AS3.0 颜色渐变

package {
    import flash.display.*;
    import flash.display.Stage;
    import flash.display.Sprite;
    import flash.display.Graphics;
    import flash.display.GradientType;
    import flash.utils.Timer;
    import flash.events.TimerEvent;
    import flash.geom.*;
//==此项目是半成品
    public class ColorTest extends MovieClip {

        private var thisMc:MovieClip;
        private var stageMc:Stage;
        private var timer:Timer;
        private var sp:Sprite;
        private var colors:Array=[0x00FF00,0xFF0000];
        private var alphas:Array=[1,1];
        private var ratios:Array=[0,255];

        private var dif1:uint;
        private var dif2:uint;
        public function ColorTest(_stageMc:Stage,_thisMc:MovieClip) {
            thisMc=_thisMc;
            stageMc=_stageMc;
            init();
            timer=new Timer(25);
            timer.addEventListener(TimerEvent.TIMER,onTimer);
            //timer.start();

            dif1=0xFFFF00-0xFF0000;
            dif2=0x00FF00-0xFFFF00;
        }
        private function onTimer(e:TimerEvent) {

        }

        private function upDate() {
            sp=new Sprite();

        }

        private function changeSp(colors:Array,alphas:Array,ratios:Array,num:int) {
            sp=new Sprite();
            var matrix:Matrix=new Matrix();
            matrix.createGradientBox(10,200,Math.PI/2,0,0);
            //是弧度不是角度;
            sp.graphics.beginGradientFill(GradientType.LINEAR,colors,alphas,ratios,matrix);
            sp.graphics.drawRect(0, 0 ,10, 200);
            sp.graphics.endFill();
            sp.x=400;
            sp.y=300;
            thisMc.addChild(sp);
            while (thisMc.numChildren>2) {
                thisMc.removeChildAt(0);
            }
        }
        private function init() {
            var sp:Sprite=new Sprite();
            sp.rotation=180
            var colors:Array=[0x00FF00,0xFFFF00,0xFF0000];
            var alphas:Array=[1,1,1];
            var ratios:Array=[0,127,255];
            var matrix:Matrix=new Matrix();
            matrix.createGradientBox(10,200,Math.PI/2,0,0);
            //Math.PI/2是弧度不是角度;
            sp.graphics.beginGradientFill(GradientType.LINEAR,colors,alphas,ratios,matrix);
            sp.graphics.drawRect(0, 0 ,10, 150);
            sp.graphics.endFill();
            sp.x=400;
            sp.y=300;
            thisMc.addChild(sp);
        }

    }

}