android ExpandableListView

ExpandableListView是android中可以实现下拉list的一个控件，是一个垂直滚动的心事两个级别列表项手风琴试图，列表项是来自ExpandableListViewaAdapter，组可以单独展开。

重要方法：

expandGroup (int groupPos) ;//在分组列表视图中 展开一组，
setSelectedGroup (int groupPosition) ;//设置选择指定的组。
 
setSelectedChild (int groupPosition, int childPosition, boolean shouldExpandGroup);//设置选择指定的子项。
 
getPackedPositionGroup (long packedPosition);//返回所选择的组
 
getPackedPositionForChild (int groupPosition, int childPosition) ;//返回所选择的子项
 
getPackedPositionType (long packedPosition);//返回所选择项的类型（Child,Group）
 
isGroupExpanded (int groupPosition);//判断此组是否展开

  expandableListView.setDivider();这个是设定每个Group之间的分割线。

  expandableListView.setGroupIndicator();这个是设定每个Group之前的那个图标。

  expandableListView.collapseGroup(int group); 将第group组收起

ExpandableListAdapter

一个接口，将基础数据链接到一个ExpandableListView。 此接口的实施将提供访问Child的数据（由组分类），并实例化的Child和Group。

1.重要方法

　　　　getChildId (int groupPosition, int childPosition) 获取与在给定组给予孩子相关的数据。

　　　　getChildrenCount (int groupPosition) 返回在指定Group的Child数目。

案例：

首先定义个一个布局文件expandablelistview.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >
     <ExpandableListView
        android:id ="@+id/expandableListView"  
        android:layout_width ="fill_parent"  
        android:layout_height ="wrap_content"  
        >
     </ExpandableListView>
</LinearLayout>

package com.test;
 
import java.util.ArrayList;
import java.util.List;
 
import javax.security.auth.PrivateCredentialPermission;
 
import android.app.Activity;
import android.os.Bundle;
import android.view.Gravity;
import android.view.View;
import android.view.ViewGroup;
import android.view.Window;
import android.widget.AbsListView;
import android.widget.BaseExpandableListAdapter;
import android.widget.ExpandableListView;
import android.widget.TextView;
 
public class ExpandableListViewDemo extends Activity {
    /** Called when the activity is first created. */
     
    //定义两个List用来控制Group和Child中的String;
     
    private  List<String>  groupArray;//组列表
    private  List<List<String>> childArray;//子列表
    private  ExpandableListView  expandableListView_one;
     
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
//        requestWindowFeature(Window.FEATURE_NO_TITLE);  //设置为无标题  
        setContentView(R.layout.expandablelistview);
        expandableListView_one =(ExpandableListView)findViewById(R.id.expandableListView);
        groupArray =new ArrayList<String>();
        childArray = new ArrayList<List<String>>();
        
        /*-第一季-*/
        initdate();
        expandableListView_one.setAdapter(new ExpandableListViewaAdapter(ExpandableListViewDemo.this));
         
        /*-第二季-*/
//        groupArray.add("移动开发");
//        List<String> arrayList = new ArrayList<String>();
//        arrayList.add("Android");
//        arrayList.add("IOS");
//        arrayList.add("Windows Phone");
//        //组循环
//        for(int index=0;index<groupArray.size();++index)
//        {
//          childArray.add(arrayList);
//        }
//        expandableListView_one.setAdapter(new ExpandableListViewaAdapter(ExpandableListViewDemo.this));
         
    }
    class ExpandableListViewaAdapter extends BaseExpandableListAdapter {
        Activity activity;
         public  ExpandableListViewaAdapter(Activity a)  
            {  
                activity = a;  
            }  
       /*-----------------Child */
        @Override
        public Object getChild(int groupPosition, int childPosition) {
            // TODO Auto-generated method stub
            return childArray.get(groupPosition).get(childPosition);
        }
 
        @Override
        public long getChildId(int groupPosition, int childPosition) {
            // TODO Auto-generated method stub
            return childPosition;
        }
 
        @Override
        public View getChildView(int groupPosition, int childPosition,
                boolean isLastChild, View convertView, ViewGroup parent) {
             
            String string =childArray.get(groupPosition).get(childPosition);
             
            return getGenericView(string);
        }
 
        @Override
        public int getChildrenCount(int groupPosition) {
            // TODO Auto-generated method stub
            return childArray.get(groupPosition).size();
        }
       /* ----------------------------Group */
        @Override
        public Object getGroup(int groupPosition) {
            // TODO Auto-generated method stub
            return getGroup(groupPosition);
        }
 
