AS3放大镜工具类

package {
import flash.display.Bitmap;
import flash.display.BitmapData;
import flash.display.DisplayObject;
import flash.display.DisplayObjectContainer;
import flash.display.Sprite;
import flash.geom.Point;
import flash.geom.Rectangle;
import flash.ui.Mouse;
import flash.events.Event;
import flash.events.MouseEvent;
import flash.filters.DropShadowFilter;

public class MagGlass extends Sprite {
private const MAXSIZE :uint = 2880;
private var _zoom :Number;
private var _zoomSmall :Number;
private var _imageW :Number;
private var _imageH :Number;
private var _imageBitmap :Bitmap;
private var _newBitmap :Bitmap;
private var _imageBitmapData:BitmapData;
private var _dataW :Number;
private var _dataH :Number;
private var _filtered :Boolean;
private var _glassSp :Sprite;
private var _isZooming :Boolean;
private var _Stage :Object;
private var _target :DisplayObject;
/*
* Param1 需要缩放的对象
* Param2 缩放的倍数,默认为3倍
* Param3 显示框的宽度
* Param4 显示框的高度
* Param5 是否添加阴影滤镜
*/
public function MagGlass($target:DisplayObject, $zoom:Number = 3, $width:Number = 100, $height:Number = 80, $filtered:Boolean = true) {
trace("MagGlass v01");
if ($target is Bitmap) {
_imageBitmap = $target as Bitmap;
}else {
_imageBitmap = getBitmap($target);
}
_imageBitmap.scaleX = $zoom;
_imageBitmap.scaleY = $zoom;
if (_imageBitmap.width > MAXSIZE || _imageBitmap.width > MAXSIZE) {
trace("图片尺寸超过范围！");
return;
}
var newSp:Sprite = new Sprite();
newSp.addChild(_imageBitmap);
_newBitmap = getBitmap(newSp);
_imageBitmapData = _newBitmap.bitmapData;
_target = $target;
_zoom = $zoom;
_imageW = $width;
_imageH = $height;
_filtered = $filtered;
this.addEventListener(Event.ADDED_TO_STAGE, addToStage);
}

private function addToStage(event:Event):void {
this.removeEventListener(Event.ADDED_TO_STAGE, addToStage);
_Stage = stage;
initGlass();
initEvent(_target);
}

private function initGlass():void {
_glassSp = new Sprite();
_glassSp.buttonMode = _glassSp.mouseChildren = _glassSp.mouseEnabled = false;
if(_filtered) _glassSp.filters = [new DropShadowFilter()];
addChild(_glassSp);
}

private function initEvent($target:DisplayObject):void {
$target.addEventListener(MouseEvent.ROLL_OUT, targetOut,true);
$target.addEventListener(MouseEvent.MOUSE_DOWN, targetDown);
_Stage.addEventListener(MouseEvent.MOUSE_UP, targetOut);
}

private function targetDown(event:MouseEvent):void {
_isZooming = true;
Mouse.hide();
var hitPoint:Point = new Point(event.localX, event.localY);
//trace("hitPoint",hitPoint);
_glassSp.x = this.mouseX- _imageW / 2;
_glassSp.y = this.mouseY- _imageH / 2;
ShowBig(hitPoint);

this.addEventListener(MouseEvent.MOUSE_MOVE,targetMove);
}

private function glassClear():void {
_glassSp.graphics.clear();
}
private function targetOut(event:MouseEvent):void {
_isZooming = false;
glassClear();
Mouse.show();
this.removeEventListener(MouseEvent.MOUSE_MOVE,targetMove);
}

private function targetMove(event:MouseEvent):void {
var movePoint:Point = new Point(_target.mouseX, _target.mouseY);
//trace("movePoint",movePoint);
_glassSp.x = this.mouseX- _imageW / 2;
_glassSp.y = this.mouseY- _imageH / 2;
ShowBig(movePoint);
event.updateAfterEvent();
}

private function getBitmap($target:DisplayObject):Bitmap {
var bitmapData:BitmapData = new BitmapData($target.width, $target.height,true,0xffff0000);
bitmapData.draw($target);
return new Bitmap(bitmapData);
}

/*
* Param1 坐标,即需要显示的坐标中点
*/
private function ShowBig($point:Point) {
drawGlass(new Point($point.x*_zoom,$point.y*_zoom));
}

private function drawGlass($point:Point):void {
var curBitmapData:BitmapData;
var curBitmap :Bitmap;
var startX :Number = $point.x - _imageW / 2;
var startY :Number = $point.y - _imageH / 2;
curBitmap = new Bitmap(new BitmapData(_imageW, _imageH));
curBitmap.bitmapData.copyPixels(_imageBitmapData, new Rectangle(startX, startY, _imageW, _imageH), new Point(0, 0));
curBitmapData = curBitmap.bitmapData;
_glassSp.graphics.clear();
_glassSp.graphics.lineStyle();
_glassSp.graphics.beginBitmapFill(curBitmapData);
_glassSp.graphics.drawRect(0, 0, _imageW, _imageH);
_glassSp.graphics.endFill();
}
}
}

使用方法：
var mMagGlass:MagGlass = new MagGlass(mc,3,150,150,true);
addChild(mMagGlass);

　　AS3放大镜工具类