AdvancedDataGrid的使用
相对DataGrid组件，AdvancedDataGrid主要有以下几个高级之处：
- 多列排序：按住Control键在点击某一列的表头来实现多列排序。
- 自定义行和列样式：通过设置行和列的styleFunction指向一个函数来样式化行列
- 显示分层数据：在组件的第一列显示一个可缩放的导航数来控制表格行的显示。
- 创建多列分组：将多列汇聚到同一列表头下。
- 使用单元渲染器（renderers）：跨越多栏使用同一渲染器或者一列使用多个渲染器。
多列排序
缺省的情况下，AdvancedDataGrid是按数据添加到它的DataProvider的顺序显示数据，和DataGrid组件一样，AdvancedDataGrid也允许您在数据显示后对数据进行排序。不同的是DataGrid只能基于单列排序，而AdvancedDataGrid支持基于多列的排序。
以下是多列排序的示例：
<?xml version="1.0"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml">
<mx:Script>
<![CDATA[
import mx.collections.ArrayCollection;
[Bindable]
private var dpADG:ArrayCollection = new ArrayCollection([
{Artist:'Pavement', Album:'Slanted and Enchanted', Price:12.99},
{Artist:'Pavement', Album:'Brighten the Corners', Price:13.99},
{Artist:'Saner', Album:'A Child Once', Price:14.99},
{Artist:'Saner', Album:'Helium Wings', Price:12.99},
{Artist:'The Doors', Album:'The Doors', Price:10.99},
{Artist:'The Doors', Album:'Morrison Hotel', Price:12.99},
{Artist:'Grateful Dead', Album:'American Beauty', Price:11.99},
{Artist:'Grateful Dead', Album:'In the Dark', Price:17.99},
{Artist:'Grateful Dead', Album:'Shakedown Street', Price:13.99},
{Artist:'The Doors', Album:'Strange Days', Price:12.99},
{Artist:'The Doors', Album:'The Best of the Doors', Price:10.99}
]);
]]>
</mx:Script>
<mx:AdvancedDataGrid width="100%" height="100%"
dataProvider="{dpADG}">
<mx:columns>
<mx:AdvancedDataGridColumn dataField="Artist" />
<mx:AdvancedDataGridColumn dataField="Album" />
<mx:AdvancedDataGridColumn dataField="Price" />
</mx:columns>
</mx:AdvancedDataGrid>
</mx:Application>
运行以上示例，如下进行排序：
- 点击AdvancedDataGrid组件的任意列表头对任意列进行排序，例如点击Artist列的列表头Artist列将升序进行排序，再次点击的话将按降序排序。
- 按住Control键，点击其他任意的列头，例如点击Price列头，将在保持Artist列降序排列的情况下，将Price列按升序排列。现在你可以从中发现某一艺术家最便宜的专辑。
- 再次点击Price列头，Price列将按降序排列
- 按住Control键，点击任意其他列，将其加入排序条件中。
自定义行列样式
通过使用AdvancedDataGrid组件的回调(callback)函数来自定义表格行列的样式，要控制某一行的样式，使用AdvancedDataGrid.styleFunction属性，要自定义某一列的样式，使用AdvancedDataGridColumn.styleFunction属性，AdvancedDataGrid.styleFunction指定的回调函数先执行，接着才执行AdvancedDataGridColumn.styleFunction属性指定的函数。
回调函数必须要有如下声明：
public function myStyleFunction(data:Object,column:SuperDataGridColumn):Object
该函数返回一个包含用于表示样式设置的styleName:value对的完整对象，或者null。styleName为样式属性的名称，如Color，而value为样式属性的值，如0x00FF00。
AdvancedDataGrid会在更新显示时调用回调函数，如应用启动时该组件第一次会绘制的时候，或者在您调用invalidateList()来刷新组件所有行的显示时。
本节的示例将使用回调函数来定义AdvancedDataGrid的样式，本节中所有的示例都使用以下StyleData.as文件中的数据：
[Bindable]
private var dpADG:ArrayCollection = new ArrayCollection([
{Artist:'Pavement', Album:'Slanted and Enchanted', Price:12.99},
{Artist:'Pavement', Album:'Brighten the Corners', Price:13.99},
{Artist:'Saner', Album:'A Child Once', Price:14.99},
{Artist:'Saner', Album:'Helium Wings', Price:12.99},
{Artist:'The Doors', Album:'The Doors', Price:10.99},
{Artist:'The Doors', Album:'Morrison Hotel', Price:12.99},
{Artist:'Grateful Dead', Album:'American Beauty', Price:11.99},
{Artist:'Grateful Dead', Album:'In the Dark', Price:17.99},
{Artist:'Grateful Dead', Album:'Shakedown Street', Price:13.99},
{Artist:'The Doors', Album:'Strange Days', Price:12.99},
{Artist:'The Doors', Album:'The Best of the Doors', Price:10.99}
]);
定义行样式
以下示例使用AdvancedDataGrid.styleFunction属性指定一个回调函数来定义表格行样式。在该示例中，您可以使用Button控件来选择AdvancedDataGrid.styleFunction中的artist，然后回调函数将会红色高亮显示所有被选择的行。
<?xml version="1.0"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml">
<mx:Script>
<![CDATA[
import mx.collections.ArrayCollection;
import mx.controls.advancedDataGridClasses.AdvancedDataGridColumn;
// Include the data for the AdvancedDataGrid control.
include "StyleData.as"
// Artist name to highlight.