        @Override
        public int getGroupCount() {
            // TODO Auto-generated method stub
            return groupArray.size();
        }
 
        @Override
        public long getGroupId(int groupPosition) {
            // TODO Auto-generated method stub
            return groupPosition;
        }
 
        @Override
        public View getGroupView(int groupPosition, boolean isExpanded,
                View convertView, ViewGroup parent) {
             
           String   string=groupArray.get(groupPosition);
           return getGenericView(string);
        }
 
        @Override
        public boolean hasStableIds() {
            // TODO Auto-generated method stub
            return false;
        }
 
        @Override
        public boolean isChildSelectable(int groupPosition, int childPosition) 
        {
            // TODO Auto-generated method stub
            return true;
        }
         
        private TextView  getGenericView(String string ) 
        {
              AbsListView.LayoutParams  layoutParams =new AbsListView.LayoutParams(
                    ViewGroup.LayoutParams.MATCH_PARENT,
                    ViewGroup.LayoutParams.WRAP_CONTENT);
               
              TextView  textView =new TextView(activity);
              textView.setLayoutParams(layoutParams);
               
              textView.setGravity(Gravity.CENTER_VERTICAL |Gravity.LEFT);
               
              textView.setPadding(40, 0, 0, 0);
              textView.setText(string);
              return textView;
         }
    }
     
    private void initdate() 
    {
        addInfo("语言", new String[]{"Oracle","Java","Linux","Jquery"});
        addInfo("男人的需求", new String[]{"金钱","事业","权力","女人","房子","车","球"});
    }
    private void addInfo(String group,String []child) {
         
        groupArray.add(group);
         
        List<String>  childItem =new ArrayList<String>();
         
        for(int index=0;index<child.length;index++)
        {
            childItem.add(child[index]);
        }
         childArray.add(childItem);
    }
}

运行效果：

案例二：

1.定义一个主界面expandablelistview.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >
     <ExpandableListView 
        android:id ="@+id/expandableListView"  
        android:layout_width ="fill_parent"  
        android:layout_height ="wrap_content"  
        >
     </ExpandableListView>
</LinearLayout>

2.在res/drawable目录下创建样式文件expandablelistview_groups.xml该界面是组界面：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >
     <TextView
        android:id="@+id/textGroup"  
        android:layout_width="fill_parent"  
        android:layout_height="fill_parent"  
        android:paddingLeft="40px"  
        android:paddingTop="6px"  
        android:paddingBottom="6px"  
        android:textSize="15sp"  
        android:text="No data"  
    >   
    </TextView>
</LinearLayout>

3.在res/drawable目录下创建样式文件expandablelistview_child.xml；是子控件，直接显示列表内容

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >
     <TextView    
        android:id="@+id/textChild"  
        android:layout_width="fill_parent"   
        android:layout_height="fill_parent"   
        android:paddingLeft="60px"  
        android:paddingTop="10px"  
        android:paddingBottom="10px"  
        android:textSize="20sp"  
        android:text="No Data" />  
</LinearLayout>

定义java文件：ExpandableListViewDemo_two.java

package com.test;
 
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
 
import javax.security.auth.PrivateCredentialPermission;
 
import com.test.R;
import com.test.ExpandableListViewDemo.ExpandableListViewaAdapter;
import com.test.R.id;
import com.test.R.layout;
 
import android.app.Activity;
import android.os.Bundle;
import android.view.Gravity;
import android.view.View;
import android.view.ViewGroup;
import android.view.Window;
import android.widget.AbsListView;
import android.widget.BaseExpandableListAdapter;
import android.widget.ExpandableListView;
import android.widget.SimpleExpandableListAdapter;
import android.widget.TextView;
 
public class ExpandableListViewDemo_two extends Activity {
    /** Called when the activity is first created. */  
    private  ExpandableListView  expandableListView_one;
    @Override  
    public void onCreate(Bundle savedInstanceState)   
    {   
        super.onCreate(savedInstanceState);   
        setContentView(R.layout.expandablelistview);   
        expandableListView_one =(ExpandableListView)findViewById(R.id.expandableListView);   
        //创建二个一级条目标题    
        Map<String, String> title_1 = new HashMap<String, String>();   
        Map<String, String> title_2 = new HashMap<String, String>();   
            
        title_1.put("group", "移动开发");   
        title_2.put("group", "男人的需求");   
            
