[ActionScript 3.0] 框选裁剪

package 
{
    import flash.display.Bitmap;
    import flash.display.BitmapData;
    import flash.display.Loader;
    import flash.display.Shape;
    import flash.display.Sprite;
    import flash.events.Event;
    import flash.events.MouseEvent;
    import flash.geom.Point;
    import flash.geom.Rectangle;
    import flash.net.URLRequest;
    import flash.utils.ByteArray;

    /**
      * ...
      * @author Frost.Yen
      */
    public class CutOut extends Sprite
    {
        private var ldr:Loader;
        private var cutContainer:Sprite;//存放裁剪的图片的容器
        private var primitiveContainer:Sprite;//存放原始图片的容器
        private var frame:Shape;//裁剪框
        private var downPoint:Point=new Point();
        private var bytearr:ByteArray=new ByteArray();


        public function CutOut():void
        {
            init();
        }

        private function init():void
        {
            this.graphics.beginFill(0xcccccc);
            this.graphics.drawRect(0, 0, stage.stageWidth, stage.stageHeight);
            this.graphics.endFill();

            cutContainer = new Sprite();
            primitiveContainer = new Sprite();
            frame = new Shape();

            cutContainer.x = 400;

            this.addChild(primitiveContainer);
            this.addChild(cutContainer);
            this.addChild(frame);

            ldr = new Loader();
            ldr.load(new URLRequest("http://hiphotos.baidu.com/frostyen/pic/item/7e49d8b53f6b48ffd9335aa2.jpg"));
            ldr.contentLoaderInfo.addEventListener(Event.COMPLETE, onComplete);
            primitiveContainer.addChild(ldr);
            this.addEventListener(MouseEvent.MOUSE_DOWN, onStageDown);
            stage.addEventListener(MouseEvent.MOUSE_UP, onStageUp);
        }
        private function onStageDown(e:MouseEvent):void
        {
            while (cutContainer.numChildren>0)
            {
                cutContainer.removeChildAt(0);
            }

            downPoint.x = mouseX;
            downPoint.y = mouseY;
            frame.graphics.clear();
            primitiveContainer.addEventListener(MouseEvent.MOUSE_MOVE,onMove);
        }

        private function onMove(e:MouseEvent):void
        {
            frame.graphics.clear();
            frame.graphics.lineStyle(1,0xff00ff);
            frame.graphics.drawRect(0, 0, mouseX - downPoint.x, mouseY - downPoint.y);
            frame.x = downPoint.x;
            frame.y = downPoint.y;
        }

        private function onStageUp(e:MouseEvent):void
        {
            primitiveContainer.removeEventListener(MouseEvent.MOUSE_MOVE,onMove);
            if (frame.width != 0)
            {
                var bmpd1:BitmapData = new BitmapData(primitiveContainer.width,primitiveContainer.height);
                bmpd1.draw(primitiveContainer);
                bytearr = bmpd1.getPixels(new Rectangle(frame.x,frame.y,frame.width,frame.height));
                bytearr.position = 0;
                var bmpd2:BitmapData = new BitmapData(frame.width,frame.height);
                try
                {
                    bmpd2.setPixels(new Rectangle(0,0,frame.width,frame.height),bytearr);
                }
                catch (err:Error)
                {
                    trace(err.message);//若裁剪框拉的范围超出原始图像范围会报此错，若解决，需深究.
                    frame.graphics.clear();
                    return;
                }
                var bmp:Bitmap = new Bitmap(bmpd2);
                cutContainer.addChild(bmp);
            }

        }

        private function onComplete(e:Event):void
        {
            ldr.scaleX = ldr.scaleY = 0.6;
        }

    }

}