Java 在android的可展开列表视图中单击父列表项时加载子项
我正在开发一个Android应用程序,其中包含一个可扩展的列表视图,用于从web服务加载数据,但我不想在启动时加载整个数据,而是首先加载父列表,然后在扩展列表视图的特定列表项时加载该特定项的子项,那么首先是否可能 我的示例代码:Java 在android的可展开列表视图中单击父列表项时加载子项,java,android,expandablelistview,Java,Android,Expandablelistview,我正在开发一个Android应用程序,其中包含一个可扩展的列表视图,用于从web服务加载数据,但我不想在启动时加载整个数据,而是首先加载父列表,然后在扩展列表视图的特定列表项时加载该特定项的子项,那么首先是否可能 我的示例代码: package adapter; import android.content.Context; import android.view.LayoutInflater; import android.view.View; import android.view.Vie
package adapter;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseExpandableListAdapter;
import android.widget.TextView;
import com.rk.socialsync.R;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import utils.Global;
import utils.OnlineProperty;
public class ExpandableListAdapter extends BaseExpandableListAdapter {
private Context _context;
private List<Date> _listDataHeader;
private HashMap<Date, List<OnlineProperty>> _listDataChild;
public ExpandableListAdapter(Context context, List<Date> listDataHeader,
HashMap<Date, List<OnlineProperty>> listChildData) {
this._context = context;
this._listDataHeader = listDataHeader;
this._listDataChild = listChildData;
}
@Override
public OnlineProperty getChild(int groupPosition, int childPosititon) {
return this._listDataChild.get(this._listDataHeader.get(groupPosition))
.get(childPosititon);
}
@Override
public long getChildId(int groupPosition, int childPosition) {
return childPosition;
}
@Override
public View getChildView(int groupPosition, final int childPosition,
boolean isLastChild, View convertView, ViewGroup parent) {
OnlineProperty onlineProperty = getChild(groupPosition, childPosition);
String child1Text = onlineProperty.getOnlineTime();
String child2Text = onlineProperty.getOfflineTime();
if (convertView == null) {
LayoutInflater infalInflater = (LayoutInflater) this._context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = infalInflater.inflate(R.layout.listelementchild, null);
}
TextView textOnline = (TextView) convertView.findViewById(R.id.textTimeOnline);
TextView textOffline = (TextView) convertView.findViewById(R.id.textTimeOffline);
TextView textView = (TextView) convertView.findViewById(R.id.textTo);
textView.setTypeface(Global.AppsFont);
textOnline.setText(child1Text);
textOffline.setText(child2Text);
textOffline.setTypeface(Global.AppsFont);
textOnline.setTypeface(Global.AppsFont);
return convertView;
}
@Override
public int getChildrenCount(int groupPosition) {
return this._listDataChild.get(this._listDataHeader.get(groupPosition))
.size();
}
@Override
public String getGroup(int groupPosition) {
SimpleDateFormat dateFormat = new SimpleDateFormat("dd/MM/yyyy");
return dateFormat.format(this._listDataHeader.get(groupPosition));
}
@Override
public int getGroupCount() {
return this._listDataHeader.size();
}
@Override
public long getGroupId(int groupPosition) {
return groupPosition;
}
@Override
public View getGroupView(int groupPosition, boolean isExpanded,
View convertView, ViewGroup parent) {
String headerTitle = (String) getGroup(groupPosition);
if (convertView == null) {
LayoutInflater infalInflater = (LayoutInflater) this._context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = infalInflater.inflate(R.layout.listelementexpandable, null);
}
TextView textHeader = (TextView) convertView.findViewById(R.id.textExpandable);
textHeader.setTypeface(Global.AppsFont);
textHeader.setText(headerTitle);
return convertView;
}
@Override
public boolean hasStableIds() {
return false;
