Adapter：
package com.example.websocketchaifen.activity; 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 com.example.websocketchaifen.R; import java.util.List; /** * author : ZJS * e-mail : 15574564770@163.com * date : 20-9-4上午11:25 * desc : * version : 1.0 */ public class myAdapter extends BaseExpandableListAdapter { Context context; LayoutInflater mInflater; String[] mGroupStrings; List<List<Item>> mData; public myAdapter(Context context, List<List<Item>> mData) { this.context = context; this.mData = mData; mInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE); mGroupStrings = new String[]{"第1个", "第2个", "第3个", "第4个"}; } //获取子列表项对应的Item @Override public Item getChild(int groupPosition, int childPosition) { return mData.get(groupPosition).get(childPosition); } @Override public long getChildId(int groupPosition, int childPosition) { return childPosition; } //获得子列表项的数目 @Override public int getChildrenCount(int groupPosition) { return mData.get(groupPosition).size(); } //获得父列表项 @Override public Object getGroup(int groupPosition) { return mData.get(groupPosition); } //获得父列表项的数目 @Override public int getGroupCount() { return mData.size(); } //获得父列表项的Id @Override public long getGroupId(int groupPosition) { return groupPosition; } @Override public boolean hasStableIds() { return false; } //子列表项是否能否触发事件，返回true则为可以响应点击 @Override public boolean isChildSelectable(int groupPosition, int childPosition) { return true; } @Override public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) { if (convertView == null) { convertView = mInflater.inflate(R.layout.group_item_layout, null); } GroupViewHolder holder = new GroupViewHolder(); holder.mGroupName = (TextView) convertView.findViewById(R.id.group_name); holder.mGroupName.setText(mGroupStrings[groupPosition]); holder.mGroupCount = (TextView) convertView.findViewById(R.id.group_number); holder.mGroupCount.setText("[" + mData.get(groupPosition).size() + "]"); return convertView; } @Override public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView, ViewGroup parent) { if (convertView == null) { //如果第一次调用则convertView为null，需要获得对应的layout布局文件：子列表项的布局R.layout.child_item_layout convertView = mInflater.inflate(R.layout.child_item_layout, null); } //子列表项的布局文件的View类，具体看下面的类定义 ChildViewHolder holder = new ChildViewHolder(); holder.mIcon = (ImageView) convertView.findViewById(R.id.img); holder.mChildName = (TextView) convertView.findViewById(R.id.item_name); holder.mChildName.setText(getChild(groupPosition, childPosition).getName()); holder.mDetail = (TextView) convertView.findViewById(R.id.item_detail); holder.mDetail.setText(getChild(groupPosition, childPosition).getDetail()); return convertView; } private class GroupViewHolder { TextView mGroupName; TextView mGroupCount; } private class ChildViewHolder { ImageView mIcon; TextView mChildName; TextView mDetail; } }bean
package com.example.websocketchaifen.activity; /** * author : ZJS * e-mail : 15574564770@163.com * date : 20-9-4上午11:26 * desc : * version : 1.0 */ public class Item { private int resId; //图片（头像）的Id private String name; //子列表项的名字（QQ昵称） private String detail; //子列表项的详细信息（QQ签名） public int getResId() { return resId; } public void setResId(int resId) { this.resId = resId; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getDetail() { return detail; } public void setDetail(String detail) { this.detail = detail; } }main_layout
<?xml version="1.0" encoding="utf-8"?> <androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" tools:context=".activity.ceshi"> <ExpandableListView android:id="@+id/expandableListView" android:layout_width="match_parent" android:layout_height="match_parent" android:layout_weight="1" /> </androidx.constraintlayout.widget.ConstraintLayout>child_item_layout.xml
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical"> <ImageView android:id="@+id/img" android:layout_width="wrap_content" android:layout_height="wrap_content" android:src="@drawable/icon_lx_n" /> <TextView android:text="aaaa" android:id="@+id/item_name" android:layout_width="wrap_content" android:layout_height="wrap_content" /> <TextView android:text="aaaaaaaa" android:id="@+id/item_detail" android:layout_width="wrap_content" android:layout_height="wrap_content" /> </LinearLayout>group_layout
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="horizontal"> <LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_gravity="center_horizontal" android:gravity="center_horizontal" android:orientation="horizontal"> <TextView android:id="@+id/group_name" android:layout_width="0dp" android:layout_height="match_parent" android:layout_weight="1" android:text="AAAA" /> <TextView android:id="@+id/group_number" android:layout_width="0dp" android:layout_height="match_parent" android:layout_weight="1" android:text="AAAA" /> </LinearLayout> </LinearLayout>main_activity
package com.example.websocketchaifen.activity; import androidx.appcompat.app.AppCompatActivity; import android.os.Bundle; import android.widget.ExpandableListView; import com.example.websocketchaifen.R; import java.util.ArrayList; import java.util.List; public class ceshi extends AppCompatActivity { private ExpandableListView listView; private List<List<Item>> data = new ArrayList<>(); private List<Item> mdata = new ArrayList<>(); @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_ceshi); Item item = new Item(); item.setName("A"); item.setDetail("A"); mdata.add(item); for (int i = 0; i < 4; i++) { data.add(mdata); } listView = (ExpandableListView) findViewById(R.id.expandableListView); myAdapter adapter = new myAdapter(this, data); listView.setAdapter(adapter); adapter.notifyDataSetChanged(); } }