我正在尝试使用可扩展listview的自定义实现创建一个无限可扩展的列表视图。 我的代码基于How to display more than 3- levels of expandable List View?。
不幸的是，我的listview只显示三个级别，即使树中包含更多嵌套项目，也无法扩展到该级别。
这是我的代码：
public class RootAdapter extends BaseExpandableListAdapter {
private UserObject root;
private final LayoutInflater listLayoutInflater;
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, UserObject root, ExpandableListView.OnGroupClickListener grpLst,
final ExpandableListView.OnChildClickListener childLst, ExpandableListView.OnGroupExpandListener grpExpLst) {
this.root = root;
this.listLayoutInflater = LayoutInflater.from(context);
lsfirst = new Entry[root.mChildren.size()];
for (int i = 0; i < root.mChildren.size(); i++) {
final CustExpListview celv = new CustExpListview(context);
SecondLevelAdapter adp = new SecondLevelAdapter(root.mChildren.get(i),context);
celv.setLongClickable(true);
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 root.mChildren.get(groupPosition);
}
@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 UserObject getGroup(int groupPosition) {
return root.mChildren.get(groupPosition);
}
@Override
public int getGroupCount() {
return root.mChildren.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 UserObject item = (UserObject) getGroup(groupPosition);
if (layout == null) {
layout = listLayoutInflater.inflate(R.layout.root_element, parent, false);
holder = new GroupViewHolder();
holder.title = (TextView) layout.findViewById(R.id.rootTitle);
layout.setTag(holder);
} else {
holder = (GroupViewHolder) layout.getTag();
}
holder.title.setText(item.mUserName.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;
}
}
接下来是我的第二级适配器实现（即：叶节点）
public class SecondLevelAdapter extends BaseExpandableListAdapter {
public UserObject child;
Context mContext;
LayoutInflater inflater;
public SecondLevelAdapter(UserObject child,Context context) {
this.child = child;
this.mContext=context;
inflater = LayoutInflater.from(mContext);
}
@Override
public UserObject getChild(int groupPosition, int childPosition) {
return child.mChildren.get(groupPosition).mChildren.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 UserObject item = (UserObject) 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.childTitle);
layout.setTag(holder);
} else {
holder = (ChildViewHolder) layout.getTag();
}
holder.title.setText(item.mUserName.trim());
return layout;
}
@Override
public int getChildrenCount(int groupPosition) {
return child.mChildren.get(groupPosition).mChildren.size();
}
@Override
public UserObject getGroup(int groupPosition) {
return child.mChildren.get(groupPosition);
}
@Override
public int getGroupCount() {
return child.mChildren.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 UserObject item = (UserObject) getGroup(groupPosition);
if (layout == null) {
layout = inflater.inflate(R.layout.root_element, parent, false);
holder = new ViewHolder();
holder.title = (TextView) layout.findViewById(R.id.rootTitle);
layout.setTag(holder);
} else {
holder = (ViewHolder) layout.getTag();
}
holder.title.setText(item.mUserName.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;
}
}
然后我在主要活动中调用此代码：
public class Test extends navBar {
private List<UserObject> mUserObjects;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
View base = getLayoutInflater().inflate(R.layout.activity_admin__tool, frameLayout);
mUserObjects = new ArrayList<>();
UserObject obj = new UserObject();
obj.mChildren = new ArrayList<>();
for(int i = 0;i<Constant.state.length;i++) {
root = new UserObject();
root.mUserName = Constant.state[i];
root.mChildren = new ArrayList<>();
for (int j = 0; j < Constant.parent[i].length; j++) {
UserObject parent = new UserObject();
parent.mUserName = Constant.parent[i][j];
parent.mChildren = new ArrayList<>();
for (int k = 0; k < Constant.child[i][j].length; k++) {
UserObject child = new UserObject();
child.mUserName = Constant.child[i][j][k];
UserObject test = new UserObject();
test.mUserName = "test";
child.mChildren.add(test);
parent.mChildren.add(child);
}
root.mChildren.add(parent);
}
obj.mChildren.add(root);
}
if (!obj.mChildren.isEmpty()) {
final ExpandableListView elv = (ExpandableListView) base.findViewById(R.id.expandableListView);
/* Item click listeners below */
try {
// First level items in the ExpandableListView
elv.setLongClickable(true);
elv.setOnGroupClickListener(new ExpandableListView.OnGroupClickListener() {
@Override
public boolean onGroupClick(ExpandableListView eListView, View view, int groupPosition,
long id) {
ImageView tv = (ImageView) view.findViewById(R.id.rootImage);
if(!eListView.isGroupExpanded(groupPosition)){
tv.setImageResource(R.drawable.ic_expand_less_black_24dp);
}
else
tv.setImageResource(R.drawable.ic_expand_more_black_24dp);
return false /* or true depending on what you need */;
}
});
elv.setOnItemLongClickListener(new ExpandableListView.OnItemLongClickListener() {
@Override
public boolean onItemLongClick(AdapterView<?> parent, View childView, int flatPos, long id) {
if (ExpandableListView.getPackedPositionType(id) == ExpandableListView.PACKED_POSITION_TYPE_CHILD) {
// do whatever you want with groupPos and childPos here - I used these to get my object from list adapter.
