?今天有人问我flex中怎样向DataGrid添加背景图片，以及怎样使表格透明。
?? 其实这个查下文档就知道，可以如下用setStyle设置：
dataGrid.setStyle(
'
backgroundAlpha
'
,alpha)
??
??? 但是，没多久又告诉我，表头并不透明，看不到后面的背景图片，查了下api，简单继承下DataGrid，重写drawHeaderBackground方法就行，如：
override?
protected
?function?drawHeaderBackground(headerBG:UIComponent):
void
?
{
???//透明参数
???headerBG.alpha?=?_headerAlpha;
??//是否可见
???headerBG.visible?=?_headerVisible;
???
???super.drawHeaderBackground(headerBG);
?}
效果如下：
1，未处理的DataGrid，表格不透明
2,处理DataGrid后
测试效果可以点击：
http://www.munkiihouse.com/flexapps/StyleDataGrid/StyleDataGridDemo.html
代码：
1、继承于DataGrid：
package
?com.mh.components
{
?import?mx.controls.DataGrid;
?import?mx.core.UIComponent;
?public?class?StyleDataGrid?extends?DataGrid
?
{
??
??private?var?_headerBGAlpha:Number?=?1;??
??public?function?set?headerBGAlpha(value:Number):void
??
{
???_headerBGAlpha?=?value;
???invalidateDisplayList();
??}
??
??private?var?_headerBGVisible:Boolean?=?true;??
??public?function?set?headerBGVisible(value:Boolean):void
??
{
???_headerBGVisible?=?value;
???invalidateDisplayList();
??}
2、测试用例：
<?
xml?version="1.0"?encoding="utf-8"
?>
<
mx:Application?
xmlns:mx
="http://www.adobe.com/2006/mxml"
?layout
="absolute"
?xmlns:mhc
="com.mh.components.*"
?backgroundColor
="#FF8000"
?backgroundGradientColors
="[#ff8040,?#e14900]"
>
?
?
<
mx:Panel?
x
="10"
?y
="10"
?width
="550"
?height
="500"
?layout
="absolute"
?title
="Albums"
?paddingBottom
="10"
?paddingLeft
="10"
?paddingRight
="10"
?paddingTop
="10"
?backgroundImage
="@Embed('bg.jpg')"
>
??
<
mhc:StyleDataGrid?
id
="sdg_albums"
?dataProvider
="{Catalog.cataglog}"
?left
="10"
?right
="10"
?top
="10"
?bottom
="10"
>
??
???
<
mhc:columns
>
????
<
mx:DataGridColumn?
dataField
="ARTIST"
?headerText
="Artist"
?width
="200"
?
/>
????
<
mx:DataGridColumn?
dataField
="TITLE"
?headerText
="Title"
?
/>
????
<
mx:DataGridColumn?
dataField
="YEAR"
?headerText
="Year"
?width
="60"
?
/>
???
</
mhc:columns
>
??
??
</
mhc:StyleDataGrid
>
?
</
mx:Panel
>
?
?
?
<
mx:Panel?
x
="568"
?y
="10"
?width
="300"
?height
="200"
?layout
="vertical"
?title
="Controls"
?paddingTop
="10"
?paddingRight
="10"
?paddingBottom
="10"
?paddingLeft
="10"
>
??
<
mx:FormItem?
label
="Header?Alpha:"
??width
="100%"
?labelWidth
="120"
>
???
<
mx:HSlider?
id
="hs_h_alpha"
?value
="1"
?minimum
="0"
?maximum
="1"
?snapInterval
="0.1"
?allowTrackClick
="true"
?change
="{sdg_albums.headerBGAlpha?=?hs_h_alpha.value}"
?width
="100"
/>
???
??
</
mx:FormItem
>
??
??
<
mx:FormItem?
label
="Header?Visable:"
??labelWidth
="120"
>
???
<
mx:CheckBox?
id
="cb_visible"
?label
="Visable"
?selected
="true"
?change
="{sdg_albums.headerBGVisible?=?cb_visible.selected}"
/>
?????
??
</
mx:FormItem
>
??
<
mx:FormItem?
label
="Background?Alpha:"
??width
="100%"
?labelWidth
="120"
>
???
<
mx:HSlider?
id
="hs_bg_alpha"
?value
="0.5"
?minimum
="0"
?maximum
="1"
?snapInterval
="0.1"
?allowTrackClick
="true"
?change
="{sdg_albums.setStyle('backgroundAlpha',hs_bg_alpha.value)}"
?width
="100"
/>
???
??
</
mx:FormItem
>
?
</
mx:Panel
>
?
</
mx:Application
>
3、测试数据：
package
{
?public?class?Catalog
?{
??
??public?static?function?get?cataglog():XMLList
??{
???return?catalog..CD;
??}
??
??private?static?var?catalog:XML?=?
<
CATALOG
>
?????
