flash不能再图片上画线条？

这是代码,出现的结果是画线只能在舞台中实现，不能再图片上显示：
package {
import flash.display.*;
import flash.events.MouseEvent;
public class test extends Sprite {
private var innerRect:Sprite = new Sprite();
//public var innerRect:Bitmap;
public function test() {
graphics.lineStyle(3, 0xFF0000, 1);
stage.addEventListener(MouseEvent.MOUSE_DOWN, mouseDownHandler);
stage.addEventListener(MouseEvent.MOUSE_UP, mouseUpHandler);
innerRect.graphics.lineStyle(1, 0x00FF00, 1);
innerRect.graphics.beginFill(0xFFFFFF);
innerRect.graphics.drawRect(10, 10, 200, 200);
innerRect.graphics.endFill();
innerRect.addEventListener(MouseEvent.MOUSE_DOWN, innerRectMouseDownHandler);
innerRect.addEventListener(MouseEvent.MOUSE_UP, innerRectMouseUpHandler);
addChild(innerRect);
addBitmap(innerRect);
}
public function addBitmap(innerRect:Sprite):void{
var bitmap:Bitmap;
var bitmapdata:BitmapData;
bitmap=new Bitmap;
bitmapdata=new BitmapData(300,300,true,0xffcccccc);
bitmap.bitmapData=bitmapdata;
bitmap.x=50;
bitmap.y=50;
innerRect.addChild(bitmap);
//addChild(bitmap);
}
private function mouseDownHandler(event:MouseEvent):void {
graphics.moveTo(event.stageX, event.stageY);
stage.addEventListener(MouseEvent.MOUSE_MOVE, mouseMoveHandler);
trace(event.toString());
}

private function mouseMoveHandler(event:MouseEvent):void {
graphics.lineTo(event.stageX, event.stageY);
}

private function mouseUpHandler(event:MouseEvent):void {
stage.removeEventListener(MouseEvent.MOUSE_MOVE, mouseMoveHandler);
}
private function innerRectMouseDownHandler(event:MouseEvent):void {
innerRect.graphics.moveTo(event.localX, event.localY);
innerRect.addEventListener(MouseEvent.MOUSE_MOVE, innerRectMouseMoveHandler);
}

private function innerRectMouseMoveHandler(event:MouseEvent):void {
innerRect.graphics.lineTo(event.localX, event.localY);
}

private function innerRectMouseUpHandler(event:MouseEvent):void {
innerRect.removeEventListener(MouseEvent.MOUSE_MOVE, innerRectMouseMoveHandler);
}
}
}

把图片分解成矢量图呢？

这些图片导入到flash后是以位图形式出现的，而我们平时画的都是矢量图。你不能对位图进行修改，除非你在“修改”菜单里选"位图"-"转换位图为矢量图"命令，这样就可以转换成为矢量图了，不过原来你画的那些线条都会按照填充色来处理。