ExpandableListView是android中可以实现下拉list的一个控件,是一个垂直滚动的心事两个级别列表项手风琴试图,列表项是来自ExpandableListViewaAdapter,组可以单独展开。
重要方法:
expandGroup (int groupPos) ;//在分组列表视图中 展开一组, setSelectedGroup (int groupPosition) ;//设置选择指定的组。 setSelectedChild (int groupPosition, int childPosition, boolean shouldExpandGroup);//设置选择指定的子项。 getPackedPositionGroup (long packedPosition);//返回所选择的组 getPackedPositionForChild (int groupPosition, int childPosition) ;//返回所选择的子项 getPackedPositionType (long packedPosition);//返回所选择项的类型(Child,Group) isGroupExpanded (int groupPosition);//判断此组是否展开
expandableListView.setDivider();这个是设定每个Group之间的分割线。
expandableListView.setGroupIndicator();这个是设定每个Group之前的那个图标。
expandableListView.collapseGroup(int group); 将第group组收起
ExpandableListAdapter
一个接口,将基础数据链接到一个ExpandableListView。 此接口的实施将提供访问Child的数据(由组分类),并实例化的Child和Group。
1.重要方法
getChildId (int groupPosition, int childPosition) 获取与在给定组给予孩子相关的数据。
getChildrenCount (int groupPosition) 返回在指定Group的Child数目。
如下案例:

实现这样的效果需要自定义一个Adapter,自定义的Adapter继承BaseExpandableListAdapter,重写getGroupView和
getChildView方法时实例化自己的布局文件就可以了。下面是实现代码:
主布局文件 main.xml
<?xmlversion="1.0"encoding="utf-8"?>
<LinearLayoutxmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical"
android:background="#ffffff"
>
<ExpandableListView
android:id="@+id/elist"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:background="#ffffff"
/>
</LinearLayout>
子视图布局文件 child_layout.xml
<?xmlversion="1.0"encoding="utf-8"?>
<LinearLayoutxmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:paddingLeft="30dp"
>
<ImageView
android:id="@+id/civ"
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:src="@drawable/ren"
android:padding="5dp"
/>
<TextView
android:id="@+id/ctv"
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:padding="5dp"
android:textColor="#000000"
/>
</LinearLayout>
分组视图布局文件 group_layout.xml
<?xmlversion="1.0"encoding="utf-8"?>
<RelativeLayoutxmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/grlayout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<TextView
android:id="@+id/gtv"
android:layout_width="wrap_content"
android:layout_height="fill_parent"
android:paddingLeft="20dp"
android:textColor="#000000"
/>
<ImageView
android:id="@+id/giv"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_centerVertical="true"
android:paddingRight="10dp"
android:src="@drawable/jia"
/>
</RelativeLayout>
自定义适配器 MyElistAdapter.java
publicclass MyElistAdapter extends BaseExpandableListAdapter {
// 分组数据
private String[] group = { "A组", "B组", "C组", "D组" };
private String[][] child = { { "A01", "A02", "A03" },
{ "B01", "B02", "B03" }, { "C01", "C02", "C03" },
{ "D04", "D05", "D06" } };
private Context mContext;
public MyElistAdapter(Context mContext) {
super();
this.mContext = mContext;
}
@Override
public int getGroupCount() {
return group.length;
}
@Override
public int getChildrenCount(int groupPosition) {
return child[groupPosition].length;
}
@Override
public Object getGroup(int groupPosition) {
return group[groupPosition];
}
@Override
public Object getChild(int groupPosition, int childPosition) {
return child[groupPosition][childPosition];
}
@Override
public long getGroupId(int groupPosition) {
return groupPosition;
}
@Override
public long getChildId(int groupPosition, int childPosition) {
returnchildPosition;
}
@Override
public boolean hasStableIds() {
return true;
}
@Override
public View getGroupView(int groupPosition, boolean isExpanded,
View convertView, ViewGroup parent) {
// 实例化布局文件
RelativeLayout glayout = (RelativeLayout) LayoutInflater.from(mContext)
.inflate(R.layout.group_layout, null);
ImageView iv = (ImageView) glayout.findViewById(R.id.giv);
// 判断分组是否展开,分别传入不同的图片资源
if (isExpanded) {
iv.setImageResource(R.drawable.jian);
} else {
iv.setImageResource(R.drawable.jia);
}
TextView tv = (TextView) glayout.findViewById(R.id.gtv);
tv.setText(this.getGroup(groupPosition).toString());
return glayout;
}
@Override
public View getChildView(int groupPosition, int childPosition,
boolean isLastChild, View convertView, ViewGroup parent) {
// 实例化布局文件
LinearLayout clayout = (LinearLayout) LayoutInflater.from(mContext)
.inflate(R.layout.child_layout, null);
TextView tv = (TextView) clayout.findViewById(R.id.ctv);
tv.setText(getChild(groupPosition, childPosition).toString());
return clayout;
}
@Override
public boolean isChildSelectable(int groupPosition, int childPosition) {
return true;
}
}
MainActivity.java
publicclass ExpandableTestActivity extends Activity {
private ExpandableListView elistview;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
elistview = (ExpandableListView) findViewById(R.id.elist);
//这里要把系统自带的图标去掉
elistview.setGroupIndicator(null);
elistview.setAdapter(new ElistAdapter(this));
// elistview.setChildDivider(null);
// elistview.setDivider(null);
}
}
来源:https://www.cnblogs.com/xuewater/archive/2012/08/09/2631021.html