Java 可扩展列表视图未显示child

我的应用程序中有一个可扩展的listview，可以从sqlite数据库中插入组childs。 在我的应用程序中，组标题不会更改

组显示在列表中，但未显示childs

这是我的适配器：

   package ir.TeenStudio.ActivitiesManagement;


import java.util.ArrayList;
import java.util.HashMap;

import android.app.Activity;
import android.content.Context;
import android.graphics.Typeface;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseExpandableListAdapter;
import android.widget.LinearLayout;
import android.widget.TextView;

public class ActivitiesExpandableListAdapter extends BaseExpandableListAdapter {

    Activity activity;
    ArrayList<String> groupsList;
    HashMap<Integer, ArrayList<HashMap<String,String>>> childsList;
    private ArrayList<HashMap<String,String>> items;
    private HashMap<String, String> item;
    private String groupItem;

    ActivitiesExpandableListAdapter(Activity activity, ArrayList<String> groupsList, HashMap<Integer, ArrayList<HashMap<String,String>>> childsList) {
        this.activity = activity;
        this.groupsList = groupsList;
        this.childsList = childsList;
    }

    @Override
    public Object getChild(int groupPosition, int childPosititon) {
        return this.childsList.get(this.groupsList.get(groupPosition)).get(childPosititon);
    }

    @Override
    public long getChildId(int groupPosition, int childPosititon) {
        return childPosititon;
    }

    @Override
    public View getChildView(int groupPosition, int childPosititon, boolean isLastChild, View convertView,
            ViewGroup parent) {

        View v = convertView;
        Holder viewHolder;
        if (v==null) {
            v = this.activity.getLayoutInflater().inflate(R.layout.list_item, null);
            viewHolder = new Holder();
            Typeface Rezvan = Typeface.createFromAsset(activity.getAssets(), "fonts/rezvan.ttf");
            viewHolder.ChildDescription = (TextView) v.findViewById(R.id.itemDescription);
            viewHolder.ChildLocation = (TextView) v.findViewById(R.id.itemLocation);
            viewHolder.ChildTime = (TextView) v.findViewById(R.id.itemTime);
            viewHolder.ChildDate = (TextView) v.findViewById(R.id.itemDate);
            viewHolder.ChildAlarmTime = (TextView) v.findViewById(R.id.alarmTime);
            viewHolder.ChildAlarmText = (TextView) v.findViewById(R.id.alarmText);
            viewHolder.ChildTime.setTypeface(Rezvan);
            viewHolder.ChildAlarmTime.setTypeface(Rezvan);
            viewHolder.ChildDate.setTypeface(Rezvan);

            v.setTag(viewHolder);
        }
        else 
            viewHolder = (Holder)v.getTag();

        this.items = this.childsList.get(groupPosition);
        this.item = this.items.get(childPosititon);

        viewHolder.ChildDescription.setText(this.item.get("Description"));
        if (Integer.parseInt(this.item.get("AddLocation"))==1) {
            viewHolder.ChildLocation.setText(this.item.get("Location"));
        } else ((LinearLayout)v.findViewById(R.id.location)).setVisibility(View.GONE);
        if (Integer.parseInt(this.item.get("AddHour"))==1) {
            viewHolder.ChildTime.setText(this.item.get("Hour")+":"+this.item.get("Minutes"));
        } else viewHolder.ChildTime.setVisibility(View.GONE);
        if (Integer.parseInt(this.item.get("AddDate"))==1) {
            viewHolder.ChildDate.setText(this.item.get("DateYear")+"/"+this.item.get("DateMonth")+"/"+this.item.get("DateDay"));
        } else ((LinearLayout)v.findViewById(R.id.date)).setVisibility(View.GONE);
        if (Integer.parseInt(this.item.get("AddAlarm"))==1) {
            if (Integer.parseInt(this.item.get("AlarmTime"))==0) {
                viewHolder.ChildAlarmTime.setText("");
                viewHolder.ChildAlarmText.setText("در زمان مشخص شده");
            } else {
                viewHolder.ChildAlarmTime.setText(this.item.get("AlarmTime"));
                viewHolder.ChildAlarmText.setText("دقیقه بعد از زمان مشخص شده");
            }
        } else ((LinearLayout)v.findViewById(R.id.alarm)).setVisibility(View.GONE);

        notifyDataSetChanged();


        return v;
    }

    @Override
    public int getChildrenCount(int groupPosition) {
        return 0;
    }

    @Override
    public Object getGroup(int groupPosition) {
        return this.groupsList.get(groupPosition);
    }

    @Override
    public int getGroupCount() {
        return this.groupsList.size();
    }

    @Override
    public long getGroupId(int groupPosition) {
        return groupPosition;
    }

    @Override
    public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {
        View v = convertView;
        Holder viewHolder;
        if (v == null) {
            v = this.activity.getLayoutInflater().inflate(R.layout.listview_group, null);
            viewHolder = new Holder();
            viewHolder.GroupTitle = (TextView) v.findViewById(R.id.itemDes);
            Typeface Naskh = Typeface.createFromAsset(activity.getAssets(), "fonts/droid_naskh.ttf");
            viewHolder.GroupTitle.setTypeface(Naskh);

            v.setTag(viewHolder);
        } else viewHolder = (Holder)v.getTag();

        this.groupItem = this.groupsList.get(groupPosition);

        viewHolder.GroupTitle.setText(this.groupItem);

        return v;
    }

    @Override
    public boolean hasStableIds() {
        return false;
    }

    @Override
    public boolean isChildSelectable(int groupPosition, int childPosition) {
        return true;
    }

    private class Holder {
        public TextView ChildDescription;
        public TextView ChildLocation;
        public TextView ChildTime;
        public TextView ChildDate;
        public TextView ChildAlarmTime;
        public TextView ChildAlarmText;
        public TextView GroupTitle;

    }

}

我不知道为什么，但当我启动应用程序时，孩子们不会出现。 我确认来自适配器主活动的输入值是正确的。

更改此设置

@Override
public int getChildrenCount(int groupPosition) {
    return 0;
}  

为此：

@Override
public int getChildrenCount(int groupPosition) {
    return this.childsList.get(groupPosition)
            .size();
}  

---

您返回了childCount，零，这样您可以看到组，但没有子组。

您将childCount设置为零检查下面的答案当我尝试此操作时，我得到了force closejava.lang.NullPointerExceptionchange answer，使用该选项我尝试了这段代码，但我在getChildrenCount获得了强制关闭java.lang.NullPointerException：help Me您获得了NullPointerException，因为childsList或groupsList为null。检查您是否将它们的值传递给它们