Expandablelistview与CheckBox+setOnCheckedChangeListener有坑
Expandablelistview是用来处理分组数据的（至少我是这么认为的），如QQ列表。那么我们今天主要来说明Expandablelistview+CheckBox的使用情况，以及注意事项。
现来个我的效果图片：
一、布局实现
1、activity_main：
"1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context="com.example.myapplication.MainActivity">
Toolbar
android:id="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary"
android:fitsSystemWindows="true"
app:popupTheme="@style/ThemeOverlay.AppCompat.Light" >
<TextView
android:id="@+id/text_done"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="right"
android:layout_marginRight="5dp"
android:clickable="true"
android:text="Done"
android:textColor="@color/write"
android:textSize="@dimen/textSize"/>
</android.support.v7.widget.Toolbar>
"
android:layout_width=" wrap_content"
android:layout_height="wrap_content"
android:text="To："
android:layout_centerVertical="true"
android:layout_marginLeft="10dp"
android:textColor="@color/write"
android:textSize="17sp"/>
"
android:layout_width=" match_parent"
android:layout_height="match_parent"
android:background="@color/write"
android:layout_toRightOf="@+id/tv"
android:layout_marginRight="10dp"
android:layout_marginTop="8dp"
android:layout_marginBottom="8dp"
android:focusable="true"
android:focusableInTouchMode="true"
android:orientation="horizontal">
"
android:layout_width=" 0dp"
android:layout_height="match_parent"
android:layout_alignParentLeft="true"
android:layout_marginLeft="5dp">
"
android:layout_width=" match_parent"
android:layout_height="match_parent"
android:layout_alignParentRight="true"
android:background="@null"
android:hint="Search..."/>
"
android:layout_width =" fill_parent"
android:layout_height ="wrap_content"
android:groupIndicator="@null"
/>
有点多，只需要最后一个ExpandableListView
2、listitem_child：
"1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<CheckBox
android:id="@+id/checkbox"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="10dp"
android:layout_centerVertical="true"/>
<ImageView
android:id="@+id/iv"
android:layout_width="48dp"
android:layout_height="48dp"
android:layout_marginTop="5dp"
android:layout_marginBottom="5dp"
android:layout_marginLeft="10dp"
android:layout_toRightOf="@+id/checkbox"/>
<TextView
android:id="@+id/name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_toRightOf="@+id/iv"
android:layout_marginTop="5dp"
android:layout_marginLeft="10dp"
android:textStyle="bold"
android:text="aaaaaa"
android:textSize="20sp"/>
<TextView
android:id="@+id/other"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_toRightOf="@+id/iv"
android:layout_below="@+id/name"
android:layout_marginLeft="10dp"
android:text="offline"
android:textSize="18sp"/>
</RelativeLayout>CheckBox是必须的
3、listitem_group：
"1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="30dp"
android:background="#8F8F8F">
<TextView
android:id="@+id/group"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="20sp"
android:layout_centerVertical="true"
android:textColor="@color/write"
android:layout_marginLeft="15dp"
android:text="A"/>
</RelativeLayout>组的显示方式，我这只是一个TextView
二、适配器实现
下面重点来了
package util;
import android.content.Context;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseExpandableListAdapter;
import android.widget.CheckBox;
import android.widget.CompoundButton;
import android.widget.ExpandableListView;
import android.widget.ImageView;
import android.widget.TextView;
import com.example.myapplication.R;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import pojo.People;
/**
* Created by Administrator on 2017/2/24.
