Android开发之ExpandableListView的使用（一目了然版）

 

　　首先，通过ExpandableListView这个名字，我们就可以看得出这是一个可扩展的ListView，对于ListView我们就很清楚，不用太多的解释了！

　　由于本人测试的时候全部都是真机测试的，所以就不上图了，代码尽量详细些。。。

　　(如果大家想测试的话，直接可以把下面的两张图片复制粘贴到你的项目中，其它的代码直接用就ok了)

　　直接看代码讲解吧:

　　

imagetodown.png:

imagetoright.png:

 

MainActivity.java:

package com.example.expandable_test;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.ExpandableListView;
import android.widget.Toast;

public class MainActivity extends Activity {
	private ExpandableListView listView=null;
	private My_Adapter adapter=null;//自定义的适配器
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		
		listView=(ExpandableListView)findViewById(R.id.expandablelistview);
		adapter=new My_Adapter(this);
		listView.setAdapter(adapter);
		
		listView.setOnChildClickListener(new ExpandableListView.OnChildClickListener() {
			@Override
			public boolean onChildClick(ExpandableListView parent, View v,
					int groupPosition, int childPosition, long id) {
				Toast.makeText(MainActivity.this,"你点击了:"+adapter.getChild(groupPosition, childPosition).toString(), Toast.LENGTH_LONG).show();
				return false;
			}
		});
	}
	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		getMenuInflater().inflate(R.menu.main, menu);
		return true;
	}
}

 

然后是自己重写的适配器My_Adapter:

package com.example.expandable_test;

import java.util.ArrayList;
import java.util.List;

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;

public class My_Adapter extends BaseExpandableListAdapter {

    private Context context;
    private LayoutInflater father_Inflater=null;
    private LayoutInflater son_Inflater=null;
    
    private ArrayList<String> father_array;//父层
    private ArrayList<List<String>> son_array;//子层
    
    public My_Adapter(Context context)
    {
        this.context=context;
        father_Inflater=(LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        son_Inflater=(LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        Init_data();
    }

　　//重写的方法，用于获取子层的内容，这里获取子层的显示字符串
    @Override
    public Object getChild(int groupPosition, int childPosition) {
        return son_array.get(groupPosition).get(childPosition);
    }

　　//重写的方法，用于获取子层中单项在子层中的位置
    @Override
    public long getChildId(int groupPosition, int childPosition) {
        return childPosition;
    }

　　//重写的方法，用于获取子层视图
    @Override
    public View getChildView(int groupPosition, int childPosition,
            boolean isLastChild, View convertView, ViewGroup parent) {
        Son_ViewHolder son_ViewHolder=null;
        if(convertView==null)
        {
            convertView=son_Inflater.inflate(R.layout.son, null);
            son_ViewHolder=new Son_ViewHolder();
            son_ViewHolder.son_TextView=(TextView)convertView.findViewById(R.id.son_textview);
            convertView.setTag(son_ViewHolder);
        }
        else
        {
            son_ViewHolder=(Son_ViewHolder)convertView.getTag();
        }
        
        son_ViewHolder.son_TextView.setText(son_array.get(groupPosition).get(childPosition));
        return convertView;
    }

　　//重写的方法，用于获取父层中其中一层的子数目
    @Override
    public int getChildrenCount(int groupPosition) {
        // TODO Auto-generated method stub
        return son_array.get(groupPosition).size();
    }

　　//重写的方法，用于获取父层中的一项，返回的是父层的字符串类型
    @Override
    public Object getGroup(int groupPosition) {
        // TODO Auto-generated method stub
        return father_array.get(groupPosition);
    }

　　//重写的方法，用于获取父层的大小
    @Override
    public int getGroupCount() {
        // TODO Auto-generated method stub
        return father_array.size();
    }

　　//重写的方法，用于获取父层的位置
    @Override
    public long getGroupId(int groupPosition) {
        // TODO Auto-generated method stub
        return groupPosition;
    }