protected var artistName:String;
// Event handler to set the selected artist's name
// based on the selected Button control.
public function setArtistName(event:Event):void
{
artistName=Button(event.currentTarget).label;
// Refresh row display.
myADG.invalidateList();
}
// Callback function that hightlights in red
// all rows for the selected artist.
public function myStyleFunc(data:Object,
col:AdvancedDataGridColumn):Object
{
if (data["Artist"] == artistName)
return {color:0xFF0000};
// Return null if the Artist name does not match.
return null;
}
]]>
</mx:Script>
<mx:AdvancedDataGrid id="myADG"
width="100%" height="100%"
dataProvider="{dpADG}"
styleFunction="myStyleFunc">
<mx:columns>
<mx:AdvancedDataGridColumn dataField="Artist"/>
<mx:AdvancedDataGridColumn dataField="Album"/>
<mx:AdvancedDataGridColumn dataField="Price"/>
</mx:columns>
</mx:AdvancedDataGrid>
<mx:HBox>
<mx:Button label="Pavement" click="setArtistName(event);"/>
<mx:Button label="Saner" click="setArtistName(event);"/>
<mx:Button label="The Doors" click="setArtistName(event);"/>
</mx:HBox>
</mx:Application>
定义列样式
以下示例修改上节的示例来定义AdvancedDataGrid的行和列样式。在该示例中，所有价格小于$11.00的单元都将显示为绿色。
<?xml version="1.0"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml">
<mx:Script>
<![CDATA[
import mx.collections.ArrayCollection;
import mx.controls.advancedDataGridClasses.AdvancedDataGridColumn;
// Include the data for the AdvancedDataGrid control.
include "StyleData.as"
// Artist name to highlight.
protected var artistName:String;
// Event handler to set the selected artist's name
// based on the selected Button control.
public function setArtistName(event:Event):void
{
artistName=Button(event.currentTarget).label;
// Refresh row display.
myADG.invalidateList();
}
// Callback function that hightlights in red
// all rows for the selected artist.
public function myStyleFunc(data:Object,
col:AdvancedDataGridColumn):Object
{
if (data["Artist"] == artistName)
return {color:0xFF0000};
// Return null if the Artist name does not match.
return null;
}
// Callback function that hightlights in green
// all entries in the Price column
// with a value less than $11.00.
public function myColStyleFunc(data:Object,
col:AdvancedDataGridColumn):Object
{
if(data["Price"] <= 11.00)
return {color:0x00FF00};
return null;
}
]]>
</mx:Script>
<mx:AdvancedDataGrid id="myADG"
width="100%" height="100%"
dataProvider="{dpADG}"
styleFunction="myStyleFunc">
<mx:columns>
<mx:AdvancedDataGridColumn dataField="Artist"/>
<mx:AdvancedDataGridColumn dataField="Album"/>
<mx:AdvancedDataGridColumn dataField="Price"
styleFunction="myColStyleFunc"/>
</mx:columns>
</mx:AdvancedDataGrid>
<mx:HBox>
<mx:Button label="Pavement" click="setArtistName(event);"/>
<mx:Button label="Saner" click="setArtistName(event);"/>
<mx:Button label="The Doors" click="setArtistName(event);"/>
</mx:HBox>
</mx:Application>
在列中使用数据格式器（formatter）
AdvancedDataGridColumn有一个formatter属性，通过它，您可以向列传递一个Formatter类，或者Formatter子类的实例。格式器类可以将数据转换为自定义的字符串。例如您可以使用CurrencyFormatter类在Price列值的加上美元符($)前缀。
格式器类可以和labelFunction属性或styleFunction属性设定的回调函数一起使用，如果您指定了一个回调函数，Flex在回调函数值返回后调用格式器类。
以下示例在修改自自定义行样式章节示例，在Price列增加了一个货币格式器以在价格前显示$前缀：
<?xml version="1.0"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml">
<mx:Script>
<![CDATA[
import mx.collections.ArrayCollection;
import mx.controls.advancedDataGridClasses.AdvancedDataGridColumn;
// Include the data for the AdvancedDataGrid control.
include "StyleData.as"
// Artist name to highlight.
protected var artistName:String;
// Event handler to set the selected artist's name
// based on the selected Button control.
public function setArtistName(event:Event):void
{
artistName=Button(event.currentTarget).label;
// Refresh row display.
myADG.invalidateList();
}
// Callback function that hightlights in red
// all rows for the selected artist.
public function myStyleFunc(data:Object,
col:AdvancedDataGridColumn):Object
{
if (data["Artist"] == artistName)
return {color:0xFF0000};
// Return null if the Artist name does not match.
return null;
}
]]>
</mx:Script>
<mx:AdvancedDataGrid id="myADG"
width="100%" height="100%"
dataProvider="{dpADG}"
styleFunction="myStyleFunc">
<mx:columns>
<mx:AdvancedDataGridColumn dataField="Artist"/>
<mx:AdvancedDataGridColumn dataField="Album"/>
<mx:AdvancedDataGridColumn width="75" dataField="Price">
<mx:formatter>
<mx:CurrencyFormatter/>
</mx:formatter>
</mx:AdvancedDataGridColumn>
</mx:columns>
</mx:AdvancedDataGrid>
<mx:HBox>
<mx:Button label="Pavement" click="setArtistName(event);"/>
<mx:Button label="Saner" click="setArtistName(event);"/>
<mx:Button label="The Doors" click="setArtistName(event);"/>
</mx:HBox>
</mx:Application>
