Android之ExpandableListView下拉分组的实现

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?

<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

view plaincopy to clipboardprint?

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

view plaincopy to clipboardprint?

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

view plaincopy to clipboardprint?

//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

view plaincopy to clipboardprint?

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;

}

}