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>
<?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;
}
