Android中ExpandableListView的使用
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
view plaincopy to clipboardprint? <LinearLayoutandroid:id="@+id/linearLayout"android:layout_width="fill_parent"android:layout_height="fill_parent"androidrientation="vertical"><ExpandableListViewandroid: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
view plaincopy to clipboardprint? privateList<String>groupArray;privateList<List<String>>childArray;
对这两个List进行初始化，并插入一些数据
view plaincopy to clipboardprint? groupArray=newArrayList<String>();childArray=newArrayList<List<String>>();groupArray.add("第一行");groupArray.add("第二行");List<String>tempArray=newArrayList<String>();tempArray.add("第一条");tempArray.add("第二条");tempArray.add("第三条");for(intindex=0;index<groupArray.size();++index){childArray.add(tempArray);}
定义ExpandableListView的Adapter
view plaincopy to clipboardprint? //ExpandableListView的AdapterpublicclassExpandableAdapterextendsBaseExpandableListAdapter{Activityactivity;publicExpandableAdapter(Activitya){activity=a;}publicObjectgetChild(intgroupPosition,intchildPosition){returnchildArray.get(groupPosition).get(childPosition);}publiclonggetChildId(intgroupPosition,intchildPosition){returnchildPosition;}publicintgetChildrenCount(intgroupPosition){returnchildArray.get(groupPosition).size();}publicViewgetChildView(intgroupPosition,intchildPosition,booleanisLastChild,ViewconvertView,ViewGroupparent){Stringstring=childArray.get(groupPosition).get(childPosition);returngetGenericView(string);}//groupmethodstubpublicObjectgetGroup(intgroupPosition){returngroupArray.get(groupPosition);}publicintgetGroupCount(){returngroupArray.size();}publiclonggetGroupId(intgroupPosition){returngroupPosition;}publicViewgetGroupView(intgroupPosition,booleanisExpanded,ViewconvertView,ViewGroupparent){Stringstring=groupArray.get(groupPosition);returngetGenericView(string);}//ViewstubtocreateGroup/Children'sViewpublicTextViewgetGenericView(Stringstring){//LayoutparametersfortheExpandableListViewAbsListView.LayoutParamslayoutParams=newAbsListView.LayoutParams(ViewGroup.LayoutParams.FILL_PARENT,64);TextViewtext=newTextView(activity);text.setLayoutParams(layoutParams);//Centerthetextverticallytext.setGravity(Gravity.CENTER_VERTICAL|Gravity.LEFT);//Setthetextstartingpositiontext.setPadding(36,0,0,0);text.setText(string);returntext;}publicbooleanhasStableIds(){returnfalse;}publicbooleanisChildSelectable(intgroupPosition,intchildPosition){returntrue;}}
最后，给定义好的ExpandableListView添加上Adapter
view plaincopy to clipboardprint? ExpandableListViewexpandableListView=(ExpandableListView)findViewById(R.id.expandableListView);expandableListView.setAdapter(newExpandableAdapter(Main.this));
运行即可见效果~~~
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Android版手风琴(ExpandableListView)
先看效果，过瘾一番。
源码下载：/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) {
intgroupPos =ExpandableListView.getPackedPositionGroup(menuInfo.packedPosition);
intchildPos =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;
}
}
