2014最后一篇，记ExpandableListViewd的自定义

首先看下效果图，看着效果一步一步实现它

说先是两个布局，一个是group_item_layout.xml，是一级项的布局，一个是child_item_layout.xml，是二级项的布局

<?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="40dp"    android:orientation="horizontal">    <TextView        android:id="@+id/group_name"        android:layout_width="wrap_content"        android:layout_height="40dp"        android:layout_marginLeft="35dip"        android:gravity="center_vertical" />    <TextView        android:id="@+id/group_count"        android:layout_width="wrap_content"        android:layout_height="40dp"        android:layout_marginLeft="5dip"        android:gravity="center_vertical" /></LinearLayout>

一级项里就只有两个TextView，一个用于显示标题，一个用于显示该一级项下有几个二级项

<?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="wrap_content"    android:descendantFocusability="blocksDescendants"    android:minHeight="40dp"    android:orientation="horizontal">    <!--android:descendantFocusability="blocksDescendants"如果不设置子项将不能点击-->    <ImageButton        android:id="@+id/img"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_gravity="center_vertical"        android:layout_marginLeft="2dip"        android:layout_marginRight="10dip" />    <RelativeLayout        android:layout_width="wrap_content"        android:layout_height="match_parent">        <TextView            android:id="@+id/item_name"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:layout_alignParentTop="true" />        <TextView            android:id="@+id/item_detail"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:layout_alignParentBottom="true"            android:layout_marginTop="10dp" />    </RelativeLayout></LinearLayout>

二级项里面有一个图片在最前面显示，然后是两个TextView，一个显示标题，一个显示描述.

然后是主布局，activity_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/expand_listview"        android:layout_width="match_parent"        android:layout_height="match_parent">    </ExpandableListView></RelativeLayout>

主布局里就一个ExpanableListView

编写Group和Child对应的Item实体类

package cn.edu.zafu.expand;public class GroupItem {    private String name;    public GroupItem(String name) {        this.name = name;    }    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }}

package cn.edu.zafu.expand;public class ChildItem {    private int resId;    private String name;    private String detail;    public ChildItem(int resId, String name, String detail) {        this.resId = resId;        this.name = name;        this.detail = detail;    }    public int getResId() {        return resId;    }    public void setResId(int resId) {        this.resId = resId;    }    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }    public String getDetail() {        return detail;    }    public void setDetail(String detail) {        this.detail = detail;    }}

最重要的一步就是适配器了

package cn.edu.zafu.expand;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;import java.util.List;public class MyBaseExpandableListAdapter extends BaseExpandableListAdapter {    private Context mContext = null;    private LayoutInflater mInflater = null;    private List<GroupItem> mGroup = null;    private List<List<ChildItem>> mChild = null;    public MyBaseExpandableListAdapter(Context context, List<GroupItem> group, List<List<ChildItem>> child) {        mContext = context;        mGroup = group;        mChild = child;        mInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);    }    @Override    public int getGroupCount() {        return mGroup.size();    }    @Override    public int getChildrenCount(int groupPosition) {        return mChild.get(groupPosition).size();    }    @Override    public List<ChildItem> getGroup(int groupPosition) {        return mChild.get(groupPosition);    }    @Override    public ChildItem getChild(int groupPosition, int childPosition) {        return mChild.get(groupPosition).get(childPosition);    }    @Override    public long getGroupId(int groupPosition) {        return groupPosition;    }    @Override    public long getChildId(int groupPosition, int childPosition) {        return childPosition;    }    @Override    public boolean hasStableIds() {        return false;    }    @Override    public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {        View view = null;        GroupViewHolder viewHolder = null;        if (convertView == null) {            view = mInflater.inflate(R.layout.group_item_layout, null);            viewHolder = new GroupViewHolder();            viewHolder.mGroupName = (TextView) view.findViewById(R.id.group_name);            viewHolder.mGroupCount = (TextView) view.findViewById(R.id.group_count);            view.setTag(viewHolder);        } else {            view = convertView;            viewHolder = (GroupViewHolder) view.getTag();        }        viewHolder.mGroupName.setText(mGroup.get(groupPosition).getName());        viewHolder.mGroupCount.setText("[" + mChild.get(groupPosition).size() + "]");        return view;    }    @Override    public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView, ViewGroup parent) {        View view = null;        ChildViewHolder viewHolder = null;        if (convertView == null) {            view = mInflater.inflate(R.layout.child_item_layout, null);            viewHolder = new ChildViewHolder();            viewHolder.mIcon = (ImageView) view.findViewById(R.id.img);            viewHolder.mChildName = (TextView) view.findViewById(R.id.item_name);            viewHolder.mDetail = (TextView) view.findViewById(R.id.item_detail);            view.setTag(viewHolder);        } else {            view = convertView;            viewHolder = (ChildViewHolder) view.getTag();        }        viewHolder.mIcon.setBackgroundResource(getChild(groupPosition, childPosition).getResId());        viewHolder.mChildName.setText(getChild(groupPosition, childPosition).getName());        viewHolder.mDetail.setText(getChild(groupPosition, childPosition).getDetail());        return view;    }    @Override    public boolean isChildSelectable(int groupPosition, int childPosition) {        return true;    }    private class GroupViewHolder {        TextView mGroupName;        TextView mGroupCount;    }    private class ChildViewHolder {        ImageView mIcon;        TextView mChildName;        TextView mDetail;    }}

