Android之ExpandableListView下拉分组的实现

xiangzhihong

发布于 2018-01-26 20:27:11

7360

发布于 2018-01-26 20:27:11

文章被收录于专栏：向治洪向治洪

ExpandableListView是android中可以实现下拉list的一个控件，具体的实现方法如下：

首先：在layout的xml文件中定义一个ExpandableListView

<LinearLayout 
 android:id="@+id/linearLayout" 
 android:layout_width="fill_parent" 
 android:layout_height="fill_parent" 
 androidrientation="vertical" 
 > 
 
 <ExpandableListView 
 android:id="@+id/expandableListView" 
 android:layout_width="fill_parent" 
 android:layout_height="wrap_content" 
 /> 
</LinearLayout>

定义两个List，用来存放控件中Group/Child中的String

private?List<String>?groupArray;??
private?List<List<String>>?childArray;??

对这两个List进行初始化，并插入一些数据

groupArray?=?new?ArrayList<String>();??
childArray?=?new?ArrayList<List<String>>();??
 
groupArray.add("第一行");??
groupArray.add("第二行");??
 
List<String>?tempArray?=?new?ArrayList<String>();??
tempArray.add("第一条");??
tempArray.add("第二条");??
tempArray.add("第三条");??
 
for(int?index?=?0;?index?<groupArray.size();?++index)??
{??
????childArray.add(tempArray);??
}??

定义ExpandableListView的Adapter


//ExpandableListView的Adapter 
public class?ExpandableAdapter?extends?BaseExpandableListAdapter??
{??
????Activity?activity;??
 
 public?ExpandableAdapter(Activity?a)??
????{??
????????activity?=?a;??
????}??
 public?Object?getChild(int?groupPosition,?int?childPosition)??
????{??
 return?childArray.get(groupPosition).get(childPosition);??
????}??
 public long?getChildId(int?groupPosition,?int?childPosition)??
????{??
 return?childPosition;??
????}??
 public int?getChildrenCount(int?groupPosition)??
????{??
 return?childArray.get(groupPosition).size();??
????}??
 public?View?getChildView(int?groupPosition,?int?childPosition,??
 boolean?isLastChild,?View?convertView,?ViewGroup?parent)??
????{??
????????String?string?=?childArray.get(groupPosition).get(childPosition);??
 return?getGenericView(string);??
????}??
 //?group?method?stub 
 public?Object?getGroup(int?groupPosition)??
????{??
 return?groupArray.get(groupPosition);??
????}??
 public int?getGroupCount()??
????{??
 return?groupArray.size();??
????}??
 public long?getGroupId(int?groupPosition)??
????{??
 return?groupPosition;??
????}??
 public?View?getGroupView(int?groupPosition,?boolean?isExpanded,??
????????????View?convertView,?ViewGroup?parent)??
????{??
????????String?string?=?groupArray.get(groupPosition);??
 return?getGenericView(string);??
????}??
 //?View?stub?to?create?Group/Children?'s?View 
 public?TextView?getGenericView(String?string)??
????{??
 //?Layout?parameters?for?the?ExpandableListView 
????????AbsListView.LayoutParams?layoutParams?=?new?AbsListView.LayoutParams(??
????????????????ViewGroup.LayoutParams.FILL_PARENT,?64);??
????????TextView?text?=?new?TextView(activity);??
????????text.setLayoutParams(layoutParams);??
 //?Center?the?text?vertically 
????????text.setGravity(Gravity.CENTER_VERTICAL?|?Gravity.LEFT);??
 //?Set?the?text?starting?position 
????????text.setPadding(36,?0,?0,?0);??
????????text.setText(string);??
 return?text;??
????}??
 public boolean?hasStableIds()??
????{??
 return false;??
????}??
 public boolean?isChildSelectable(int?groupPosition,?int?childPosition)??
????{??
 return true;??
????}??
}??

最后，给定义好的ExpandableListView添加上Adapter

ExpandableListView?expandableListView?=?(ExpandableListView)findViewById(R.id.expandableListView);??
expandableListView.setAdapter(new?ExpandableAdapter(Main.this));??

