问题展开多层次ExpandableListView [英] Issue with Expanding Multi-Level ExpandableListView
本文介绍了问题展开多层次ExpandableListView的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我有一个多层次（3级，根 - >父 - >子）包含的孩子，也ExpandableListViews ExpandableListView。 我在填起来没有问题;但是，我要展开特定项目的父级的时候我第一次展示活动（的onCreate）。
我成功地扩大了家长的相关根系项目，但我似乎无法展开父项。给定的侦听器调用，但结果并没有反映在我的多级列表。
活动中，我所说的扩展：
公共类活动{
私人诠释groupToExpand = 4，childToExpand = 3;
保护无效的onCreate（包savedInstance）{
最后ExpandableListView ELV =（ExpandableListView）findViewById（R.id.elv）;
如果（ArrayList的= NULL和放大器;！＆安培;！arrayList.isEmpty（））{
elv.setAdapter（新RootAdapter（这一点，ArrayList的）;
//这个选择正确的组，但不扩大的孩子。
elv.setSelectedChild（groupToExpand，childToExpand，真正的）;
elv.expandGroup（groupToExpand）; //这个工程。
}
}
}
我的根适配器：
公共类RootAdapter扩展BaseExpandableListAdapter {
私人列表＆LT;对象＆GT; ArrayList的;
私人上下文的背景下;
私人LayoutInflater充气;
公共RootAdapter（上下文的背景下，名单，其中，对象和GT;的ArrayList）{
this.context =背景;
this.arrayList = ArrayList的;
this.inflater = LayoutInflater.from（上下文）;
}
@覆盖
公共对象getChild（INT groupPosition，诠释childPosition）{
最终对象的父=（对象）getGroup（groupPosition）;
返回parent.arrayList.get（childPosition）;
}
@覆盖
众长getChildId（INT groupPosition，诠释childPosition）{
返回childPosition;
}
@覆盖
公共查看getChildView（INT groupPosition，INT childPosition，
布尔isLastChild，查看convertView，ViewGroup中父）{
最终的对象O =（对象）getChild（groupPosition，childPosition）;
CustomExpandableListView ELV =（CustomExpandableListView）convertView;
ChildViewHolder持有人;
如果（ELV == NULL）{
持有人=新ChildViewHolder（）;
ELV =新CustomExpandableListView（上下文）;
elv.setGroupIndicator（空）;
elv.setDivider（空）;
elv.setCacheColorHint（Color.parseColor（＃00000000））;
elv.setChildDivider（空）;
elv.setChildIndicator（空）;
elv.setScrollingCacheEnabled（假）;
elv.setAnimationCacheEnabled（假）;
holder.cListView = ELV;
elv.setTag（保持器）;
} 其他 {
支架=（ChildViewHolder）elv.getTag（）;
}
最后ParentAdapter适配器=新ParentAdapter（背景下，O）;
holder.cListView.setAdapter（适配器）;
返回ELV;
}
私有静态类ChildViewHolder {
CustomExpandableListView cListView;
}
@覆盖
公众诠释getChildrenCount（INT groupPosition）{
最终对象的父=（对象）getGroup（groupPosition）;
返回parent.arrayList.size（）;
}
@覆盖
公共对象getGroup（INT groupPosition）{
返回arrayList.get（groupPosition）;
}
@覆盖
公众诠释getGroupCount（）{
返回arrayList.size（）;
}
@覆盖
众长getGroupId（INT groupPosition）{
返回groupPosition;
}
@覆盖
公共查看getGroupView（INT groupPosition，布尔isExpanded，
查看convertView，ViewGroup中父）{
查看布局= convertView;
GroupViewHolder持有人;
最终的对象O =（对象）getGroup（groupPosition）;
如果（布局== NULL）{
布局= inflater.inflate（R.layout.item_to_inflate，父母，假）;
持有人=新GroupViewHolder（）;
holder.title =（TextView中）layout.findViewById（R.id.title）;
holder.image =（ImageView的）layout.findViewById（R.id.image）;
layout.setTag（保持器）;
} 其他 {
支架=（GroupViewHolder）layout.getTag（）;
}
holder.title.setText（o.title.trim（））;
返回布局;
}
@覆盖
公共布尔hasStableIds（）{
返回true;
}
@覆盖
公共布尔isChildSelectable（INT groupPosition，诠释childPosition）{
返回true;
}
私有静态类GroupViewHolder {
TextView的称号;
ImageView的形象;
}
公共类CustomExpandableListView扩展ExpandableListView {
公共CustomExpandableListView（上下文的背景下）{
超（上下文）;
}
@覆盖
保护无效onMeasure（INT widthMeasureSpec，诠释heightMeasureSpec）{
heightMeasureSpec = MeasureSpec.makeMeasureSpec（2000，MeasureSpec.AT_MOST）;
super.onMeasure（widthMeasureSpec，heightMeasureSpec）;
