Flex Graphics实例演示：线条、渐变与填充

<?xml version="1.0" encoding="utf-8"?>
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009" 
      xmlns:s="library://ns.adobe.com/flex/spark" 
      xmlns:mx="library://ns.adobe.com/flex/halo"
      minWidth="1024" minHeight="768" xmlns:mx1="library://ns.adobe.com/flex/mx">
 
 <fx:Script>
  <![CDATA[
   import flash.geom.Matrix;
   
   /*
   画图形之前必要调用的函数（其中之一即可）：
   linestyle()、beginFill()、lineGradientStyle()、beginGradientFill()、beginBitmapFill()方法来设置线条样式和/或填充。 
   */
   
   //画矩形
   private function rect(rectX:Number, rectY:Number, rectWidth:Number, rectHeight:Number):void{
    rectBoxID.graphics.clear();
    if(radioLineID.selected){    //线性
     rectBoxID.graphics.lineStyle(20, 0xFF0000, 1.0, false, LineScaleMode.VERTICAL, CapsStyle.NONE, JointStyle.MITER, 100);
    }else if(radioGradientID.selected){    //渐变
     var matr:Matrix = new Matrix();
     matr.createGradientBox(20, 20, 0, 0, 0);
     //the last parameter can selete three type: SpreadMethod.PAD or SpreadMethod.REFLECT or SpreadMethod.REPEAT.
     rectBoxID.graphics.beginGradientFill(GradientType.LINEAR, [0xFF0000, 0x00FF00], [1, 1], [0x00, 0xFF], matr, SpreadMethod.REPEAT);
    }else if(radioFullID.selected){    //填充
     rectBoxID.graphics.beginFill(0xFF0000, 1.0);
    }
    rectBoxID.graphics.drawRect(rectX, rectY, rectWidth, rectHeight);
    //