}
@Override
public boolean isChildSelectable(int groupPosition, int childPosition) {
return true;
}
}
包适配器;
导入android.content.Context;
导入android.view.LayoutInflater;
导入android.view.view;
导入android.view.ViewGroup;
导入android.widget.BaseExpandableListAdapter;
导入android.widget.TextView;
导入com.rk.socialsync.R;
导入java.text.simpleDataFormat;
导入java.util.Date;
导入java.util.HashMap;
导入java.util.List;
进口utils.Global;
导入utils.OnlineProperty;
公共类ExpandableListAdapter扩展了BaseExpandableListAdapter{
私人语境(private Context)(私人语境);;
私有列表listDataHeader;
私有HashMap_listDataChild;
公共ExpandableListAdapter(上下文、列表listDataHeader、,
HashMap listChildData){
这._context=context;
这。_listDataHeader=listDataHeader;
这。_listDataChild=listChildData;
}
@凌驾
公共OnlineProperty getChild(int-groupPosition、int-ChildPosition){
返回此。_listDataChild.get(此。_listDataHeader.get(groupPosition))
.get(childpositionon);
}
@凌驾
公共长getChildId(int-groupPosition,int-childPosition){
返回子位置;
}
@凌驾
公共视图getChildView(int groupPosition,final int childPosition,
布尔值isLastChild、视图转换视图、视图组父级){
OnlineProperty OnlineProperty=getChild(groupPosition,childPosition);
String child1Text=onlineProperty.getOnlineTime();
字符串child2Text=onlineProperty.getOfflineTime();
if(convertView==null){
LayoutInflater infalInflater=(LayoutInflater)this.\u上下文
.getSystemService(上下文布局\充气机\服务);
convertView=infalInflater.flate(R.layout.listlementchild,null);
}
TextView textOnline=(TextView)convertView.findViewById(R.id.textTimeOnline);
TextView textOffline=(TextView)convertView.findViewById(R.id.textTimeOffline);
TextView TextView=(TextView)convertView.findViewById(R.id.textTo);
setTypeface(Global.AppsFont);
textOnline.setText(child1Text);
textOffline.setText(child2Text);
textOffline.setTypeface(Global.AppsFont);
textOnline.setTypeface(Global.AppsFont);
返回视图;
}
@凌驾
公共整数getChildrenCount(整数组位置){
返回此。_listDataChild.get(此。_listDataHeader.get(groupPosition))
.size();
}
@凌驾
公共字符串getGroup(int-groupPosition){
SimpleDataFormat dateFormat=新的SimpleDataFormat(“dd/MM/yyyy”);
return dateFormat.format(this.\u listDataHeader.get(groupPosition));
}
@凌驾
public int getGroupCount(){
返回此值。_listDataHeader.size();
}
@凌驾
公共长getGroupId(int-groupPosition){
返回组位置;
}
@凌驾
公共视图getGroupView(int-groupPosition,布尔值isExpanded,
视图(视图、视图组父级){
字符串头文件=(字符串)getGroup(groupPosition);
if(convertView==null){
LayoutInflater infalInflater=(LayoutInflater)this.\u上下文
.getSystemService(上下文布局\充气机\服务);
convertView=infalInflater.充气(R.layout.listlementexpandable,null);
}
TextView textHeader=(TextView)convertView.findViewById(R.id.textExpandable);
textHeader.setTypeface(Global.AppsFont);
textHeader.setText(headerTitle);
返回视图;
}
@凌驾
公共布尔表ID(){
返回false;
}
@凌驾
公共布尔值isChildSelectable(int-groupPosition,int-childPosition){
返回true;
}
}
另一个问题是,我希望在布局中进行自定义更改,比如在图像中有点像“+”和“展开”按钮-
是的,这是可能的,应该通过您的
可扩展列表视图的OnGroupClickListener
来完成。首先,将适配器中的子数组设置为公共,并在默认情况下初始化:
public HashMap<Date, List<OnlineProperty>> _listDataChild =
new HashMap<Date, List<OnlineProperty>>();
注:
- 为了避免加载过多,您可以覆盖适配器中的
onGroupCollapsed
,使其卸载未使用的子级
- 我提供的代码可能不正确,因为我不知道您的数据结构。你必须适应
请一次问一个问题。是否可以从服务器加载子数据。非常适合本地数据
mExpList.setOnGroupClickListener(new ExpandableListView.OnGroupClickListener() {
@Override
public boolean onGroupClick(ExpandableListView p, View v, int grpPos, long id) {
// Check if children not yet fetched
if (mExpAdapter._listDataChild.get(date) == null) {
// Fetch list of children for group "grpPos"
// Add the children to your adapters HashMap
mExpAdapter._listDataChild.put(date, children);
}
return false;
}
});