}
}
}
最后我ParentAdapter：
公共类ParentAdapter扩展BaseExpandableListAdapter {
私有对象的孩子;
私人LayoutInflater充气;
公共ParentAdapter（上下文的背景下，对象子）{
this.child =子女;
this.inflater = LayoutInflater.from（上下文）;
}
@覆盖
公共对象getChild（INT groupPosition，诠释childPosition）{
返回child.arrayList.get（childPosition）;
}
@覆盖
众长getChildId（INT groupPosition，诠释childPosition）{
返回childPosition;
}
@覆盖
公共查看getChildView（INT groupPosition，INT childPosition，
布尔isLastChild，查看convertView，ViewGroup中父）{
查看布局= convertView;
最终的对象O =（对象）getChild（0，childPosition）;
ChildViewHolder持有人;
如果（布局== NULL）{
布局= inflater.inflate（R.layout.item_to_inflate，父母，假）;
持有人=新ChildViewHolder（）;
holder.title =（TextView中）layout.findViewById（R.id.title）;
layout.setTag（保持器）;
} 其他 {
支架=（ChildViewHolder）layout.getTag（）;
}
holder.title.setText（o.title.trim（））;
返回布局;
}
@覆盖
公众诠释getChildrenCount（INT groupPosition）{
返回child.arrayList.size（）;
}
@覆盖
公共对象getGroup（INT groupPosition）{
返回的孩子;
}
@覆盖
公众诠释getGroupCount（）{
返回1;
}
@覆盖
众长getGroupId（INT groupPosition）{
返回groupPosition;
}
@覆盖
公共查看getGroupView（INT groupPosition，布尔isExpanded，
查看convertView，ViewGroup中父）{
查看布局= convertView;
GroupViewHolder持有人;
如果（布局== NULL）{
布局= inflater.inflate（R.layout.item_to_inflate，父母，假）;
持有人=新GroupViewHolder（）;
holder.image =（ImageView的）layout.findViewById（R.id.image）;
holder.title =（TextView中）layout.findViewById（R.id.title）;
layout.setTag（保持器）;
} 其他 {
支架=（GroupViewHolder）layout.getTag（）;
}
holder.title.setText（o.title.trim（））;
返回布局;
}
@覆盖
公共布尔hasStableIds（）{
返回true;
}
@覆盖
公共布尔isChildSelectable（INT groupPosition，诠释childPosition）{
返回true;
}
私有静态类GroupViewHolder {
TextView的称号;
ImageView的形象;
}
私有静态类ChildViewHolder {
TextView的称号;
}
}
我不能展开根ExpandableListView中的子名单;你知道，扩大项目在父级别的任何正确的方法是什么？
我试图在RootAdapter的getChildView：
如果（groupToExpand == groupPosition和放大器;＆安培; childToExpand == childPosition）{
elv.expandGroup（childToExpand）;
}
然后在我改变了活动：
如果（ArrayList的= NULL和放大器;！＆安培;！arrayList.isEmpty（））{
RootAdapter适配器=新RootAdapter（这一点，ArrayList的）;
elv.setAdapter（适配器）;
//这个选择正确的组，但不扩大的孩子。
elv.setSelectedChild（groupToExpand，childToExpand，真正的）;
elv.expandGroup（groupToExpand）; //这个工程。
adapter.groupToExpand = groupToExpand;
adapter.childToExpand = childToExpand;
adapter.notifyDataSetChanged（）;
}
这扩展了父级别项目，但是，它所产生的家长重复的项目。我该如何正确地做到这一点？这是正确的方式，但我的适配器坏了，因此产生重复的项目？
我只是找不到我在这里缺少什么？
解决方案我最终使用的计算器中的另一篇文章多层次ExpandableListView适配器
。不幸的是我只是找不到链接了，所以我就发表我的code在这里。
在ExpandableListView适配器的最高水平。
RootAdapter.java：
公共类RootAdapter扩展BaseExpandableListAdapter {
私人对象根;
私人最终LayoutInflater充气;
公共类条目{
公众最终CustExpListview CLS;
公众最终SecondLevelAdapter sadpt;
公共入口（CustExpListview CLS，SecondLevelAdapter sadpt）{
this.cls = CLS;
this.sadpt = sadpt;
}
}
公共入口[lsfirst]
//你可以改变的构造取决于你wan't要使用的监听器上。
公共RootAdapter（上下文的背景下，对象根，ExpandableListView.OnGroupClickListener grpLst，
ExpandableListView.OnChildClickListener childLst，ExpandableListView.OnGroupExpandListener grpExpLst）{
this.root =根;
this.inflater = LayoutInflater.from（上下文）;
lsfirst =新条目[root.children.size（）];
的for（int i = 0; I＆LT; root.children.size（）;我++）{
最后CustExpListview celv =新CustExpListview（上下文）;
SecondLevelAdapter ADP =新SecondLevelAdapter（root.children.get（一））;
