我正在尋求編寫自己的ExpandableListAdapter，其操作方式與ArrayAdapter相似。我的數據模型是這樣的：如何編寫自定義ExpandableListAdapter
public class Group {
private String name;
private List<Child> children;
}
public class Child {
private String name;
}
很簡單。我如何將這種關係映射爲ExpandableListAdapter實現？我現在有一個工作SimpleExpandableListAdapter工作，但我需要更多的自定義項目控制（顯示圖標等）。我應該怎麼做？
最主要的是我需要一個add()方法來添加組，並且當從適配器中添加和刪除子組時，使列表無效。我真的很驚訝，SDK中沒有實現（甚至是抽象的），這有助於實現這一點。
這是我剛剛提出的一個實現。我不知道它是否有效，但對我來說似乎是「聰明」:)順便說一下，應該如何獲得組合的兒童ID或組合的組ID，所以我只是在那裏即興創作。
package example;
import java.util.ArrayList;
import java.util.List;
import java.util.Map.Entry;
import android.content.Context;
import android.database.DataSetObservable;
import android.database.DataSetObserver;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ExpandableListAdapter;
public abstract class AbstractExpandableListAdapter<A, B> implements ExpandableListAdapter {
private final List<Entry<A, List<B>>> objects;
private final DataSetObservable dataSetObservable = new DataSetObservable();
private final Context context;
private final Integer groupClosedView;
private final Integer groupExpandedView;
private final Integer childView;
private final LayoutInflater inflater;
public AbstractExpandableListAdapter(Context context, int groupClosedView,
int groupExpandedView, int childView, List<Entry<A, List<B>>> objects) {
this.context = context;
this.objects = objects;
this.groupClosedView = new Integer(groupClosedView);
this.groupExpandedView = new Integer(groupExpandedView);
this.childView = new Integer(childView);
this.inflater = (LayoutInflater) this.context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
public void add(Entry<A, List<B>> group) {
this.getObjects().add(group);
this.notifyDataSetChanged();
}
public void remove(A group) {
for (Entry<A, List<B>> entry : this.getObjects()) {
if (entry != null && entry.getKey().equals(group)) {
this.getObjects().remove(group);
this.notifyDataSetChanged();
break;
}
}
}
public void remove(Entry<A, List<B>> entry) {
remove(entry.getKey());
}
public void addChild(A group, B child) {
for (Entry<A, List<B>> entry : this.getObjects()) {
if (entry != null && entry.getKey().equals(group)) {
if (entry.getValue() == null)
entry.setValue(new ArrayList<B>());
entry.getValue().add(child);
this.notifyDataSetChanged();
break;
}
}
}
public void removeChild(A group, B child) {
for (Entry<A, List<B>> entry : this.getObjects()) {
if (entry != null && entry.getKey().equals(group)) {
if (entry.getValue() == null)
return;
entry.getValue().remove(child);
this.notifyDataSetChanged();
break;
}
}
}
public void notifyDataSetChanged() {
this.getDataSetObservable().notifyChanged();
}
public void notifyDataSetInvalidated() {
this.getDataSetObservable().notifyInvalidated();
}
public void registerDataSetObserver(DataSetObserver observer) {
this.getDataSetObservable().registerObserver(observer);
}
public void unregisterDataSetObserver(DataSetObserver observer) {
this.getDataSetObservable().unregisterObserver(observer);
}
public int getGroupCount() {
return getObjects().size();
}
public int getChildrenCount(int groupPosition) {
return getObjects().get(groupPosition).getValue().size();
}
public Object getGroup(int groupPosition) {
return getObjects().get(groupPosition).getKey();
}
public Object getChild(int groupPosition, int childPosition) {
return getObjects().get(groupPosition).getValue().get(childPosition);
}
public long getGroupId(int groupPosition) {
return ((Integer)groupPosition).longValue();
}
public long getChildId(int groupPosition, int childPosition) {
return ((Integer)childPosition).longValue();
}
public boolean hasStableIds() {
return true;
}
public View getGroupView(int groupPosition, boolean isExpanded,
View convertView, ViewGroup parent) {
if (convertView != null && convertView.getId() !=
(isExpanded ? getGroupExpandedView() : getGroupClosedView())) {
// do nothing, we're good to go, nothing has changed.
} else {
// something has changed, update.
