flex除了application支持背景渐变色外，其它控制都不支持，近日需要这个功能，在网上搜到些资料整理如下：

 

类文件

GradientBorder.as

 /**
  * 背景渐变色
  * whisht
  * */
 package {

     import flash.display.*;
     import flash.geom.*;
     import flash.utils.*;

     import mx.core.EdgeMetrics;
     import mx.skins.halo.HaloBorder;
     import mx.utils.ColorUtil;
     import mx.utils.GraphicsUtil;

     public class GradientBorder extends HaloBorder
     {

         private var topCornerRadius:Number;        // top corner radius
         private var bottomCornerRadius:Number;    // bottom corner radius
         private var fillColors:Array;            // fill colors (two)
         private var setup:Boolean;


         private function setupStyles():void
         {
             fillColors = getStyle("fillColors") as Array;
             if (!fillColors) fillColors = [0xFFFFFF, 0xFFFFFF];

             topCornerRadius = getStyle("cornerRadius") as Number;
             if (!topCornerRadius) topCornerRadius = 0;

             bottomCornerRadius = getStyle("bottomCornerRadius") as Number;
             if (!bottomCornerRadius) bottomCornerRadius = topCornerRadius;

         }


         override protected function updateDisplayList(unscaledWidth:Number, unscaledHeight:Number):void
         {
             super.updateDisplayList(unscaledWidth, unscaledHeight);

             setupStyles();

             var g:Graphics = graphics;
             var b:EdgeMetrics = borderMetrics;
             var w:Number = unscaledWidth - b.left - b.right;
             var h:Number = unscaledHeight - b.top - b.bottom;
             var m:Matrix = verticalGradientMatrix(0, 0, w, h);

             g.beginGradientFill("linear", fillColors, [1, 1], [0, 255], m);

             var tr:Number = Math.max(topCornerRadius-2, 0);
             var br:Number = Math.max(bottomCornerRadius-2, 0);

             GraphicsUtil.drawRoundRectComplex(g, b.left, b.top, w, h, tr, tr, br, br);
             g.endFill();

         }

     }
 }

 

 

调用示例

 <?xml version="1.0" encoding="utf-8"?>
 <mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
     layout="vertical" backgroundImage="" backgroundColor="white">

     <mx:Style>

         .gradient
         {
             border-style: solid;
             border-thickness: 0;
             border-skin: ClassReference("GradientBorder");
             fill-colors: #0099FF, #000099;
             corner-radius: 10;
             drop-shadow-enabled: true;
         }

     </mx:Style>

     <mx:Script>
         <![CDATA[
             private function changeStyle():void
             {
                 box.setStyle("fillColors", [col1.value, col2.value]);
                 box.setStyle("cornerRadius", corner.value);
             }
         ]]>
     </mx:Script>

     <mx:VBox id="box" styleName="gradient" width="400" height="300" verticalAlign="middle" horizontalAlign="center">
         <mx:FormItem label="Color 1:">
             <mx:ColorPicker id="col1" change="changeStyle()" selectedColor="0x0099FF"/>
         </mx:FormItem>
         <mx:FormItem label="Color 2:">
             <mx:ColorPicker id="col2" change="changeStyle()" selectedColor="0x000099"/>
         </mx:FormItem>
         <mx:FormItem label="Corner radius:">
             <mx:HSlider id="corner" value="10" minimum="0" maximum="100" change="changeStyle()"/>
         </mx:FormItem>
     </mx:VBox>

 </mx:Application>