celv.setAdapter（ADP）;
celv.setGroupIndicator（空）;
celv.setOnChildClickListener（childLst）;
celv.setOnGroupClickListener（grpLst）;
celv.setOnGroupExpandListener（grpExpLst）;
lsfirst [我] =新条目（celv，ADP）;
}
}
@覆盖
公共对象getChild（INT groupPosition，诠释childPosition）{
返回childPosition;
}
@覆盖
众长getChildId（INT groupPosition，诠释childPosition）{
返回childPosition;
}
@覆盖
公共查看getChildView（INT groupPosition，诠释childPosition，布尔isLastChild，
查看convertView，ViewGroup中父）{
//第二级列表
返回lsfirst [groupPosition] .CLS;
}
@覆盖
公众诠释getChildrenCount（INT groupPosition）{
返回1;
}
@覆盖
公共对象getGroup（INT groupPosition）{
返回root.children.get（groupPosition）;
}
@覆盖
公众诠释getGroupCount（）{
返回root.children.size（）;
}
@覆盖
众长getGroupId（INT groupPosition）{
返回groupPosition;
}
@覆盖
公共查看getGroupView（INT groupPosition，布尔isExpanded，查看convertView，
ViewGroup中父）{
//第一级
查看布局= convertView;
GroupViewHolder持有人;
最终目标项=（对象）getGroup（groupPosition）;
如果（布局== NULL）{
布局= inflater.inflate（R.layout.item_root，父母，假）;
持有人=新GroupViewHolder（）;
holder.title =（TextView中）layout.findViewById（R.id.itemRootTitle）;
layout.setTag（保持器）;
} 其他 {
支架=（GroupViewHolder）layout.getTag（）;
}
holder.title.setText（item.title.trim（））;
返回布局;
}
私有静态类GroupViewHolder {
TextView的称号;
}
@覆盖
公共布尔hasStableIds（）{
返回true;
}
@覆盖
公共布尔isChildSelectable（INT groupPosition，诠释childPosition）{
返回true;
}
}
定制ExpandableListView与溶液项有时不被显示。还有一个解决办法，为抛出：IllegalArgumentException一个已知的bug破坏视图时被调用（由pressing后退按钮本质上）。
CustExpListview.java：
公共类CustExpListview扩展ExpandableListView {
公共CustExpListview（上下文的背景下）{
超（上下文）;
}
保护无效onMeasure（INT widthMeasureSpec，诠释heightMeasureSpec）{
//值（2000）不应该是固定的，计算
//如下：cell_height x root_items_count x root_items_children_count
heightMeasureSpec = MeasureSpec.makeMeasureSpec（2000，MeasureSpec.AT_MOST）;
super.onMeasure（widthMeasureSpec，heightMeasureSpec）;
}
@覆盖
保护无效onDetachedFromWindow（）{
尝试 {
super.onDetachedFromWindow（）;
}赶上（抛出：IllegalArgumentException E）{
// TODO：解决方法对于http：//$c$c.google.com/p/android/issues/detail ID = 22751
}
}
}
最后，code到末级适配器。
公共类SecondLevelAdapter扩展BaseExpandableListAdapter {
公共对象的孩子;
公共SecondLevelAdapter（对象子）{
this.child =子女;
}
@覆盖
公共对象getChild（INT groupPosition，诠释childPosition）{
返回child.children.get（groupPosition）.children.get（childPosition）;
}
@覆盖
众长getChildId（INT groupPosition，诠释childPosition）{
返回childPosition;
}
//第三个层次
@覆盖
公共查看getChildView（INT groupPosition，诠释childPosition，布尔isLastChild，
查看convertView，ViewGroup中父）{
查看布局= convertView;
最终目标项=（对象）getChild（groupPosition，childPosition）;
ChildViewHolder持有人;
如果（布局== NULL）{
布局= inflater.inflate（R.layout.item_child，父母，假）;
持有人=新ChildViewHolder（）;
holder.title =（TextView中）layout.findViewById（R.id.itemChildTitle）;
layout.setTag（保持器）;
} 其他 {
支架=（ChildViewHolder）layout.getTag（）;
}
holder.title.setText（item.title.trim（））;
返回布局;
}
@覆盖
公众诠释getChildrenCount（INT groupPosition）{
返回child.children.get（groupPosition）.children.size（）;
}
@覆盖
公共对象getGroup（INT groupPosition）{
返回child.children.get（groupPosition）;
}
@覆盖
公众诠释getGroupCount（）{
返回child.children.size（）;
}
@覆盖
众长getGroupId（INT groupPosition）{
返回groupPosition;
}
//第二级
@覆盖
公共查看getGroupView（INT groupPosition，布尔isExpanded，查看convertView，
ViewGroup中父）{