运行即可见效果~~~

----------------------------------------------------------------------------------------------------------------

Android版手风琴(ExpandableListView)

先看效果，过瘾一番。

?源码下载：http://files.cnblogs.com/salam/WidgetDemo.rar

　　ExpandableListView是Android中的手风琴，本人感觉效果相当棒。

　　一、ExpandableListView介绍

　　　　一个垂直滚动的显示两个级别（Child,Group）列表项的视图，列表项来自ExpandableListAdapter 。组可以单独展开。

　　1.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

　　2.代码：

ExpandableListContextMenuInfo menuInfo=(ExpandableListContextMenuInfo)item.getMenuInfo();
 ??String title=((TextView)menuInfo.targetView).getText().toString();
 ??int type=ExpandableListView.getPackedPositionType(menuInfo.packedPosition);
 
 ??if (type==ExpandableListView.PACKED_POSITION_TYPE_CHILD) {
 ??int?groupPos =ExpandableListView.getPackedPositionGroup(menuInfo.packedPosition);
 ??int?childPos =ExpandableListView.getPackedPositionChild(menuInfo.packedPosition);

二、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。

　　2.代码

?public class MyExpandableListAdapter extends BaseExpandableListAdapter {
 ???????? // Sample data set.? children[i] contains the children (String[]) for groups[i].
 ???????? public String[] groups = { "我的好友", "新疆同学", "亲戚", "同事" };
 ???????? public String[][] children = {
 ???????????????? { "胡算林", "张俊峰", "王志军", "二人" },
 ???????????????? { "李秀婷", "蔡乔", "别高", "余音" },
 ???????????????? { "摊派新", "张爱明" },
 ???????????????? { "马超", "司道光" }
 ???????? };
 
 ???????? public Object getChild(int groupPosition, int childPosition) {
 ???????????? return children[groupPosition][childPosition];
 ???????? }
???????? public long getChildId(int groupPosition, int childPosition) {
 ???????????? return childPosition;
 ???????? }
???????? public int getChildrenCount(int groupPosition) {
 ???????????? return children[groupPosition].length;
 ???????? }
???????? public TextView getGenericView() {
 ???????????? // Layout parameters for the ExpandableListView
 ???????????? AbsListView.LayoutParams lp = new AbsListView.LayoutParams(
 ???????????????????? ViewGroup.LayoutParams.MATCH_PARENT, 64);
???????????? TextView textView = new TextView(ExpandableListDemo.this);
 ???????????? textView.setLayoutParams(lp);
 ???????????? // Center the text vertically
 ???????????? textView.setGravity(Gravity.CENTER_VERTICAL | Gravity.LEFT);
 ???????????? // Set the text starting position
 ???????????? textView.setPadding(36, 0, 0, 0);
 ???????????? return textView;
 ???????? }
 
 ???????? public View getChildView(int groupPosition, int childPosition, boolean isLastChild,
 ???????????????? View convertView, ViewGroup parent) {
 ???????????? TextView textView = getGenericView();
 ???????????? textView.setText(getChild(groupPosition, childPosition).toString());
 ???????????? return textView;
 ???????? }
???????? public Object getGroup(int groupPosition) {
 ???????????? return groups[groupPosition];
 ???????? }
???????? public int getGroupCount() {
 ???????????? return groups.length;
 ???????? }
???????? public long getGroupId(int groupPosition) {
 ???????????? return groupPosition;
 ???????? }
???????? public View getGroupView(int groupPosition, boolean isExpanded, View convertView,
 ???????????????? ViewGroup parent) {
 ???????????? TextView textView = getGenericView();
 ???????????? textView.setText(getGroup(groupPosition).toString());
 ???????????? return textView;
 ???????? }
???????? public boolean isChildSelectable(int groupPosition, int childPosition) {
 ???????????? return true;
 ???????? }
???????? public boolean hasStableIds() {
 ???????????? return true;
 ???????? }
???? }

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