convertView = inflater.inflate(isExpanded ? getGroupExpandedView() :
getGroupClosedView(), parent, false);
convertView.setTag(getObjects().get(groupPosition));
}
return convertView;
}
public View getChildView(int groupPosition, int childPosition,
boolean isLastChild, View convertView, ViewGroup parent) {
if (convertView != null) {
// do nothing
} else {
// create
convertView = inflater.inflate(getChildView(), parent, false);
convertView.setTag(getObjects().get(groupPosition).getValue().get(childPosition));
}
return convertView;
}
public boolean isChildSelectable(int groupPosition, int childPosition) {
return true;
}
public boolean areAllItemsEnabled() {
return true;
}
public boolean isEmpty() {
return getObjects().size() == 0;
}
public void onGroupExpanded(int groupPosition) {
}
public void onGroupCollapsed(int groupPosition) {
}
public long getCombinedChildId(long groupId, long childId) {
return groupId * 10000L + childId;
}
public long getCombinedGroupId(long groupId) {
return groupId * 10000L;
}
protected DataSetObservable getDataSetObservable() {
return dataSetObservable;
}
protected List<Entry<A, List<B>>> getObjects() {
return objects;
}
protected Context getContext() {
return context;
}
protected Integer getGroupClosedView() {
return groupClosedView;
}
protected Integer getGroupExpandedView() {
return groupExpandedView;
}
protected Integer getChildView() {
return childView;
}
}
歡迎任何評論或批評。
我很驚訝我沒有找到更好的文檔。如果你找到一個，請在這裏發佈。我發現的最好的實現例子是ApiDemos。有一個ExpandableListActivity，實現了BaseExpandableListAdapter。該類被稱爲ExpandableList1.java。
您將不得不創建自己的add()方法，將Group和Child類添加到適配器。我認爲乍看起來不會那麼困難。實際上你可能只能創建對類對象的引用。當我實現我的時候，我的數據集很小，並沒有改變，所以我只需要引用我的array.xml文件。
public class CustomExpandableAdapter extends BaseExpandableListAdapter {
private Context mContext;
private List<Group> mData;
private int mSelectedPosition = -1;
public CustomExpandableAdapter(Context context, List<Group> data) {
mData = data;
mContext = context;
}
@Override
public int getGroupCount() {
return mData.size();
}
@Override
public int getChildrenCount(int groupPosition) {
return mData.get(groupPosition).children.size();
}
@Override
public Object getGroup(int groupPosition) {
return mData.get(groupPosition);
}
@Override
public Object getChild(int groupPosition, int childPosition) {
return mData.get(groupPosition).children.get(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) {
HeaderViewHolder headerViewHolder = null;
if (convertView == null) {
convertView = LayoutInflater.from(mContext).inflate(R.layout.faq_header_text_layout, null);
headerViewHolder = new HeaderViewHolder(convertView);
convertView.setTag(headerViewHolder);
}
headerViewHolder = (HeaderViewHolder) convertView.getTag();
headerViewHolder.mGroupHeader.setText(mData.get(groupPosition).name);
return convertView;
}
@Override
public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView, ViewGroup parent) {
ChildViewHolder childViewHolder = null;
if (convertView == null) {
convertView = LayoutInflater.from(mContext).inflate(R.layout.faq_textview_layout, null);
childViewHolder = new ChildViewHolder(convertView);
convertView.setTag(childViewHolder);
}
childViewHolder = (ChildViewHolder) convertView.getTag();
childViewHolder.mChildTitle.setText(mData.get(groupPosition).children.get(childPosition));
return convertView;
}
@Override
public boolean isChildSelectable(int groupPosition, int childPosition) {
return false;
}
private static class HeaderViewHolder {
final TextView mGroupHeader;
private HeaderViewHolder(View group) {
mGroupHeader = (TextView) group.findViewById(R.id.txv_faq_header_text_layout);
}
}
private static class ChildViewHolder {
final TextView mChildTitle;
private ChildViewHolder(View group) {
mChildTitle = (TextView) group.findViewById(R.id.txv_faq_textview_layout);
}
}
@Override
public void unregisterDataSetObserver(DataSetObserver observer) {
if (observer != null) {
super.unregisterDataSetObserver(observer);
}
}
public void setSelectedPosition(int selectedPosition) {
mSelectedPosition = selectedPosition;
}
}
看到這篇文章，答案多大年紀了，我以爲我會指出，有一個非常好的3rd party library是八九不離十填補這個缺失的空白。雖然發佈的定製解決方案很好，但仍然缺少一些東西，並且遵循繁瑣的設計，要求程序員生成數據結構的數據結構。有時候，你只想把一個List組織成好的小組，而沒有你自己做的麻煩。
這就是所謂的RolodexArrayAdapter，可以創建自定義ExpandableListAdapters很容易地利用......而不必擔心所有的數據管理問題和特點。它支持add，addAll，remove，removeAll，retainAll，contains，sorting等方法。它還支持更多高級功能，如ChoiceMode，Filtering和自動擴展組。
例子：
class MovieAdapter extends RolodexArrayAdapter<Integer, MovieItem> {
public MovieAdapter(Context activity, List<MovieItem> movies) {
super(activity, movies);
}
@Override
public Integer createGroupFor(MovieItem childItem) {
//Lets organize our movies by their release year
return childItem.year;
}
@Override
public View getChildView(LayoutInflater inflater, int groupPosition, int childPosition,
boolean isLastChild, View convertView, ViewGroup parent) {
if (convertView == null) {
//Inflate your view
}
//Fill view with data
return convertView;
}
@Override
public View getGroupView(LayoutInflater inflater, int groupPosition, boolean isExpanded,
View convertView, ViewGroup parent) {
if (convertView == null) {
//Inflate your view
}
//Fill view with data
return convertView;
}
@Override
public boolean hasAutoExpandingGroups() {
return true;
}
@Override
protected boolean isChildFilteredOut(MovieItem movie, CharSequence constraint) {
//Lets filter by movie title
return !movie.title.toLowerCase(Locale.US).contains(
constraint.toString().toLowerCase(Locale.US));
}
@Override
protected boolean isGroupFilteredOut(Integer year, CharSequence constraint) {
//Lets filter out everything whose year does not match the numeric values in the constraint.
return TextUtils.isDigitsOnly(constraint) && !year.toString().contains(constraint);
}
}
順便說一句，只是測試這一點，它似乎工作的偉大。 :) – 2011-03-04 22:28:00
剛剛出色，謝謝！ – myforums 2014-11-17 19:18:56
讓人印象深刻的是當場鞭打。 – 2015-02-08 22:02:07