flex图片裁剪

//构造函数  
public function testSprite()  
        {  
            this.loadImg();  
            this.createSmallCanvas();  
        }  
 
 
//装载图片  
public function loadImg(): void{  
            var loader: Loader = new Loader();  
            var url: String = "http://localhost/1.gif";  
            var urlRequest: URLRequest = new URLRequest(url);  
            loader.load(urlRequest);  
            this.addChild(loader);  
            loader.contentLoaderInfo.addEventListener(Event.COMPLETE, loadComplete);  
        }  
 
//图片装载成功后，创建一个sprite显示图片  
private function loadComplete(e: Event): void{  
            var loader: Loader = Loader(e.target.loader);  
            imgmap = loader.content as Bitmap;  
//下两行为图片缩放比例，但缩放后不能裁剪正确的图像位置  
//          imgmap.scaleX = .3;     
//          imgmap.scaleY = 0.35;  
            var imgCanvas: Sprite = new Sprite();  
            imgCanvas.x = 20;  
            imgCanvas.y = 20;  
            this.addChild(imgCanvas);  
            imgCanvas.graphics.lineStyle(1, 0x000000);  
            imgCanvas.graphics.beginFill(0xcccccc, 0.5);  
            imgCanvas.graphics.drawRoundRect(0,0,200,200,10,10);  
            imgCanvas.graphics.endFill();  
            imgCanvas.addChild(imgmap);  
//蒙版，超出此imgCanvas的区域不显示  
            imgmap.mask = this.imgMask();  
              
            this.createCut();  
        }  
 
private function imgMask(): Shape{  
            var mask: Shape = new Shape();  
            mask.x = 20;  
            mask.y = 20;  
            this.addChild(mask);  
            mask.graphics.beginFill(0xffffff,0.5);  
            mask.graphics.drawRect(0,0,200,200);  
            mask.graphics.endFill();  
            return mask;  
        }  
 
//创建要裁剪的框  
private function createCut(): void{  
            cutCanvas.x = 70;  
            cutCanvas.y = 70;  
            this.addChild(cutCanvas);  
            cutCanvas.graphics.lineStyle(1, 0xffffff);  
            cutCanvas.graphics.beginFill(0xffffff,0);  
            cutCanvas.graphics.drawRect(20,20,40,40);  
            cutCanvas.graphics.endFill();  
            cutCanvas.addEventListener(MouseEvent.MOUSE_DOWN, startDragHandler);  
            cutCanvas.addEventListener(MouseEvent.MOUSE_UP, endDragHandler);  
        }  
 
        private function startDragHandler(e: MouseEvent): void{  
            offsetx = e.stageX - cutCanvas.x;  
            offsety = e.stageY - cutCanvas.y;  
            cutCanvas.addEventListener(MouseEvent.MOUSE_MOVE, draggingHandler);  
        }  
          
        private function draggingHandler(e: MouseEvent): void{  
            cutCanvas.x = e.stageX - offsetx;  
            cutCanvas.y = e.stageY - offsety;  
            e.updateAfterEvent();  
        }  
          
        private function endDragHandler(e: MouseEvent): void{  
            this.showCutImg();  
            cutCanvas.removeEventListener(MouseEvent.MOUSE_MOVE, draggingHandler);  
        }  
 
//创建显示裁剪后的图片的Sprite  
        private function createSmallCanvas(): void{  
            smallImgCanvas.x = 280;  
            smallImgCanvas.y = 20;  
            this.addChild(smallImgCanvas);  
            smallImgCanvas.graphics.lineStyle(1,0xfffeee);  
            smallImgCanvas.graphics.beginFill(0x000000,0.5);  
            smallImgCanvas.graphics.drawRect(0,0,40,40);  
            smallImgCanvas.graphics.endFill();  
        }  
 
//裁剪图片  
private function showCutImg(): void{  
            var newdata: BitmapData = imgmap.bitmapData.clone();  
            var area: Rectangle = new Rectangle(cutCanvas.x-1, cutCanvas.y-1, cutCanvas.width, cutCanvas.height);  
            var nd: BitmapData = new BitmapData(cutCanvas.width, cutCanvas.height);  
nd.copyPixels(bd,new Rectangle(1,1,window.width-1,window.height-1),new Point(0,0));
     var newImg: Bitmap = new Bitmap(nd);  
            smallImgCanvas.addChild(newImg);  
        } 

转载http://kingapex.iteye.com/blog/299349修改