查看布局= convertView;
ViewHolder持有人;
最终目标项=（对象）getGroup（groupPosition）;
如果（布局== NULL）{
布局= inflater.inflate（R.layout.item_parent，父母，假）;
持有人=新ViewHolder（）;
holder.title =（TextView中）layout.findViewById（R.id.itemParentTitle）;
layout.setTag（保持器）;
} 其他 {
支架=（ViewHolder）layout.getTag（）;
}
holder.title.setText（item.title.trim（））;
返回布局;
}
@覆盖
公共无效registerDataSetObserver（DataSetObserver观察者）{
super.registerDataSetObserver（观察员）;
}
@覆盖
公共无效unregisterDataSetObserver（DataSetObserver观察者）{
Log.d（SecondLevelAdapter，注销观察者）;
如果（观察者！= NULL）{
super.unregisterDataSetObserver（观察员）;
}
}
@覆盖
公共布尔hasStableIds（）{
返回true;
}
@覆盖
公共布尔isChildSelectable（INT groupPosition，诠释childPosition）{
返回true;
}
私有静态类ViewHolder {
TextView的称号;
}
私有静态类ChildViewHolder {
TextView的称号;
}
}
我希望这有助于！
更新
这是我如何调用上面的适配器的例子。
MainActivity：
@覆盖
保护无效的onCreate（包savedInstanceState）{
super.onCreate（savedInstanceState）;
最后的名单，其中，对象＆gt;对象= yourItems;
如果（！objects.isEmpty（））{
最后ExpandableListView ELV =（ExpandableListView）findViewById（R.id.yourExpandableListView）;
/ * *以下项目点击监听器/
在ExpandableListView //第一级项目
elv.setOnGroupClickListener（新ExpandableListView.OnGroupClickListener（）{
@覆盖
公共布尔onGroupClick（ExpandableListView eListView，视图中查看，INT groupPosition，
长ID）{
// TODO：你需要什么
返回false / *或真正取决于你所需要的* /;
}
}）;
在ExpandableListView //第二级项目
ExpandableListView.OnGroupClickListener grpLst =新ExpandableListView.OnGroupClickListener（）{
@覆盖
公共布尔onGroupClick（ExpandableListView eListView，视图中查看，INT groupPosition，
长ID）{
// TODO：你需要什么
返回false / *或真正取决于你所需要的* /;
}
};
//第三个（也是最后一次）的ExpandableListView级别的项目
ExpandableListView.OnChildClickListener childLst =新ExpandableListView.OnChildClickListener（）{
@覆盖
公共布尔onChildClick（ExpandableListView eListView，视图中查看，INT groupPosition，
INT childPosition，长ID）{
// TODO：你需要什么
返回false / *或真正取决于你所需要的* /;
}
};
ExpandableListView.OnGroupExpandListener grpExpLst =新ExpandableListView.OnGroupExpandListener（）{
@覆盖
公共无效onGroupExpand（INT groupPosition）{
/ *这个人是不是必需的，当然，你可以从RootAdapter构造函数删除
*这只是一个例子，如何实现第二个层次的项目听众* /
}
};
最后RootAdapter适配器=新RootAdapter（这一点，对象，grpLst，childLst，grpExpLst）;
elv.setAdapter（适配器）;
}
}
这是我的类对象将是什么样子。
Object.java：
公共类对象{
公共字符串称号; //使用getter和setter方法，而不是
公开名单＆LT;对象＆gt;儿童; //与上述相同的
公共对象（）{
孩子=新的ArrayList＆LT;对象＆gt;（）;
}
}
I have a multi level (3 levels, Root -> Parent -> Child) ExpandableListView containing children that are also ExpandableListViews. I'm having no issue filling them up; however, I need to expand a specific item in the Parent level when I first display the Activity (onCreate).
I successfully expand the related Root item of the Parent but I can't seem to expand the Parent item. The given listeners are called and yet the result isn't reflected in my multi level list.
Activity in which I call the expansion:
public class Activity {
private int groupToExpand = 4, childToExpand = 3;
protected void onCreate(Bundle savedInstance) {
final ExpandableListView elv = (ExpandableListView) findViewById(R.id.elv);
if (arrayList!= null && !arrayList.isEmpty()) {
elv.setAdapter(new RootAdapter(this, arrayList);
// this selects the correct group, but doesn't expand the child.
