Actionscript 3 在as3中卸载一个swf文件并加载另一个swf文件

当用户单击位于第一个加载的swf文件内的按钮（即嵌套在要卸载的欢迎swf文件内的按钮）时，我希望卸载先前加载的swf文件（welcome.swf）并加载另一个swf文件（topics.swf）.我已经尝试了所有的代码，但似乎都没有工作，我束手无策。请有人帮助。提前谢谢。下面是我的主文件中的代码和要卸载的外部swf

主文件

var box:Sprite = new Sprite;
box.x = 0;
box.y = 0;
addChild(box);
var loader = new Loader();
var swfURLReq:URLRequest = new URLRequest("welcome.swf");
loader.load(swfURLReq);
box.addChild(loader);

var loader = new Loader();`

button_1.addEventListener(MouseEvent.CLICK, button4);

function button4(event:MouseEvent) {
    loader.unloadAndStop();
    loader=null;
    var SWFRequest:URLRequest = new URLRequest("Topics.swf");
    loader.load(SWFRequest);
    loader.x = 0;
    loader.y = 0; 
    addChild(loader);

}

button_1.addEventListener(MouseEvent.CLICK, button4);

function button4(event:MouseEvent) {

    var target: Object = this;

    // Search the Main Loader from child swf.
    while (target.parent){
        target = target.parent;

        if (target is Loader){
            var loader:Loader = target as Loader;
            var SWFRequest:URLRequest = new URLRequest("Topics.swf");

            loader.load(SWFRequest);
            break;
        }       
    }
}

外部swf文件

var box:Sprite = new Sprite;
box.x = 0;
box.y = 0;
addChild(box);
var loader = new Loader();
var swfURLReq:URLRequest = new URLRequest("welcome.swf");
loader.load(swfURLReq);
box.addChild(loader);

var loader = new Loader();`

button_1.addEventListener(MouseEvent.CLICK, button4);

function button4(event:MouseEvent) {
    loader.unloadAndStop();
    loader=null;
    var SWFRequest:URLRequest = new URLRequest("Topics.swf");
    loader.load(SWFRequest);
    loader.x = 0;
    loader.y = 0; 
    addChild(loader);

}

button_1.addEventListener(MouseEvent.CLICK, button4);

function button4(event:MouseEvent) {

    var target: Object = this;

    // Search the Main Loader from child swf.
    while (target.parent){
        target = target.parent;

        if (target is Loader){
            var loader:Loader = target as Loader;
            var SWFRequest:URLRequest = new URLRequest("Topics.swf");

            loader.load(SWFRequest);
            break;
        }       
    }
}

---

我认为您应该在主加载程序中加载topics.swf。 因此，您应该从welcome.swf访问主加载程序

这代码不管用吗

外部swf文件

var box:Sprite = new Sprite;
box.x = 0;
box.y = 0;
addChild(box);
var loader = new Loader();
var swfURLReq:URLRequest = new URLRequest("welcome.swf");
loader.load(swfURLReq);
box.addChild(loader);

var loader = new Loader();`

button_1.addEventListener(MouseEvent.CLICK, button4);

function button4(event:MouseEvent) {
    loader.unloadAndStop();
    loader=null;
    var SWFRequest:URLRequest = new URLRequest("Topics.swf");
    loader.load(SWFRequest);
    loader.x = 0;
    loader.y = 0; 
    addChild(loader);

}

button_1.addEventListener(MouseEvent.CLICK, button4);

function button4(event:MouseEvent) {

    var target: Object = this;

    // Search the Main Loader from child swf.
    while (target.parent){
        target = target.parent;

        if (target is Loader){
            var loader:Loader = target as Loader;
            var SWFRequest:URLRequest = new URLRequest("Topics.swf");

            loader.load(SWFRequest);
            break;
        }       
    }
}

---

我可能会将所有加载/卸载责任转移到主文件中，内部swf只是通过

loaderInfo.sharedEvents

让主文件知道内部的一些事件，如下所示：

主文件：

var box:Sprite = new Sprite;
box.x = 0;
box.y = 0;
addChild(box);
var loader = new Loader();
var swfURLReq:URLRequest = new URLRequest("welcome.swf");
loader.load(swfURLReq);

function topicsRequestedHandler(event:Event):void {
    loader.contentLoaderInfo.sharedEvents.removeEventListener(
        "loadTopics", topicsRequestedHandler);
    loader.unloadAndStop();
    //load "Topics.swf" here
}   

loader.contentLoaderInfo.sharedEvents.addEventListener(
    "loadTopics", topicsRequestedHandler);

box.addChild(loader);

在外部文件中：

button_1.addEventListener(MouseEvent.CLICK, button4);

function button4(event:MouseEvent) {
    loaderInfo.sharedEvents.dispatchEvent(new Event("loadTopics"));
}

（未测试，但应能正常工作）

因此，对所有加载的文件使用此方案，您将在一个位置保持加载/卸载管理