ExpandableListView

以前学习ListView的时候就经常要用到自定义适配器的ListView, 这两天看到Mars老师的ExpandableListView教学视频, 但只讲到了最基本使用. 并没有讲到如何定义自己的ExpandableListView, 于是就想类比以前的ListView, 自己定义一个Adapter. 下面就是程序了, 其实只是实现了最基本的自定义, 如果网友有需要, 完全可以定义属于自己的更炫的界面效果. 代码已添加了简单注释, 如有疑问, 可以留言提出.
如有不足, 欢迎拍砖!

废话不多说, 先上图:



再上代码:

main.xml:定义Activity的界面布局:

<?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"

>

<ExpandableListView

android:id = "@+id/expandableListView"

android:layout_width = "fill_parent"

android:layout_height = "fill_parent"

android:drawSelectorOnTop = "false"/>

</LinearLayout>

group.xml:定义一级列表的布局方式:

<?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">

<TextView

android:id = "@+id/textView01"

android:layout_width = "match_parent"

android:layout_height = "match_parent"

android:paddingLeft = "60px"

android:paddingTop = "10px"

android:paddingBottom = "10px"

android:textSize = "26sp"/>

</LinearLayout>

复制代码

child.xml:定义二级列表的布局方式:

<?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/imageView01"

android:layout_width = "70px"

android:layout_height = "70px"

android:paddingLeft = "30px"

android:paddingTop = "2px"

android:paddingBottom = "5px"

android:src = "@drawable/abc"/>

<TextView

android:layout_gravity = "center_vertical"

android:id = "@+id/childTo"

android:layout_width = "match_parent"

android:layout_height = "match_parent"

android:paddingLeft = "30px"

android:paddingTop = "10px"

android:paddingBottom = "5px"

android:textSize = "30sp"/>

</LinearLayout>

ExpandableList.java

package snowfox.expandable;

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 ExpandableList extends Activity

{

@Override

public void onCreate(Bundle savedInstanceState)

{

super.onCreate(savedInstanceState);

setContentView(R.layout.main);

ExpandableListView elv = (ExpandableListView)findViewById(R.id.expandableListView);

//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;

public ExpandableAdapter(Context context, List<Map<String, String>> groups, List<List<Map<String, String>>> childs)

{

this.groups = groups;

this.childs = childs;

this.context = context;

}

@Override

public Object getChild(int groupPosition, int childPosition)

{

return childs.get(groupPosition).get(childPosition);

}

@Override

public long getChildId(int groupPosition, int childPosition)

{

return childPosition;

}

//获取二级列表的View对象

@Override

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.childTo);

tv.setText(text);

ImageView imageView = (ImageView)linearLayout.findViewById(R.id.imageView01);

imageView.setImageResource(R.drawable.abc);

return linearLayout;

}

@Override

public int getChildrenCount(int groupPosition)

{

return childs.get(groupPosition).size();

}

@Override

public Object getGroup(int groupPosition)

{

return groups.get(groupPosition);

}

@Override

public int getGroupCount()

{

return groups.size();

}

@Override

public long getGroupId(int groupPosition)

{

return groupPosition;

}

//获取一级列表View对象

@Override

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.textView01);

textView.setText(text);

return linearLayout;

}

@Override

public boolean hasStableIds()

{

return false;

}

@Override

public boolean isChildSelectable(int groupPosition, int childPosition)

{

return false;

}

}

}