elv.setSelectedChild(groupToExpand, childToExpand, true);
elv.expandGroup(groupToExpand); // this works.
}
}
}
My Root adapter:
public class RootAdapter extends BaseExpandableListAdapter {
private List<Objects> arrayList;
private Context context;
private LayoutInflater inflater;
public RootAdapter(Context context, List<Objects> arrayList) {
this.context = context;
this.arrayList = arrayList;
this.inflater = LayoutInflater.from(context);
}
@Override
public Object getChild(int groupPosition, int childPosition) {
final Objects parent = (Objects) getGroup(groupPosition);
return parent.arrayList.get(childPosition);
}
@Override
public long getChildId(int groupPosition, int childPosition) {
return childPosition;
}
@Override
public View getChildView(int groupPosition, int childPosition,
boolean isLastChild, View convertView, ViewGroup parent) {
final Objects o = (Objects) getChild(groupPosition, childPosition);
CustomExpandableListView elv = (CustomExpandableListView) convertView;
ChildViewHolder holder;
if (elv == null) {
holder = new ChildViewHolder();
elv = new CustomExpandableListView(context);
elv.setGroupIndicator(null);
elv.setDivider(null);
elv.setCacheColorHint(Color.parseColor("#00000000"));
elv.setChildDivider(null);
elv.setChildIndicator(null);
elv.setScrollingCacheEnabled(false);
elv.setAnimationCacheEnabled(false);
holder.cListView = elv;
elv.setTag(holder);
} else {
holder = (ChildViewHolder) elv.getTag();
}
final ParentAdapter adapter = new ParentAdapter(context, o);
holder.cListView.setAdapter(adapter);
return elv;
}
private static class ChildViewHolder {
CustomExpandableListView cListView;
}
@Override
public int getChildrenCount(int groupPosition) {
final Objects parent = (Objects) getGroup(groupPosition);
return parent.arrayList.size();
}
@Override
public Object getGroup(int groupPosition) {
return arrayList.get(groupPosition);
}
@Override
public int getGroupCount() {
return arrayList.size();
}
@Override
public long getGroupId(int groupPosition) {
return groupPosition;
}
@Override
public View getGroupView(int groupPosition, boolean isExpanded,
View convertView, ViewGroup parent) {
View layout = convertView;
GroupViewHolder holder;
final Objects o = (Objects) getGroup(groupPosition);
if (layout == null) {
layout = inflater.inflate(R.layout.item_to_inflate, parent, false);
holder = new GroupViewHolder();
holder.title = (TextView) layout.findViewById(R.id.title);
holder.image = (ImageView) layout.findViewById(R.id.image);
layout.setTag(holder);
} else {
holder = (GroupViewHolder) layout.getTag();
}
holder.title.setText(o.title.trim());
return layout;
}
@Override
public boolean hasStableIds() {
return true;
}
@Override
public boolean isChildSelectable(int groupPosition, int childPosition) {
return true;
}
private static class GroupViewHolder {
TextView title;
ImageView image;
}
public class CustomExpandableListView extends ExpandableListView {
public CustomExpandableListView(Context context) {
super(context);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
heightMeasureSpec = MeasureSpec.makeMeasureSpec(2000, MeasureSpec.AT_MOST);
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