return false;
}
return true;
}
});
}
catch (Exception e){
Log.e("Admin_Tool",e.getMessage());
}
// Second level items in the ExpandableListView
ExpandableListView.OnGroupClickListener grpLst = new ExpandableListView.OnGroupClickListener() {
@Override
public boolean onGroupClick(ExpandableListView eListView, View view, int groupPosition,
long id) {
ImageView tv = (ImageView) view.findViewById(R.id.rootImage);
if(!eListView.isGroupExpanded(groupPosition)){
tv.setImageResource(R.drawable.ic_expand_less_black_24dp);
}
else
tv.setImageResource(R.drawable.ic_expand_more_black_24dp);
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, obj, grpLst, childLst, grpExpLst);
elv.setAdapter(adapter);
}
}
最后，常量设置如下：
public class Constant {
static String[] state = {"A","B","C"};
static String[][] parent = {
{"aa","bb","cc","dd","ee"},
{"ff","gg","hh","ii","jj"},
{"kk","ll","mm","nn","oo"}
};
static String[][][] child = {
{
{"aaa","aab","aac","aad","aae"},
{"bba","bbb","bbc","bbd","bbe"},
{"cca","ccb","ccc","ccd","cce","ccf","ccg"},
{"dda","ddb","dddc","ddd","dde","ddf"},
{"eea","eeb","eec"}
},
{
{"ffa","ffb","ffc","ffd","ffe"},
{"gga","ggb","ggc","ggd","gge"},
{"hha","hhb","hhc","hhd","hhe","hhf","hhg"},
{"iia","iib","iic","iid","iie","ii"},
{"jja","jjb","jjc","jjd"}
},
{
{"kka","kkb","kkc","kkd","kke"},
{"lla","llb","llc","lld","lle"},
{"mma","mmb","mmc","mmd","mme","mmf","mmg"},
{"nna","nnb","nnc","nnd","nne","nnf"},
{"ooa","oob"}
}
};
}
我将“test”添加为所有第三级节点的节点，以确保它将测试第四级节点。因此，一个例子是a-＆gt; aa＆gt; aaa＆gt;测试 测试永远不会显示，并且aaa始终被视为最终节点。 我如何超越三个级别？
答案 0 :(得分：2)
结帐此库：AndroidTreeView
为项目添加依赖项
compile 'com.github.bmelnychuk:atv:1.2.+'
创建树
TreeNode root = TreeNode.root();
添加节点（使用自定义对象作为构造函数参数）
TreeNode parent = new TreeNode("MyParentNode");
TreeNode child0 = new TreeNode("ChildNode0");
TreeNode child1 = new TreeNode("ChildNode1");
parent.addChildren(child0, child1);
root.addChild(parent);
将树视图添加到布局
AndroidTreeView tView = new AndroidTreeView(getActivity(), root);
containerView.addView(tView.getView());
答案 1 :(得分：0)
您好here is a full tutorial for listview and cache items
我希望这篇文章可以帮到你。祝你好运