*/
public class ExpandableAdapter extends BaseExpandableListAdapter{
public String[] group;
public Map> child;
public List checked;
private Context context;
private boolean cklickgoup;
public ExpandableAdapter(Context context) {
this.context = context;
checked = new ArrayList<>();
if (group == null)
group = new String[]{};
if (child == null)
child = new HashMap>() ;
}
public void setGroups(String[] group)
{
if (group != null)
this.group = group;
}
public void setChild(Map> child)
{
if (child != null)
this.child = child;
}
public void setCklickgoup(boolean cklickgoup)
{
this.cklickgoup = cklickgoup;
}
/ /获取与给定的组相关的数据，得到数组groups中元素的数据
public Object getGroup(int groupPosition) {
return group[groupPosition];
}
//获取与孩子在给定的组相关的数据,得到数组children中元素的数据
public Object getChild(int groupPosition, int childPosition) {
return child.get(group[groupPosition]).get(childPosition);
}
//获取的群体数量，得到groups里元素的个数
public int getGroupCount() {
return group.length;
}
//取得指定组中的children个数，就是groups中每一个条目中的个数
public int getChildrenCount(int groupPosition) {
return child.get(group[groupPosition]).size();
}
//获取组在给定的位置编号，即groups中元素的ID
public long getGroupId(int groupPosition) {
return groupPosition;
}
//获取在给定的组的children的ID，也就是children中元素的ID
public long getChildId(int groupPosition, int childPosition) {
return childPosition;
}
//获取一个视图显示给定组，存放groups
public View getGroupView(int groupPosition, boolean isExpanded, View convertView,
ViewGroup parent) {
View view = convertView;
genericView textView;
if (view == null)
{
view = View.inflate(context, R.layout.listitem_group, null);
textView = new genericView();
view.setTag(textView);
}else
{
textView = (genericView)view.getTag();
}
textView.group = (TextView) view.findViewById(R.id.group);
textView.group.setText(group[groupPosition].toString());
return view;
}
//获取一个视图显示在给定的组 的儿童的数据，就是存放children
public View getChildView(final int groupPosition, final int childPosition, boolean isLastChild,
View convertView, ViewGroup parent) {
View view = convertView;
childView childview;
if (view == null)
{
view = View.inflate(context, R.layout.listitem_child, null);
childview = new childView();
view.setTag(childview);
}else
{
childview = (childView)view.getTag();
}
childview.imageView = (ImageView) view.findViewById(R.id.iv);
childview.name = (TextView) view.findViewById(R.id.name);
childview.checkBox = (CheckBox) view.findViewById(R.id.checkbox);
childview.imageView.setBackgroundResource(child.get(group[groupPosition]).get(childPosition).head);
childview.name.setText(child.get(group[groupPosition]).get(childPosition).name);
childview.checkBox.setChecked(child.get(group[groupPosition]).get(childPosition).isChecked);
childview.checkBox.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
boolean isChecked = child.get(group[groupPosition]).get(childPosition).isChecked;
String name = child.get(group[groupPosition]).get(childPosition).name;
if (!isChecked)
{
child.get(group[groupPosition]).get(childPosition).isChecked = true;
checked.add(child.get(group[groupPosition]).get(childPosition));
}else {
child.get(group[groupPosition]).get(childPosition).isChecked = false;
for (int i =0;i/孩子在指定的位置是可选的，即：children中的元素是可点击的
public boolean isChildSelectable(int groupPosition, int childPosition) {
return true;
}
//表示孩子是否和组ID是跨基础数据的更改稳定
public boolean hasStableIds() {
return true;
}
class genericView
{
public TextView group;
}
class childView
{
public CheckBox checkBox;
public ImageView imageView;
public TextView name;
public TextView other;
}
public interface CheckListener
{
void Checked(List checked);
}
CheckListener CheckListener;
public void getChecked(CheckListener CheckListener)
{
this.CheckListener = CheckListener;
}
} 多选的重点在getChildView方法里面，CheckBox的初始化是用对象里的字段isChecked控制的，每次选择以后就修改isChecked的值就好了，选择结果用的接口回调传递。下面说一下这个地方有个坑，上面代码我用的是CheckBox的setOnClickListener，那么是没问题的，如果你用setOnCheckedChangeListener，那么就很严重了，因为在组的合并展开时可能会触发CheckBox的setOnCheckedChangeListener，为什么是可能会，因为在你CheckBox全部都没选中的时候是不会触发的（注意是全部），一但有选中组的展开就会触发setOnCheckedChangeListener，而且选中状态就会混乱，而且混乱的乱七八糟。
综上所述：Expandablelistview+CheckBox最好不要用setOnCheckedChangeListener