}
}
Finally my ParentAdapter :
public class ParentAdapter extends BaseExpandableListAdapter {
private Objects child;
private LayoutInflater inflater;
public ParentAdapter(Context context, Objects child) {
this.child = child;
this.inflater = LayoutInflater.from(context);
}
@Override
public Object getChild(int groupPosition, int childPosition) {
return child.arrayList.get(childPosition);
}
@Override
public long getChildId(int groupPosition, int childPosition) {
return childPosition;
}
@Override
public View getChildView(int groupPosition, int childPosition,
boolean isLastChild, View convertView, ViewGroup parent) {
View layout = convertView;
final Objects o = (Objects) getChild(0, childPosition);
ChildViewHolder holder;
if (layout == null) {
layout = inflater.inflate(R.layout.item_to_inflate, parent, false);
holder = new ChildViewHolder();
holder.title = (TextView) layout.findViewById(R.id.title);
layout.setTag(holder);
} else {
holder = (ChildViewHolder) layout.getTag();
}
holder.title.setText(o.title.trim());
return layout;
}
@Override
public int getChildrenCount(int groupPosition) {
return child.arrayList.size();
}
@Override
public Object getGroup(int groupPosition) {
return child;
}
@Override
public int getGroupCount() {
return 1;
}
@Override
public long getGroupId(int groupPosition) {
return groupPosition;
}
@Override
public View getGroupView(int groupPosition, boolean isExpanded,
View convertView, ViewGroup parent) {
View layout = convertView;
GroupViewHolder holder;
if (layout == null) {
layout = inflater.inflate(R.layout.item_to_inflate, parent, false);
holder = new GroupViewHolder();
holder.image = (ImageView) layout.findViewById(R.id.image);
holder.title = (TextView) layout.findViewById(R.id.title);
layout.setTag(holder);
} else {
holder = (GroupViewHolder) layout.getTag();
}
holder.title.setText(o.title.trim());
return layout;
}
@Override
public boolean hasStableIds() {
return true;
}
@Override
public boolean isChildSelectable(int groupPosition, int childPosition) {
return true;
}
private static class GroupViewHolder {
TextView title;
ImageView image;
}
private static class ChildViewHolder {
TextView title;
}
}
I can't expand the child lists within the root ExpandableListView; do you know any correct way to expand the items at the Parent level?
I tried in getChildView of the RootAdapter :
if (groupToExpand == groupPosition && childToExpand == childPosition) {
elv.expandGroup(childToExpand);
}
Then in the activity i changed:
if (arrayList!= null && !arrayList.isEmpty()) {
RootAdapter adapter = new RootAdapter(this, arrayList);
elv.setAdapter(adapter);
// this selects the correct group, but doesn't expand the child.
elv.setSelectedChild(groupToExpand, childToExpand, true);
elv.expandGroup(groupToExpand); // this works.
adapter.groupToExpand = groupToExpand;
adapter.childToExpand = childToExpand;
adapter.notifyDataSetChanged();
}
This expands the Parent level item, BUT, it generates duplicate items of the Parent. How do I do this correctly? Is this the correct way but my adapter is broken, therefore generating duplicate items?