        //创建一级条目容器    
        List<Map<String, String>> gruops = new ArrayList<Map<String,String>>();   
            
        gruops.add(title_1);   
        gruops.add(title_2);   
            
        //创建二级条目内容    
            
        //内容一    
        Map<String, String> content_1 = new HashMap<String, String>();   
        Map<String, String> content_2 = new HashMap<String, String>();   
            
        content_1.put("child", "ANDROID");   
        content_2.put("child", "IOS");   
            
        List<Map<String, String>> childs_1 = new ArrayList<Map<String,String>>();   
        childs_1.add(content_1);   
        childs_1.add(content_2);   
            
        //内容二    
        Map<String, String> content_3 = new HashMap<String, String>();   
        Map<String, String> content_4 = new HashMap<String, String>();  
        Map<String, String> content_5 = new HashMap<String, String>(); 
            
        content_3.put("child", "金钱");   
        content_4.put("child", "权力");   
        content_5.put("child", "女人"); 
        List<Map<String, String>> childs_2 = new ArrayList<Map<String,String>>();   
        childs_2.add(content_3);   
        childs_2.add(content_4);  
        childs_2.add(content_5); 
            
        //存放两个内容, 以便显示在列表中    
        List<List<Map<String, String>>> childs = new ArrayList<List<Map<String,String>>>();   
        childs.add(childs_1);   
        childs.add(childs_2);   
            
        //创建ExpandableList的Adapter容器    
/**  
* 使用SimpleExpandableListAdapter显示ExpandableListView  
* 参数1.上下文对象Context  
* 参数2.一级条目目录集合  
* 参数3.一级条目对应的布局文件 （expandablelistview_groups.xml文件 
* 参数4.fromto，就是map中的key，指定要显示的对象  
* 参数5.与参数4对应，指定要显示在groups中的id  
* 参数6.二级条目目录集合  
* 参数7.二级条目对应的布局文件  
* 参数9.与参数8对应，指定要显示在childs中的id  
/           SimpleExpandableListAdapter adapter = new SimpleExpandableListAdapter(   
                this, gruops, R.drawable.expandablelistview_groups, new String[]{"group"}, new int[]{R.id.textGroup},    
                childs, R.drawable.expandablelistview_child, new String[]{"child"}, new int[]{R.id.textChild}   
                );   
            
        //加入列表    
        expandableListView_one.setAdapter(adapter); 
     expandableListView_one.setOnChildClickListener(listener);
    }   
    private OnChildClickListener  listener =new OnChildClickListener() {
   @Override
  public boolean onChildClick(ExpandableListView parent, View v,
    int groupPosition, int childPosition, long id) {
   // TODO Auto-generated method stub
   toast("点击了");
   return false;
  }
 };
 private void toast(String str) {
 Toast.makeText(this, str, Toast.LENGTH_LONG).show(); 
 } 
}

 上面的样式也可以使用系统的自带的样式如下：

android.R.layout.simple_expandable_list_item_1,//层显示样式 ，系统自定义  

android.R.layout.simple_expandable_list_item_2,  

运行效果：

案例三：如果group中有个ImageVIew将会是什么情况呢？

在SimpleExpandableListAdapter中有如下方法：

private void bindView(View view, Map<String, ?> data, String[] from, int[] to) {
        int len = to.length;
 
        for (int i = 0; i < len; i++) {
            TextView v = (TextView)view.findViewById(to[i]);
            if (v != null) {
                v.setText((String)data.get(from[i]));
            }
        }
    }

从上面的方法中可以看出 SimpleExpandableListAdapter把所以的View都当成TextView来处理了，而不像SimpleAdapter可以自动判断View的类型,自动绑定，解决版本就是重写bingview回调一下试试：

public class MyExpandableListAdapter extends BaseExpandableListAdapter{
        private void bindView(View view, Map<String, ?> data, String[] from, int[] to) {
                int len = to.length;
                boolean isBound = false;
                for (int i = 0; i < len; i++) {
                   final View v = view.findViewById(to[i]);
                 if (v!=null) {
                final Object _data = data.get(from[i]);
                String text = _data == null ? "" : data.toString();
                if (text == null) {
                    text = "";
                }
                          if (mViewBinder != null) {//如果Binder不为空,使用Binder进行处理
                                        isBound = mViewBinder.setViewValue(v, data.get(from[i]), text);
                                }
                                if (!isBound) {//如果Binder跳过,使用原来的方法进行处理
                                        TextView _v = (TextView)v;
                                        _v.setText((String)data.get(from[i]));
                                }                               
                        }
                }
        }
}