ExpandableListView修改group图标

但是，这种方式做的话，图标不能根据内容调整大小。

二、通过禁用系统自带图标，在group中添加一个ImageView来实现，并通过判断是否有子项来控制是否显示此图标

1、main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android=" http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
    <!-- 禁用系统自带图标android:groupIndicator="@null" -->
<ExpandableListView
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:groupIndicator="@null"
    android:id="@+id/mExpandableListView"
    />
</LinearLayout>
2、group.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
 xmlns:android=" http://schemas.android.com/apk/res/android"
 android:orientation = "horizontal"
 android:layout_width="fill_parent"
 android:layout_height="fill_parent">
 <ImageView
  android:layout_width = "25dip"
  android:layout_height = "25dip"
  android:layout_marginTop="10dip"
  android:id="@+id/mImageView"
  />
 <TextView
  android:id = "@+id/group_tv"
  android:layout_width = "wrap_content"
  android:layout_height = "wrap_content"
  android:paddingLeft = "30px"
  android:paddingBottom = "10px"
  android:textSize = "26sp"/>
</LinearLayout>

3、child.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
 xmlns:android=" http://schemas.android.com/apk/res/android"
 android:orientation = "horizontal"
 android:layout_width="match_parent"
 android:layout_height="match_parent">
 <ImageView
  android:layout_gravity = "center_vertical"
  android:id = "@+id/child_iv"
  android:layout_width = "70px"
  android:layout_height = "70px"
  android:paddingLeft = "30px"
  android:paddingTop = "2px"
  android:paddingBottom = "5px"
  android:src = "@drawable/icon"/>
 <TextView
  android:layout_gravity = "center_vertical"
  android:id = "@+id/child_tv"
  android:layout_width = "fill_parent"
  android:layout_height = "fill_parent"
  android:paddingLeft = "30px"
  android:paddingTop = "10px"
  android:paddingBottom = "5px"
  android:textSize = "30sp"/>
</LinearLayout>

4、activity代码

package test.expandableListView;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import android.app.Activity;
import android.content.Context;
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.LinearLayout;
import android.widget.TextView;

public class TestExpandableListView extends Activity
{
 @Override
 public void onCreate(Bundle savedInstanceState)
 {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.main);
  ExpandableListView elv = (ExpandableListView)findViewById(R.id.mExpandableListView);

//准备一级列表中显示的数据:2个一级列表,分别显示"group1"和"group2"
  List<Map<String, String>> groups = new ArrayList<Map<String, String>>();
  Map<String, String> group1 = new HashMap<String, String>();
  group1.put("group", "group1");
  Map<String, String> group2 = new HashMap<String, String>();
  group2.put("group", "group2");
  groups.add(group1);
  groups.add(group2);

//准备第一个一级列表中的二级列表数据:两个二级列表,分别显示"childData1"和"childData2"
  List<Map<String, String>> child1 = new ArrayList<Map<String, String>>();
  Map<String, String> child1Data1 = new HashMap<String, String>();
  child1Data1.put("child", "child1Data1");
  Map<String, String> child1Data2 = new HashMap<String, String>();
  child1Data2.put("child", "child1Data2");
  child1.add(child1Data1);
  child1.add(child1Data2);

//准备第二个一级列表中的二级列表数据:一个二级列表,显示"child2Data1"
  List<Map<String, String>> child2 = new ArrayList<Map<String, String>>();
  Map<String, String> child2Data1 = new HashMap<String, String>();
  child2Data1.put("child", "child2Data1");
  child2.add(child2Data1);

//用一个list对象保存所有的二级列表数据
  List<List<Map<String, String>>> childs = new ArrayList<List<Map<String, String>>>();
  childs.add(child1);
  childs.add(child2);

ExpandableAdapter viewAdapter = new ExpandableAdapter(this, groups, childs);
  elv.setAdapter(viewAdapter);
 }

//自定义的ExpandListAdapter
 class ExpandableAdapter extends BaseExpandableListAdapter
 {
  private Context context;
  List<Map<String, String>> groups;
  List<List<Map<String, String>>> childs;

/*
   * 构造函数:
   * 参数1:context对象
   * 参数2:一级列表数据源
   * 参数3:二级列表数据源
   */
  public ExpandableAdapter(Context context, List<Map<String, String>> groups, List<List<Map<String, String>>> childs)
  {
   this.groups = groups;
   this.childs = childs;
   this.context = context;
  }

public Object getChild(int groupPosition, int childPosition)
  {
   return childs.get(groupPosition).get(childPosition);
  }

public long getChildId(int groupPosition, int childPosition)
  {
   return childPosition;
  }

//获取二级列表的View对象
  public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView,
    ViewGroup parent)
  {
   @SuppressWarnings("unchecked")
   String text = ((Map<String, String>) getChild(groupPosition, childPosition)).get("child");
   LayoutInflater layoutInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);

//获取二级列表对应的布局文件, 并将其各元素设置相应的属性
   LinearLayout linearLayout = (LinearLayout) layoutInflater.inflate(R.layout.child, null);
   TextView tv = (TextView) linearLayout.findViewById(R.id.child_tv);
   tv.setText(text);
   ImageView imageView = (ImageView)linearLayout.findViewById(R.id.child_iv);
   imageView.setImageResource(R.drawable.icon);

return linearLayout;
  }

public int getChildrenCount(int groupPosition)
  {
   return childs.get(groupPosition).size();
  }

public Object getGroup(int groupPosition)
  {
   return groups.get(groupPosition);
  }

public int getGroupCount()
  {
   return groups.size();
  }

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

//获取一级列表View对象
  public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent)
  {
   String text = groups.get(groupPosition).get("group");
   LayoutInflater layoutInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);

//获取一级列表布局文件,设置相应元素属性
   LinearLayout linearLayout = (LinearLayout) layoutInflater.inflate(R.layout.group, null);
   TextView textView = (TextView)linearLayout.findViewById(R.id.group_tv);
   textView.setText(text);
   
   ImageView imageView = (ImageView) linearLayout.findViewById(R.id.mImageView);
   
   if(getChildrenCount(groupPosition) == 0){//该组下没有子项
    imageView.setVisibility(View.GONE);
   }else{
    if(isExpanded == true){//展开状态
     imageView.setImageResource(R.drawable.xiala);
    }else{//收起状态
     imageView.setImageResource(R.drawable.shouqi);
    }
   }

return linearLayout;
  }

public boolean hasStableIds()
  {
   return false;
  }

public boolean isChildSelectable(int groupPosition, int childPosition)
  {
   return false;
  }

}
}

截图：