适配器的关键点事继承BaseExpandableListAdapter，并覆盖重写里面的抽象方法

最后是Activity的代码，具体见注释

package cn.edu.zafu.expand;import android.app.Activity;import android.os.Bundle;import android.view.View;import android.widget.ExpandableListView;import android.widget.Toast;import java.util.ArrayList;import java.util.List;public class MainActivity extends Activity {    private ExpandableListView mExpandableListView = null;    private MyBaseExpandableListAdapter mAdapter = null;    private List<GroupItem> mGroup = new ArrayList<GroupItem>();    private List<List<ChildItem>> mChild = new ArrayList<List<ChildItem>>();    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        initData();//初始化数据        mExpandableListView = (ExpandableListView) findViewById(R.id.expand_listview);        //mExpandableListView.setGroupIndicator(null);//前面的指示器设为无        mAdapter = new MyBaseExpandableListAdapter(this, mGroup, mChild);//新建适配器        mExpandableListView.setAdapter(mAdapter);//设置适配器        mExpandableListView.setOnGroupClickListener(new MyOnGroupClickListener());//设置Group点击监听        mExpandableListView.setOnChildClickListener(new MyOnChildClickListener());//设置Child点击监听    }    /*    数据初始化     */    private void initData() {        GroupItem groupItem = null;        groupItem = new GroupItem("我的设备");        mGroup.add(groupItem);        groupItem = new GroupItem("我的好友");        mGroup.add(groupItem);        groupItem = new GroupItem("陌生人");        mGroup.add(groupItem);        List<ChildItem> child = null;        ChildItem childItem = null;        child = new ArrayList<ChildItem>();        childItem = new ChildItem(R.drawable.expland_child_item, "我的电脑", "[在线]无需数据线，手机轻松传文件到电脑");        child.add(childItem);        childItem = new ChildItem(R.drawable.expland_child_item, "我的打印机", "将手机文件或照片发送到电脑连接的打印机");        child.add(childItem);        mChild.add(child);        child = new ArrayList<ChildItem>();        childItem = new ChildItem(R.drawable.expland_child_item, "羽人", "[在线]过去哪都不重要");        child.add(childItem);        childItem = new ChildItem(R.drawable.expland_child_item, "梦想逝去", "[在线]后来我眼瞎了");        child.add(childItem);        childItem = new ChildItem(R.drawable.expland_child_item, "啊飒飒", "[离线请留言]");        child.add(childItem);        mChild.add(child);        child = new ArrayList<ChildItem>();        childItem = new ChildItem(R.drawable.expland_child_item, "话说撒", "[在线]自行车自行车XC");        child.add(childItem);        childItem = new ChildItem(R.drawable.expland_child_item, "法规发生的变成", "[在线]啊实打实大学");        child.add(childItem);        childItem = new ChildItem(R.drawable.expland_child_item, "的感受到", "[离线请留言]");        child.add(childItem);        mChild.add(child);    }    /*    一级事件监听    */    class MyOnGroupClickListener implements ExpandableListView.OnGroupClickListener {        @Override        public boolean onGroupClick(ExpandableListView parent, View v, int groupPosition, long id) {            int count = mAdapter.getChildrenCount(groupPosition);            Toast.makeText(getApplicationContext(), "拥有的子类个数:" + count, Toast.LENGTH_SHORT).show();            return false;//返回false能继续处理展开动作，如果返回了true，则二级项不能展开        }    }    /*     二级事件监听     */    class MyOnChildClickListener implements ExpandableListView.OnChildClickListener {        @Override        public boolean onChildClick(ExpandableListView parent, View v, int groupPosition, int childPosition, long id) {            ChildItem item = mAdapter.getChild(groupPosition, childPosition);            Toast.makeText(getApplicationContext(), "你点击了" + item.getName(), Toast.LENGTH_SHORT).show();            return true;//事件被处理了返回true不能继续处理事件        }    }}

整个流程下来可能二级项会出现不能点击的情况，这时候需要将二级项的布局文件里的所有Layout里增加属性，我这里只是增加了根layout，内部layout并没有增加，发现这样后也是可以点击的，于是内部layout就没有加这个属性了

android:descendantFocusability="blocksDescendants"

同时适配器里的方法isChildSelectedable要返回true

 @Override    public boolean isChildSelectable(int groupPosition, int childPosition) {        return true;    }