Android中ExpandableListView的使用
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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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