　　//重写的方法，用于获取父层的视图
    @Override
    public View getGroupView(int groupPosition, boolean isExpanded,
            View convertView, ViewGroup parent) {
        // TODO Auto-generated method stub
        Father_ViewHolder father_ViewHolder=null;
        if(convertView==null)
        {
            convertView=father_Inflater.inflate(R.layout.father, null);
            father_ViewHolder=new Father_ViewHolder();
            
            father_ViewHolder.father_TextView=(TextView)convertView.findViewById(R.id.father_textview);
            father_ViewHolder.image_view=(ImageView)convertView.findViewById(R.id.father_imageview);
            
            convertView.setTag(father_ViewHolder);
        }
        else
        {
            father_ViewHolder=(Father_ViewHolder)convertView.getTag();
        }
        father_ViewHolder.father_TextView.setText(father_array.get(groupPosition));
        
        if(isExpanded)
        {
            father_ViewHolder.image_view.setImageDrawable(context.getResources().getDrawable(R.drawable.imagetodown));
        }
        else
        {
            father_ViewHolder.image_view.setImageDrawable(context.getResources().getDrawable(R.drawable.imagetoright));
        }
        return convertView;
    }
　　
　　//....
    @Override
    public boolean hasStableIds() {
        // TODO Auto-generated method stub
        return true;
    }
　　
　　//....
    @Override
    public boolean isChildSelectable(int groupPosition, int childPosition) {
        // TODO Auto-generated method stub
        return true;
    }
   
　　//初始化数据，主要是父层和子层数据的初始化 
    public void Init_data()
    {
        father_array=new ArrayList<String>();
        son_array=new ArrayList<List<String>>();
        
        father_array.add("房产凭证");
        father_array.add("二手汽车");
        father_array.add("二手物品");
        father_array.add("宠物及用品");
        father_array.add("求职简介");
        father_array.add("征婚交友");
        
        List<String> one1=new ArrayList<String>();
        one1.add("郊区");
        one1.add("市区");
        one1.add("农村");
        one1.add("山区");
        one1.add("海湾");
        one1.add("岛屿");
        one1.add("城镇");
        son_array.add(one1);
        
        List<String> two1=new ArrayList<String>();
        two1.add("大众");
        two1.add("奔驰");
        two1.add("QQ");
        two1.add("西门子");
        two1.add("东风");
        son_array.add(two1);
        
        List<String> one2=new ArrayList<String>();
        one2.add("手机");
        one2.add("电脑");
        one2.add("电视");
        one2.add("冰箱");
        one2.add("沙发");
        one2.add("水杯");
        son_array.add(one2);
        
        List<String> two2=new ArrayList<String>();
        two2.add("妞妞");
        two2.add("贝贝");
        two2.add("朵朵");
        two2.add("霍霍");
        two2.add("花花");
        two2.add("美美");
        son_array.add(two2);
        
        List<String> one3=new ArrayList<String>();
        one3.add("教师");
        one3.add("会计");
        one3.add("工程师");
        one3.add("测试员");
        son_array.add(one3);
        
        List<String> two3=new ArrayList<String>();
        two3.add("兴趣交友");
        two3.add("婚庆交友");
        son_array.add(two3);
    }
    public final class Father_ViewHolder
    {
        private TextView father_TextView;
        private ImageView image_view;
    }
    public final class Son_ViewHolder
    {
        private TextView son_TextView;
    }
}

看到适配器的内容，我们就应该很熟悉了，只要是方法实现部分前面有“@Override”的，就都是适配器自身含有的方法，我们所做的不过是重写这些方法进行实现而已！

 

接着，三个布局文件:

1.main.xml

<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"
    tools:context=".MainActivity" >

    <ExpandableListView 
        android:id="@+id/expandablelistview"
        android:layout_width="fill_parent"
         android:drawSelectorOnTop="false"
        android:layout_height="fill_parent"
        android:background="#ffffff"
        android:groupIndicator="@null" 
        android:cacheColorHint="#00000000"
        android:listSelector="#00000000" //这个写出来主要是去除单击单项时点击处变黄一下的效果
        ></ExpandableListView>

</RelativeLayout>

2.father.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="wrap_content"
    android:id="@+id/father"
    android:orientation="vertical"
    > 
    <RelativeLayout 
        android:layout_width="fill_parent"
        android:layout_height="60dp"
        >
        <TextView 
            android:layout_alignParentLeft="true"
            android:textSize="25dp"
            android:id="@+id/father_textview"
　　　　　　　android:layout_centerVertical="true"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            />
        <ImageView 
            android:layout_alignParentRight="true"
            android:layout_centerVertical="true"
            android:id="@+id/father_imageview"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:paddingRight="15dip"
            android:src="@drawable/imagetoright"
            />
    </RelativeLayout>
</LinearLayout>

3.son.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="wrap_content"
    android:id="@+id/son"
    android:orientation="vertical" > 
    <TextView 
		    android:id="@+id/son_textview"
		     android:textSize="25dp"
		    android:layout_width="fill_parent"
		    android:layout_height="50dp"
		    />
</LinearLayout>