Android UI控件ExpandableListView基本用法详解

<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:paddingBottom="@dimen/activity_vertical_margin" android:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:paddingTop="@dimen/activity_vertical_margin" tools:context="com.smyhvae.expandablelistviewdemo.MainActivity"> <ExpandableListView  android:id="@+id/expandableListView"  android:layout_width="match_parent"  android:layout_height="wrap_content"  /></RelativeLayout> 

<?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="wrap_content"    android:background="#cccccc"    android:orientation="horizontal"> <TextView  android:id="@+id/tv_group"  android:layout_width="wrap_content"  android:layout_height="30dp"  android:gravity="center"  android:text="group text"  android:textColor="#000000"  /></LinearLayout> 

 <?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="wrap_content"    android:gravity="center"    android:orientation="horizontal"> <ImageView  android:id="@+id/iv_child"  android:layout_width="30dp"  android:layout_height="30dp"  android:src="@mipmap/ic_launcher"/> <TextView  android:id="@+id/tv_child"  android:layout_width="match_parent"  android:layout_height="wrap_content"  android:text="item text"  android:textColor="#000000"/></LinearLayout> 

import android.app.Activity;import android.os.Bundle;import android.util.Log;import android.view.View;import android.view.ViewGroup;import android.widget.BaseExpandableListAdapter;import android.widget.ExpandableListView;import android.widget.ImageView;import android.widget.TextView;public class MainActivity extends Activity { //View private ExpandableListView expandableListView; //Model：定义的数据 private String[] groups = {"A", "B", "C"}; //注意，字符数组不要写成{{"A1,A2,A3,A4"}, {"B1,B2,B3,B4，B5"}, {"C1,C2,C3,C4"}} private String[][] childs = {{"A1", "A2", "A3", "A4"}, {"A1", "A2", "A3", "B4"}, {"A1", "A2", "A3", "C4"}}; @Override protected void onCreate(Bundle savedInstanceState) {  super.onCreate(savedInstanceState);  setContentView(R.layout.activity_main);  expandableListView = (ExpandableListView) findViewById(R.id.expandableListView);  expandableListView.setAdapter(new MyExpandableListView()); } //为ExpandableListView自定义适配器 class MyExpandableListView extends BaseExpandableListAdapter {  //返回一级列表的个数  @Override  public int getGroupCount() {   return groups.length;  }  //返回每个二级列表的个数  @Override  public int getChildrenCount(int groupPosition) { //参数groupPosition表示第几个一级列表   Log.d("smyhvae", "-->" + groupPosition);   return childs[groupPosition].length;  }  //返回一级列表的单个item（返回的是对象）  @Override  public Object getGroup(int groupPosition) {   return groups[groupPosition];  }  //返回二级列表中的单个item（返回的是对象）  @Override  public Object getChild(int groupPosition, int childPosition) {   return childs[groupPosition][childPosition]; //不要误写成groups[groupPosition][childPosition]  }  @Override  public long getGroupId(int groupPosition) {   return groupPosition;  }  @Override  public long getChildId(int groupPosition, int childPosition) {   return childPosition;  }  //每个item的id是否是固定？一般为true  @Override  public boolean hasStableIds() {   return true;  }  //【重要】填充一级列表  @Override  public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {   if (convertView == null) {    convertView = getLayoutInflater().inflate(R.layout.item_group, null);   } else {   }   TextView tv_group = (TextView) convertView.findViewById(R.id.tv_group);   tv_group.setText(groups[groupPosition]);   return convertView;  }  //【重要】填充二级列表  @Override  public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView, ViewGroup parent) {   if (convertView == null) {    convertView = getLayoutInflater().inflate(R.layout.item_child, null);   }   ImageView iv_child = (ImageView) convertView.findViewById(R.id.iv_child);   TextView tv_child = (TextView) convertView.findViewById(R.id.tv_child);   //iv_child.setImageResource(resId);   tv_child.setText(childs[groupPosition][childPosition]);   return convertView;  }  //二级列表中的item是否能够被选中？可以改为true  @Override  public boolean isChildSelectable(int groupPosition, int childPosition) {   return true;  } }}