Flex 3 发现之旅:AdvancedDataGrid的使用(第三部分)续2

对分层数据进行列分组

和扁平数据一样，您使用分层数据进行列分组，以下例子修改自“为导航树创建单独的列“章节中的示例以将Actual和Estimates列归组到Revenues组列中：

 version="1.0" encoding="utf-8"?>
 xmlns:mx="">
 >
    import mx.collections.ArrayCollection;
  include "SimpleHierarchicalData.as";
  ]]>
 >
  width="100%" height="100%">
  >
    source="{dpHierarchy}"/>
  >
  >
   dataField="Region"/>
    dataField="Territory_Rep"
    headerText="Territory Rep"/>
    headerText="Revenues">
     dataField="Actual"/>
     dataField="Estimate"/>
   >
  >
 >
>

上面的列分组示例中并没有为AdvancedDataGridColumnGroup类指定数据字段，但是，AdvancedDataGridColumnGroup类就是被设计用于和分层数据一起工作的。因此，如果您给AdvancedDataGridColumnGroup类指定一个数据字段的话，它将自动给该数据字段的子字段创建一个列分组。

在下面示例中，HierarchicalDataForGroupedColumns.as文件定义了一个分层数据，设置Revenues字段包含俩个子字段，Actual 和Estimate：

[Bindable]
private var dpHierarchy:ArrayCollection = new ArrayCollection([
 {Region:"Southwest", Territory:"Arizona",
  Territory_Rep:"Barbara Jennings",
  Revenues:{Actual:38865, Estimate:40000}},
 {Region:"Southwest", Territory:"Arizona",
  Territory_Rep:"Dana Binn",
  Revenues:{Actual:29885, Estimate:30000}},
 {Region:"Southwest", Territory:"Central California",
  Territory_Rep:"Joe Smith",
  Revenues:{Actual:29134, Estimate:30000}},
 {Region:"Southwest", Territory:"Nevada",
  Territory_Rep:"Bethany Pittman",
  Revenues:{Actual:52888, Estimate:45000}},
 {Region:"Southwest", Territory:"Northern California",
  Territory_Rep:"Lauren Ipsum",
  Revenues:{Actual:38805, Estimate:40000}},
 {Region:"Southwest", Territory:"Northern California",
  Territory_Rep:"T.R. Smith",
  Revenues:{Actual:55498, Estimate:40000}},
 {Region:"Southwest", Territory:"Southern California",
  Territory_Rep:"Alice Treu",
  Revenues:{Actual:44985, Estimate:45000}},
 {Region:"Southwest", Territory:"Southern California",
  Territory_Rep:"Jane Grove",
  Revenues:{Actual:44913, Estimate:45000}}
]);

下面示例使用该数据并且指定Revenues字段为AdvancedDataGridColumnGroup.dataField属性的值，其输出如下：

以下是实现代码：

 version="1.0" encoding="utf-8"?>
 xmlns:mx="">
 >
     import mx.collections.ArrayCollection;
   include "HierarchicalDataForGroupedColumns.as";
  ]]>
 >
  id="myADG"
  width="100%" height="100%"
  defaultLeafIcon="{null}">
  >
    source="{dpHierarchy}"/>
  >
  >
    dataField="Region"/>
    dataField="Territory"/>
    dataField="Territory_Rep"
    headerText="Territory Rep"/>
    dataField="Revenues">
     dataField="Actual"/>
     dataField="Estimate"/>
   >
  >
 >
>

在ActionScript中创建分组

前面章节的示例我们使用的是MXML来创建分组，然而，您可能想让用户实时定义分组。以下示例通过事件处理器在ActionScript中创建分组：

"1.0" encoding="utf-8"?>
"" layout="vertical">
 
  [CDATA[
   import mx.collections.GroupingField;
   import mx.collections.Grouping;
   import mx.collections.GroupingCollection;
   import mx.collections.ArrayCollection;
   include "SimpleFlatData.as";
   [Bindable]
   public var myGColl:GroupingCollection = new GroupingCollection();
   private var myGrp:Grouping = new Grouping();
   private function initDG():void {
    // Initialize the GroupingCollection instance.
    myGColl.source = dpFlat;
    // The Grouping instance defines the grouping fields
    // in the collection, and the order of the groups
    // in the hierarchy.
    myGrp.fields =
     [new GroupingField("Region"), new GroupingField("Territory")];
    // The grouping property contains a Grouping instance.
    myGColl.grouping = myGrp;
    // Specify the GroupedCollection as the data provider for
    // the AdvancedDataGrid control.
    myADG.dataProvider=myGColl;
    // Refresh the display.
    myGColl.refresh();
   }
  ]]>
 
 "myADG"
  width="100%" height="100%"
  creationComplete="initDG();">
  
   "Region"/>
   "Territory"/>
   "Territory_Rep"
    headerText="Territory Rep"/>
   "Actual"/>
   "Estimate"/>