Android开发中ExpandableListView的基本用法（总结）

ExpandableListView是一个可折叠的ListView。

效果如下：

思路：

1、创建数据适配器，继承与BaseExpandableListAdapter。（实现相应的重写方法）

2、创建组类(Group)，子项类(Item)。

3、在自定义的MyBaseExpandableListAdapter中创建ViewHolderGroup类，ViewHolderItem类。

4、实现其中的getGroupView( )和getChildView( )方法。（参考之前博文的ListViewAdapter通用模板）

5、设置子列表是否可选中(很重要！！！)，否则点击子项会出错。

    //设置子列表是否可选中(很重要！！！)，否则点击子项会出错
    @Override
    public boolean isChildSelectable(int groupPosition, int childPosition) {
        return true;
    }

6、在MainActivity中调用即可。

代码如下：

MyBaseExpandableListAdapter.java的代码如下：

package com.deepreality.expandablelistviewdemo;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseExpandableListAdapter;
import android.widget.ImageView;
import android.widget.TextView;

import java.util.ArrayList;

public class MyBaseExpandableListAdapter extends BaseExpandableListAdapter {

    private ArrayList<Group> gData;
    private ArrayList<ArrayList<Item>> iData;
    private Context mContext;

    public MyBaseExpandableListAdapter(ArrayList<Group> gData,ArrayList<ArrayList<Item>> iData, Context mContext) {
        this.gData = gData;
        this.iData = iData;
        this.mContext = mContext;
    }

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

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

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

    @Override
    public Object getChild(int groupPosition, int childPosition) {
        return iData.get(groupPosition).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) {
        ViewHolderGroup viewHolderGroup = null;
        if (convertView == null) {
            convertView = LayoutInflater.from(mContext).inflate(R.layout.item_exlist_group, parent, false);
            viewHolderGroup = new ViewHolderGroup(convertView);
            convertView.setTag(viewHolderGroup);
        } else {
            viewHolderGroup = (ViewHolderGroup) convertView.getTag();
        }
        viewHolderGroup.tv_group_name.setText(gData.get(groupPosition).getGroupName());
        return convertView;
    }

    @Override
    public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView, ViewGroup parent) {
        ViewHolderItem viewHolderItem = null;
        if (convertView == null) {
            convertView = LayoutInflater.from(mContext).inflate(R.layout.item_exlist_item, parent, false);
            viewHolderItem = new ViewHolderItem(convertView);
            convertView.setTag(viewHolderItem);
        } else {
            viewHolderItem = (ViewHolderItem) convertView.getTag();
        }
        viewHolderItem.img_icon.setImageResource(iData.get(groupPosition).get(childPosition).getItemImage());
        viewHolderItem.tv_name.setText(iData.get(groupPosition).get(childPosition).getItemName());
        return convertView;
    }

    //设置子列表是否可选中(很重要！！！)，否则点击子项会出错
    @Override
    public boolean isChildSelectable(int groupPosition, int childPosition) {
        return true;
    }

    private static class ViewHolderGroup{
        private TextView tv_group_name;
        public ViewHolderGroup(View convertView) {
            tv_group_name = convertView.findViewById(R.id.tv_group_name);
        }
    }

    private static class ViewHolderItem{
        private ImageView img_icon;
        private TextView tv_name;
        public ViewHolderItem(View convertView) {
            img_icon = convertView.findViewById(R.id.img_icon);
            tv_name = convertView.findViewById(R.id.tv_name);
        }
    }
}

MainActivity.java的代码如下：

package com.deepreality.expandablelistviewdemo;

import android.content.Context;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.ExpandableListView;
import android.widget.Toast;

import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {

    private ArrayList<Group> gData = null;
    private ArrayList<ArrayList<Item>> iData = null;
    private ArrayList<Item> lData = null;
    private Context mContext;
    private ExpandableListView exlist_lol;
    private MyBaseExpandableListAdapter myAdapter = null;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mContext = MainActivity.this;
        exlist_lol = findViewById(R.id.exlist_lol);

        gData = new ArrayList<Group>();
        iData =new ArrayList<ArrayList<Item>>();
        gData.add(new Group("AD"));
        gData.add(new Group("AP"));
        gData.add(new Group("TANK"));

        //AD组
        lData = new ArrayList<Item>();
        lData.add(new Item(R.mipmap.iv_lol_icon3,"剑圣"));
        lData.add(new Item(R.mipmap.iv_lol_icon4,"德莱文"));
        lData.add(new Item(R.mipmap.iv_lol_icon13,"男枪"));
        lData.add(new Item(R.mipmap.iv_lol_icon14,"韦鲁斯"));
        iData.add(lData);

        //AP组
        lData = new ArrayList<Item>();
        lData.add(new Item(R.mipmap.iv_lol_icon1, "提莫"));
        lData.add(new Item(R.mipmap.iv_lol_icon7, "安妮"));
        lData.add(new Item(R.mipmap.iv_lol_icon8, "天使"));
        lData.add(new Item(R.mipmap.iv_lol_icon9, "泽拉斯"));
        lData.add(new Item(R.mipmap.iv_lol_icon11, "狐狸"));
        iData.add(lData);

        //TANK组
        lData = new ArrayList<Item>();
        lData.add(new Item(R.mipmap.iv_lol_icon2, "诺手"));
        lData.add(new Item(R.mipmap.iv_lol_icon5, "德邦"));
        lData.add(new Item(R.mipmap.iv_lol_icon6, "奥拉夫"));
        lData.add(new Item(R.mipmap.iv_lol_icon10, "龙女"));
        lData.add(new Item(R.mipmap.iv_lol_icon12, "狗熊"));
        iData.add(lData);

        myAdapter = new MyBaseExpandableListAdapter(gData, iData, mContext);
        exlist_lol.setAdapter(myAdapter);

        exlist_lol.setOnChildClickListener(new ExpandableListView.OnChildClickListener() {
            @Override
            public boolean onChildClick(ExpandableListView parent, View v, int groupPosition, int childPosition, long id) {
                Toast.makeText(MainActivity.this,iData.get(groupPosition).get(childPosition)
                        .getItemName(),Toast.LENGTH_SHORT).show();
                return true;
            }
        });
    }
}

其他相关的类以及布局xml，请自行定义。