convertView == null) {
LayoutInflater infalInflater = (LayoutInflater) this.context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = infalInflater.inflate(R.layout.super_trener_cell_header, null);
}
SuperTrenerTopic topic = topics.get(groupPosition);
TextView topicTitle = (TextView)convertView.findViewById(R.id.stc_topicName);
topicTitle.setText(topic.getName());
return convertView;
}
@Override
public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView, ViewGroup parent) {
SuperTrenerTopic topic = topics.get(groupPosition);
if (convertView==null){
// CHILD HEADER
if (childPosition == 0){
LayoutInflater infalInflater = (LayoutInflater) this.context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = infalInflater.inflate(R.layout.super_trener_cell_child_header, null);
}
// LESSON CELL
else{
LayoutInflater infalInflater = (LayoutInflater) this.context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = infalInflater.inflate(R.layout.super_trener_cell_child, null);
SuperTrenerLesson stl = topic.getLessonList().get(childPosition-1);
TextView title = (TextView)convertView.findViewById(R.id.st_cell_child_title);
title.setText(""+stl.getTitle());
}
}
return convertView;
}
@Override
public boolean isChildSelectable(int groupPosition, int childPosition) {
if (childPosition == 0){
return false;
}
else{
return true;
}
}
}
问题是你在getChildView中的convertView。注释掉一分钟的convertView null 检查,以便您可以看到发生了什么。
让它看起来像这样:
@Override
public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView, ViewGroup parent) {
SuperTrenerTopic topic = topics.get(groupPosition);
//if (convertView==null)
{
// CHILD HEADER
if (childPosition == 0){
LayoutInflater infalInflater = (LayoutInflater) this.context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = infalInflater.inflate(R.layout.super_trener_cell_child_header, null);
}
// LESSON CELL
else{
LayoutInflater infalInflater = (LayoutInflater) this.context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = infalInflater.inflate(R.layout.super_trener_cell_child, null);
SuperTrenerLesson stl = topic.getLessonList().get(childPosition-1);
TextView title = (TextView)convertView.findViewById(R.id.st_cell_child_title);
title.setText(""+stl.getTitle());
}
}
return convertView;
}
当您打开和关闭标题时,它会回收视图,因此convertView可能不会返回为空,因此它使用存储的旧数据。您没有使用回收视图(convertView)设置任何新内容。您需要更改条件以适应 childView 实际回收的情况(即,convertView 不会为 null 时)。
我经历了同样的错误操作(在片段、3级可扩展列表视图中)。在GetChildView中用双斜杠注释convertibleView调查,该过程运行良好,但它不是CPU有效的解决方案。我不清楚为什么要重新分配使用的子视图(convertView),也许有任何可能的错误。 //如果(convertView==null){ ... // }