<
CD
>
???????
<
TITLE
>
Empire?Burlesque
</
TITLE
>
???????
<
ARTIST
>
Bob?Dylan
</
ARTIST
>
???????
<
COUNTRY
>
USA
</
COUNTRY
>
???????
<
COMPANY
>
Columbia
</
COMPANY
>
???????
<
PRICE
>
10.90
</
PRICE
>
???????
<
YEAR
>
1985
</
YEAR
>
?????
</
CD
>
?????
<
CD
>
???????
<
TITLE
>
Hide?your?heart
</
TITLE
>
???????
<
ARTIST
>
Bonnie?Tylor
</
ARTIST
>
???????
<
COUNTRY
>
UK
</
COUNTRY
>
???????
<
COMPANY
>
CBS?Records
</
COMPANY
>
???????
<
PRICE
>
9.90
</
PRICE
>
???????
<
YEAR
>
1988
</
YEAR
>
?????
</
CD
>
?????
<
CD
>
???????
<
TITLE
>
Greatest?Hits
</
TITLE
>
???????
<
ARTIST
>
Dolly?Parton
</
ARTIST
>
???????
<
COUNTRY
>
USA
</
COUNTRY
>
???????
<
COMPANY
>
RCA
</
COMPANY
>
???????
<
PRICE
>
9.90
</
PRICE
>
???????
<
YEAR
>
1982
</
YEAR
>
?????
</
CD
>
?????
<
CD
>
???????
<
TITLE
>
Romanza
</
TITLE
>
???????
<
ARTIST
>
Andrea?Bocelli
</
ARTIST
>
???????
<
COUNTRY
>
EU
</
COUNTRY
>
???????
<
COMPANY
>
Polydor
</
COMPANY
>
???????
<
PRICE
>
10.80
</
PRICE
>
???????
<
YEAR
>
1996
</
YEAR
>
?????
</
CD
>
?????
<
CD
>
???????
<
TITLE
>
When?a?man?loves?a?woman
</
TITLE
>
???????
<
ARTIST
>
Percy?Sledge
</
ARTIST
>
???????
<
COUNTRY
>
USA
</
COUNTRY
>
???????
<
COMPANY
>
Atlantic
</
COMPANY
>
???????
<
PRICE
>
8.70
</
PRICE
>
???????
<
YEAR
>
1987
</
YEAR
>
?????
</
CD
>
?????
<
CD
>
???????
<
TITLE
>
Black?angel
</
TITLE
>
???????
<
ARTIST
>
Savage?Rose
</
ARTIST
>
???????
<
COUNTRY
>
EU
</
COUNTRY
>
???????
<
COMPANY
>
Mega
</
COMPANY
>
???????
<
PRICE
>
10.90
</
PRICE
>
???????
<
YEAR
>
1995
</
YEAR
>
?????
</
CD
>
?????
<
CD
>
???????
<
TITLE
>
1999?Grammy?Nominees
</
TITLE
>
???????
<
ARTIST
>
Many
</
ARTIST
>
???????
<
COUNTRY
>
USA
</
COUNTRY
>
???????
<
COMPANY
>
Grammy
</
COMPANY
>
???????
<
PRICE
>
10.20
</
PRICE
>
???????
<
YEAR
>
1999
</
YEAR
>
?????
</
CD
>
?????
<
CD
>
???????
<
TITLE
>
For?the?good?times
</
TITLE
>
???????
<
ARTIST
>
Kenny?Rogers
</
ARTIST
>
???????
<
COUNTRY
>
UK
</
COUNTRY
>
???????
<
COMPANY
>
Mucik?Master
</
COMPANY
>
???????
<
PRICE
>
8.70
</
PRICE
>
???????
<
YEAR
>
1995
</
YEAR
>
?????
</
CD
>
?????
<
CD
>
???????
<
TITLE
>
Big?Willie?style
</
TITLE
>
???????
<
ARTIST
>
Will?Smith
</
ARTIST
>
???????
<
COUNTRY
>
USA
</
COUNTRY
>
???????
<
COMPANY
>
Columbia
</
COMPANY
>
???????
<
PRICE
>
9.90
</
PRICE
>
???????
<
YEAR
>
1997
</
YEAR
>
?????
</
CD
>
?????
<
CD
>
???????
<
TITLE
>
Tupelo?Honey
</
TITLE
>
???????
<
ARTIST
>
Van?Morrison
</
ARTIST
>
???????
<
COUNTRY
>
UK
</
COUNTRY
>
???????
<
COMPANY
>
Polydor
</
COMPANY
>
???????
<
PRICE
>
8.20
</
PRICE
>
???????
<
YEAR
>
1971
</
YEAR
>
?????
</
CD
>
???
</
CATALOG
>
;
?}
}
?
?
http://www.blogjava.net/kissjava/archive/2009/04/30/262521.html
