Flash 中位图九宫格的用法

最近发现flash里位图是无法使用scale9Grid这个属性,这是我整理的一个，原理很简单,用程序把位图切成九块,装里一个Sprite里,然后重写Sprite的width和height这两个方法,根据改变大小来重新设置位图的各个位置…这样就实现了位图的不变形缩放….

代码如下:

/**
* @project dynasty
* @author 糖糖 or 丁丁
* @copyright
* @document
* @history
* create 2009-2-20
* 位图Scale9Grid功能
**/
package
{
    import flash.display.Sprite;
    import flash.display.Bitmap;
    import flash.display.BitmapData;
    import flash.geom.Rectangle;
    import flash.geom.Point;
   
    public class BitmapScale9Grid extends Sprite
    {
        private var source : Bitmap;
        private var scaleGridTop : Number;
        private var scaleGridBottom : Number;
        private var scaleGridLeft : Number;
        private var scaleGridRight : Number;
       
        private var leftUp : Bitmap;
        private var leftCenter : Bitmap;
        private var leftBottom : Bitmap;
        private var centerUp : Bitmap;
        private var center : Bitmap;
        private var centerBottom : Bitmap;
        private var rightUp : Bitmap;
        private var rightCenter : Bitmap;
        private var rightBottom : Bitmap;
       
        private var _width : Number;
        private var _height : Number;
       
        private var minWidth : Number;
        private var minHeight : Number;
       
        public function BitmapScale9Grid(source:Bitmap, scaleGridTop:Number, scaleGridBottom:Number, scaleGridLeft:Number, scaleGridRight:Number )
        {
            this.source = source;
            this.scaleGridTop = scaleGridTop;
            this.scaleGridBottom = scaleGridBottom;
            this.scaleGridLeft = scaleGridLeft;
            this.scaleGridRight = scaleGridRight;
            init();
           
        }
       
        private function init() : void {
            _width = source.width;
            _height = source.height;
           
            leftUp = getBitmap(0, 0, scaleGridLeft, scaleGridTop);
            this.addChild(leftUp);
           
            leftCenter = getBitmap(0, scaleGridTop, scaleGridLeft, scaleGridBottom - scaleGridTop);
            this.addChild(leftCenter);
           
            leftBottom = getBitmap(0, scaleGridBottom, scaleGridLeft, source.height - scaleGridBottom);
            this.addChild(leftBottom);
           
            centerUp = getBitmap(scaleGridLeft, 0, scaleGridRight - scaleGridLeft, scaleGridTop);
            this.addChild(centerUp);
           
            center = getBitmap(scaleGridLeft, scaleGridTop, scaleGridRight - scaleGridLeft, scaleGridBottom - scaleGridTop);
            this.addChild(center);
           
            centerBottom = getBitmap(scaleGridLeft, scaleGridBottom, scaleGridRight - scaleGridLeft, source.height - scaleGridBottom);
            this.addChild(centerBottom);
           
            rightUp = getBitmap(scaleGridRight, 0, source.width - scaleGridRight, scaleGridTop);
            this.addChild(rightUp);
           
            rightCenter = getBitmap(scaleGridRight, scaleGridTop, source.width - scaleGridRight, scaleGridBottom - scaleGridTop);
            this.addChild(rightCenter);
           
            rightBottom = getBitmap(scaleGridRight, scaleGridBottom, source.width - scaleGridRight, source.height - scaleGridBottom);
            this.addChild(rightBottom);
           
            minWidth = leftUp.width + rightBottom.width;
            minHeight = leftBottom.height + rightBottom.height;
        }
       
        private function getBitmap(x:Number, y:Number, w:Number, h:Number) : Bitmap {
            var bit:BitmapData = new BitmapData(w, h);
            bit.copyPixels(source.bitmapData, new Rectangle(x, y, w, h), new Point(0, 0));
            var bitMap:Bitmap = new Bitmap(bit);
            bitMap.x = x;
            bitMap.y = y;
            return bitMap;
        }
       
        override public function set width(w : Number) : void {
            if(w < minWidth) {
                w = minWidth;
            }
            _width = w;
            refurbishSize();
        }
       
        override public function set height(h : Number) : void {
            if(h < minHeight) {
                h = minHeight;
            }
            _height = h;
            refurbishSize();
        }
       
        private function refurbishSize() : void {
            leftCenter.height = _height - leftUp.height - leftBottom.height;
            leftBottom.y = _height - leftBottom.height;
            centerUp.width = _width - leftUp.width - rightUp.width;
            center.width = centerUp.width;
            center.height = leftCenter.height;
            centerBottom.width = center.width;
            centerBottom.y = leftBottom.y;
            rightUp.x = _width - rightUp.width;
            rightCenter.x = rightUp.x;
            rightCenter.height = center.height;
            rightBottom.x = rightUp.x;
            rightBottom.y = leftBottom.y;
        }
    }
}