I just can't find what I'm missing here...
解决方案
I ended up using a multi level ExpandableListView adapter from another post in stackoverflow. Unfortunately I just can't find the link anymore so I'll just post my code here.
Top Level of the ExpandableListView adapter.
RootAdapter.java:
public class RootAdapter extends BaseExpandableListAdapter {
private Object root;
private final LayoutInflater inflater;
public class Entry {
public final CustExpListview cls;
public final SecondLevelAdapter sadpt;
public Entry(CustExpListview cls, SecondLevelAdapter sadpt) {
this.cls = cls;
this.sadpt = sadpt;
}
}
public Entry[] lsfirst;
// you can change the constructor depending on which listeners you wan't to use.
public RootAdapter(Context context, Object root, ExpandableListView.OnGroupClickListener grpLst,
ExpandableListView.OnChildClickListener childLst, ExpandableListView.OnGroupExpandListener grpExpLst) {
this.root = root;
this.inflater = LayoutInflater.from(context);
lsfirst = new Entry[root.children.size()];
for (int i = 0; i < root.children.size(); i++) {
final CustExpListview celv = new CustExpListview(context);
SecondLevelAdapter adp = new SecondLevelAdapter(root.children.get(i));
celv.setAdapter(adp);
celv.setGroupIndicator(null);
celv.setOnChildClickListener(childLst);
celv.setOnGroupClickListener(grpLst);
celv.setOnGroupExpandListener(grpExpLst);
lsfirst[i] = new Entry(celv, adp);
}
}
@Override
public Object getChild(int groupPosition, int childPosition) {
return childPosition;
}
@Override
public long getChildId(int groupPosition, int childPosition) {
return childPosition;
}
@Override
public View getChildView(int groupPosition, int childPosition, boolean isLastChild,
View convertView, ViewGroup parent) {
// second level list
return lsfirst[groupPosition].cls;
}
@Override
public int getChildrenCount(int groupPosition) {
return 1;
}
@Override
public Object getGroup(int groupPosition) {
return root.children.get(groupPosition);
}
@Override
public int getGroupCount() {
return root.children.size();
}
@Override
public long getGroupId(int groupPosition) {
return groupPosition;
}
@Override
public View getGroupView(int groupPosition, boolean isExpanded, View convertView,
ViewGroup parent) {
// first level
View layout = convertView;
GroupViewHolder holder;
final Object item = (Object) getGroup(groupPosition);
if (layout == null) {
layout = inflater.inflate(R.layout.item_root, parent, false);
holder = new GroupViewHolder();
holder.title = (TextView) layout.findViewById(R.id.itemRootTitle);
layout.setTag(holder);
} else {
holder = (GroupViewHolder) layout.getTag();
}
holder.title.setText(item.title.trim());
return layout;
}
private static class GroupViewHolder {
TextView title;
}
@Override
public boolean hasStableIds() {
return true;
}
@Override
public boolean isChildSelectable(int groupPosition, int childPosition) {
return true;
}
}
Custom ExpandableListView with the solution to items sometimes not being displayed. There is also a workaround to a known bug for IllegalArgumentException being called when destroying the view (by pressing the back button essentially).
CustExpListview.java:
public class CustExpListview extends ExpandableListView {
public CustExpListview(Context context) {
super(context);
}
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
// the value (2000) should not be fixed and be calculated
// as follows: cell_height x root_items_count x root_items_children_count
heightMeasureSpec = MeasureSpec.makeMeasureSpec(2000, MeasureSpec.AT_MOST);
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
@Override
protected void onDetachedFromWindow() {
try {
super.onDetachedFromWindow();
} catch (IllegalArgumentException e) {
// TODO: Workaround for http://code.google.com/p/android/issues/detail?id=22751
}
}
}
Finally, the code to the last level adapter.
