13.4.创建GroupingCollection

var groupingColl:GroupingCollection = new GroupingCollection();
groupingColl.source = [{city:"Columbus", state:"Ohio", region:"East"},
{city:"Cleveland", state:"Ohio", region:"East"}, {city:"Sacramento",
state:"California", region:"West"}, {city:"Atlanta", state:"Georgia",
region:"South"}];

var groupingInst:Grouping = new Grouping();
groupingInst.fields = [new GroupingField("state")];
groupingColl.grouping = groupingInst;
groupingColl.refresh(false);

<mx:VBox xmlns:mx="http://www.adobe.com/2006/mxml" width="400" height="300" creationComplete="init()">
<mx:Script>
<![CDATA[
import mx.collections.Grouping;
import mx.collections.GroupingField;
import mx.collections.GroupingCollection;
[Bindable]
private var groupingColl:GroupingCollection;
private function init():void {
groupingColl = new GroupingCollection();
groupingColl.source = [
{city:"Columbus",state:"Ohio",region:"East"},
{city:"Cleveland", state:"Ohio", region:"East"},
{city:"Sacramento",state:"California",region:"West"},
{city:"Atlanta",state:"Georgia", region:"South"}];
var groupingInst:Grouping = new Grouping();
groupingInst.fields = [new GroupingField("state")];
groupingColl.grouping = groupingInst;
groupingColl.refresh(false);
}
//设置好GroupingCollection的grouping属性后，设置另外的分组将会覆盖当前分组:
private function createRegionGrouping():void {
var groupingInst:Grouping = new Grouping();
groupingInst.fields =
[new GroupingField("region")];
groupingColl.grouping = groupingInst;
groupingColl.refresh(false);
}

]]>
</mx:Script>
<mx:AdvancedDataGrid dataProvider="{groupingColl}">
<mx:columns>
<mx:AdvancedDataGridColumn dataField="city"/>
</mx:columns>
</mx:AdvancedDataGrid>
<mx:Button click="createRegionGrouping()"/>
</mx:VBox>

groupingInst.fields = [new GroupingField("region"), new GroupingField("state")];