[转] 加载SWF时一些有趣的测试

这几天做了一个关于加载和内存变化.以及被加载文件的清除的测试；

小有心得~不敢独享，摆到这里让各位大大拍砖；
代码如下:
public class LoadArrangeMain extends Sprite
        {
               
                public function LoadArrangeMain()
                {
                        init();
                }
                private function init():void {
               
                        trace("start Memory : " + System.totalMemory);
                       
                        loadStart();
                }
                private function loadStart():void {
                        var loader:Loader = new Loader();
                        var loadcontext:LoaderContext = new LoaderContext(false, ApplicationDomain.currentDomain);
                        loader.load(new URLRequest("loadSwf.swf"), loadcontext);
                        loader.contentLoaderInfo.addEventListener(Event.COMPLETE, completeHandle);

                }
                private function completeHandle(e:Event):void {
                        trace("loaded Memory : " + System.totalMemory)
                        trace(" IS HAS definetion atem? " +ApplicationDomain.currentDomain.hasDefinition("com.loadedSwf.Atem"));
                        e.currentTarget.removeEventListener(e.type, arguments.callee);
                        var loader:Loader = e.currentTarget.loader as Loader;
                        var loadSwf :*= loader.content;
                        stage.addEventListener(MouseEvent.CLICK, loadSwf.showMessage,false,0,true);
                        loadSwf = null;
                        loader.unloadAndStop(true);
                        loader = null;
                        //gc();
                        setTimeout(getDefinition, 3 * 1000);
                }

                private function getDefinition():void {
                        trace("unloaded Memory : " + System.totalMemory)
                        trace(" IS HAS definetion atem? " +ApplicationDomain.currentDomain.hasDefinition("com.loadedSwf.Atem"));
                                        }
                private function gc():void {
                        try {
                                var local_1:LocalConnection = new LocalConnection();
                                var local_2:LocalConnection = new LocalConnection();
                               
                                local_1.connect("foo");
                                local_2.connect("foo");
                        }catch (e:Error) {
                                trace("GC\n")
                        }
                       
                }
                        }
复制代码
输出结果为：
start Memory : 3006464
loaded Memory : 3866624
IS HAS definetion atem? true
unloaded Memory : 3690496
IS HAS definetion atem? true

加入SWF 后内存增加了 860000 B左右,通过unload 和GC之后 约小了 200000 左右；
那么剩下的是什么呢？
继续测试:
var arr:Array=[];
var loaders:Array=[];
for (var i:int=0;i<50;i++){
arr.push("loadSwf.swf");
}
load();

private function load(e:Event=null):void{
     if(arr==ull|| arr.length<1) complete();
var loader:loader=new Loader();
loader.load(new URLRequest(arr.shift()));
loader.contentLoadInfo.addEventLsiener(Event.COMPLETE,load);
loaders.push(loader);
}

private function complete():void{
trace ("loaded memory :"+System.totalMemory);
for each(var loader:Loader in loaders){
laoder.unloadAndStop(false);
loader=null;
}
loaders=null;
setTimerOut(showMemory,3*1000);
}

private function showMemory():void{
    trace("lasted  Memory:"+System.totalMemory);
}
复制代码
输出结果:
start memory 3035136
loaded memory 7426048
unload memory 4116480



通过后面的输出，我才知道~SWF被unload之后和我以为的清除存在着天壤之别；
它含有的类信息，已经被遍译好留在内存中了，而且如果此类绑到了库的素才，那占用的内存也会更大。

那么，第一个测试中我还给主SWF加了一个MouseEvnet.CLICK的弱引用，侦听器是 loadSwf实例中的公开方法；
常理，我们unload掉 该实例后 弱引用就会被清除了，可结果我测试出乎意料，一直都会响应！也就是 被加载的SWF 实例仍在内存中!
这个原因，深表遗憾，我实在是没有研究出来，我会在后面继续追加，如果有哪位大大知道具体原因，也希望你在跟贴中指点一二。

评论

1 楼 cloud21 2011-07-05  

自然是仍然存在引用了。