public class SecondLevelAdapter extends BaseExpandableListAdapter {
public Object child;
public SecondLevelAdapter(Object child) {
this.child = child;
}
@Override
public Object getChild(int groupPosition, int childPosition) {
return child.children.get(groupPosition).children.get(childPosition);
}
@Override
public long getChildId(int groupPosition, int childPosition) {
return childPosition;
}
// third level
@Override
public View getChildView(int groupPosition, int childPosition, boolean isLastChild,
View convertView, ViewGroup parent) {
View layout = convertView;
final Object item = (Object) getChild(groupPosition, childPosition);
ChildViewHolder holder;
if (layout == null) {
layout = inflater.inflate(R.layout.item_child, parent, false);
holder = new ChildViewHolder();
holder.title = (TextView) layout.findViewById(R.id.itemChildTitle);
layout.setTag(holder);
} else {
holder = (ChildViewHolder) layout.getTag();
}
holder.title.setText(item.title.trim());
return layout;
}
@Override
public int getChildrenCount(int groupPosition) {
return child.children.get(groupPosition).children.size();
}
@Override
public Object getGroup(int groupPosition) {
return child.children.get(groupPosition);
}
@Override
public int getGroupCount() {
return child.children.size();
}
@Override
public long getGroupId(int groupPosition) {
return groupPosition;
}
// Second level
@Override
public View getGroupView(int groupPosition, boolean isExpanded, View convertView,
ViewGroup parent) {
View layout = convertView;
ViewHolder holder;
final Object item = (Object) getGroup(groupPosition);
if (layout == null) {
layout = inflater.inflate(R.layout.item_parent, parent, false);
holder = new ViewHolder();
holder.title = (TextView) layout.findViewById(R.id.itemParentTitle);
layout.setTag(holder);
} else {
holder = (ViewHolder) layout.getTag();
}
holder.title.setText(item.title.trim());
return layout;
}
@Override
public void registerDataSetObserver(DataSetObserver observer) {
super.registerDataSetObserver(observer);
}
@Override
public void unregisterDataSetObserver(DataSetObserver observer) {
Log.d("SecondLevelAdapter", "Unregistering observer");
if (observer != null) {
super.unregisterDataSetObserver(observer);
}
}
@Override
public boolean hasStableIds() {
return true;
}
@Override
public boolean isChildSelectable(int groupPosition, int childPosition) {
return true;
}
private static class ViewHolder {
TextView title;
}
private static class ChildViewHolder {
TextView title;
}
}
I hope this helps!!!
Update
This is an example of how I call the above adapter.
MainActivity:
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
final List<Object> objects = yourItems;
if (!objects.isEmpty()) {
final ExpandableListView elv = (ExpandableListView) findViewById(R.id.yourExpandableListView);
/* Item click listeners below */
// First level items in the ExpandableListView
elv.setOnGroupClickListener(new ExpandableListView.OnGroupClickListener() {
@Override
public boolean onGroupClick(ExpandableListView eListView, View view, int groupPosition,
long id) {
// TODO: whatever you need
return false /* or true depending on what you need */;
}
});
// Second level items in the ExpandableListView
ExpandableListView.OnGroupClickListener grpLst = new ExpandableListView.OnGroupClickListener() {
@Override
public boolean onGroupClick(ExpandableListView eListView, View view, int groupPosition,
long id) {
// TODO: whatever you need
return false /* or true depending on what you need */;
}
};
// Third (and last) level items in the ExpandableListView
ExpandableListView.OnChildClickListener childLst = new ExpandableListView.OnChildClickListener() {
@Override
public boolean onChildClick(ExpandableListView eListView, View view, int groupPosition,
int childPosition, long id) {
// TODO: whatever you need
return false /* or true depending on what you need */;
}
};
ExpandableListView.OnGroupExpandListener grpExpLst = new ExpandableListView.OnGroupExpandListener() {
@Override
public void onGroupExpand(int groupPosition) {
/* this one is not required of course, you can delete it from the RootAdapter Constructor
* it is just an example as to how to implement Listeners on the second level items */
}
};
final RootAdapter adapter = new RootAdapter(this, objects, grpLst, childLst, grpExpLst);
elv.setAdapter(adapter);
}
}
This is how my class Object would look like.
Object.java:
public class Object {
public String title; // use getters and setters instead
public List<Object> children; // same as above
public Object() {
children = new ArrayList<Object>();
}
}
这篇关于问题展开多层次ExpandableListView的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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