ExpandableListView的基本用法

package com.example.k.myapplication;import android.content.Context;import android.net.Uri;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.BaseExpandableListAdapter;import android.widget.ExpandableListView;import android.widget.ImageView;import android.widget.TextView;import android.widget.Toast;import com.google.android.gms.appindexing.Action;import com.google.android.gms.appindexing.AppIndex;import com.google.android.gms.common.api.GoogleApiClient;import java.util.ArrayList;import java.util.HashMap;import java.util.List;import java.util.Map;public class MainActivity extends AppCompatActivity {    ExpandableListView mainlistview = null;    List<String> parent = null;    Map<String, List<String>> map = null;    /**     * ATTENTION: This was auto-generated to implement the App Indexing API.     * See https://g.co/AppIndexing/AndroidStudio for more information.     */    private GoogleApiClient client;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        mainlistview = (ExpandableListView) this                .findViewById(R.id.expandableListView);        //为子项设置点击事件        mainlistview.setOnChildClickListener(new ExpandableListView.OnChildClickListener() {            @Override            public boolean onChildClick(ExpandableListView parent, View v, int groupPosition, int childPosition, long id) {                if(groupPosition==0){                    Toast.makeText(MainActivity.this,"第一行第"+childPosition+"个子项被点击",Toast.LENGTH_SHORT).show();                }                if(groupPosition==1){                    Toast.makeText(MainActivity.this,"第二行第"+childPosition+"个子项被点击",Toast.LENGTH_SHORT).show();                }                if(groupPosition==2){                    Toast.makeText(MainActivity.this,"第三行第"+childPosition+"个子项被点击",Toast.LENGTH_SHORT).show();                }                return true;            }        });        initData();        mainlistview.setAdapter(new MyAdapter());        //去掉系统默认的箭头        mainlistview.setGroupIndicator(null);        // ATTENTION: This was auto-generated to implement the App Indexing API.        // See https://g.co/AppIndexing/AndroidStudio for more information.        client = new GoogleApiClient.Builder(this).addApi(AppIndex.API).build();    }    // 初始化数据    public void initData() {        parent = new ArrayList<String>();        parent.add("parent1");        parent.add("parent2");        parent.add("parent3");        map = new HashMap<String, List<String>>();        List<String> list1 = new ArrayList<String>();        list1.add("child1-1");        list1.add("child1-2");        list1.add("child1-3");        map.put("parent1", list1);        List<String> list2 = new ArrayList<String>();        list2.add("child2-1");        list2.add("child2-2");        list2.add("child2-3");        map.put("parent2", list2);        List<String> list3 = new ArrayList<String>();        list3.add("child3-1");        list3.add("child3-2");        list3.add("child3-3");        map.put("parent3", list3);    }    @Override    public void onStart() {        super.onStart();        // ATTENTION: This was auto-generated to implement the App Indexing API.        // See https://g.co/AppIndexing/AndroidStudio for more information.        client.connect();        Action viewAction = Action.newAction(                Action.TYPE_VIEW, // TODO: choose an action type.                "Main Page", // TODO: Define a title for the content shown.                // TODO: If you have web page content that matches this app activity's content,                // make sure this auto-generated web page URL is correct.                // Otherwise, set the URL to null.                Uri.parse("http://host/path"),                // TODO: Make sure this auto-generated app URL is correct.                Uri.parse("android-app://com.example.k.myapplication/http/host/path")        );        AppIndex.AppIndexApi.start(client, viewAction);    }    @Override    public void onStop() {        super.onStop();        // ATTENTION: This was auto-generated to implement the App Indexing API.        // See https://g.co/AppIndexing/AndroidStudio for more information.        Action viewAction = Action.newAction(                Action.TYPE_VIEW, // TODO: choose an action type.                "Main Page", // TODO: Define a title for the content shown.                // TODO: If you have web page content that matches this app activity's content,                // make sure this auto-generated web page URL is correct.                // Otherwise, set the URL to null.                Uri.parse("http://host/path"),                // TODO: Make sure this auto-generated app URL is correct.                Uri.parse("android-app://com.example.k.myapplication/http/host/path")        );        AppIndex.AppIndexApi.end(client, viewAction);        client.disconnect();    }    class MyAdapter extends BaseExpandableListAdapter {        //得到每一项的子View        @Override        public Object getChild(int groupPosition, int childPosition) {            String key = parent.get(groupPosition);            return (map.get(key).get(childPosition));        }        //得到子item的ID        @Override        public long getChildId(int groupPosition, int childPosition) {            return childPosition;        }        //设置子item的组件        @Override        public View getChildView(int groupPosition, int childPosition,                                 boolean isLastChild, View convertView, ViewGroup parent) {            String key = MainActivity.this.parent.get(groupPosition);            String info = map.get(key).get(childPosition);            if (convertView == null) {                LayoutInflater inflater = (LayoutInflater) MainActivity.this                        .getSystemService(Context.LAYOUT_INFLATER_SERVICE);                convertView = inflater.inflate(R.layout.layout_children, null);            }            TextView tv = (TextView) convertView                    .findViewById(R.id.second_textview);            tv.setText(info);            return tv;        }        //获取当前父item下的子item的个数        @Override        public int getChildrenCount(int groupPosition) {            String key = parent.get(groupPosition);            int size = map.get(key).size();            return size;        }        //获取当前父item的数据        @Override        public Object getGroup(int groupPosition) {            return parent.get(groupPosition);        }        @Override        public int getGroupCount() {            return parent.size();        }        @Override        public long getGroupId(int groupPosition) {            return groupPosition;        }        //设置父item组件        @Override        public View getGroupView(int groupPosition, boolean isExpanded,                                 View convertView, ViewGroup parent) {            if (convertView == null) {                LayoutInflater inflater = (LayoutInflater) MainActivity.this                        .getSystemService(Context.LAYOUT_INFLATER_SERVICE);                convertView = inflater.inflate(R.layout.layout_parent, null);            }            TextView tv = (TextView) convertView                    .findViewById(R.id.parent_textview);            tv.setText(MainActivity.this.parent.get(groupPosition));            ImageView i = (ImageView) convertView.findViewById(R.id.imageView);                //当视图处于展开时                if (isExpanded) {                    i.setImageResource(R.drawable.b);                } else {                    //当视图处于关闭时                    i.setImageResource(R.drawable.a);                }            return convertView;        }        @Override        public boolean hasStableIds() {            return true;        }        @Override        public boolean isChildSelectable(int groupPosition, int childPosition) {            return true;        }    }}

布局文件：加入ExpandableListview即可

<ExpandableListView android:layout_height="wrap_content" android:layout_width="wrap_content" android:layout_centerHorizontal="true" android:layout_alignParentTop="true" android:id="@+id/expandableListView"/>