我打了IDE和读取整天足够的学习，在AS3中，一个lib象征事项的出口类名。

I fought with the IDE and read around all day enough to learn that in AS3, the exported class name of a lib symbol matters.

我有hello.fla。在这里面我创建了一个简单的文本框带有字符串（'你好'） - coverted到一个符号（影片剪辑），并做了以下内容：

I have hello.fla. In it I created a simple textfield with a string ('hello') - coverted it to a symbol (movieclip) and did the following:

在我所做的一切，我核爆实例在舞台上。我想我可能会添加一些额外的功能，所以后来我居然还内置了Hello.as类，它扩展MovieClip和它生活在默认PKG *和整个FLA精细建立：

Once i did all that i nuked the instance on the stage. I thought I might add some extra functionality later so I actually also built a Hello.as class, which extends MovieClip, and which lives in the default pkg* and the whole fla builds fine:

package 
{
    import flash.display.MovieClip;

    public class Hello extends MovieClip
    {
        public function Hello()
        {
        }
    }
}

现在我main.fla，同一个文件夹，使用文档类主要和Main.as执行以下操作：

Now my main.fla, same folder, uses document class Main, and Main.as does the following:

private var h:MovieClip;
//...
h = new Hello();
this.addChild(h); //no joy

*的直到我得到这个工作，没有什么是在文件夹中：所有的文件都在根文件夹的

推荐答案

假设库元件住的.fla文件，如Hello.fla里面：

THE SOLUTION

Suppose that the library symbol lives inside an .fla such as Hello.fla:

package 
{
    import flash.display.MovieClip;
    import flash.text.TextField;

    /**
     * empty mc (blank stage) with a single library symbol containing whatever the hell you want (eg a shape). with settings:
     * class = Hello <=== this refers to a specific library symbol, not the entire Hello.fla and whatever else is on the stage when you build it.
     * export for AS : checked
     * export for runtime sharing (as Hello.swf) : checked <==== This was the step I'd missed
     * export in 1st frame : checked
     */
    public class Hello extends MovieClip
    {
        public function Hello()
        {
        }
    }
}

主时间轴/文档类：

The main timeline / document class :

package 
{
    import flash.display.Loader;
    import flash.display.MovieClip;
    import flash.net.URLRequest;
    import flash.events.Event;
    import Hello;

    /**
     * this is the document class.
     */
    public class Main extends MovieClip
    {
    	public function Main()
    	{
    		this.h = new Hello();
    		this.l= new Loader();
    		this.l.load( new URLRequest("Hello.swf") );
    		this.l.contentLoaderInfo.addEventListener(Event.COMPLETE, this.test);
    	}

    	public function test(e:Event)
    	{
    		this.h = new Hello();
    		h.x = 100;
    		h.y = 100;
    		this.addChild(this.h); //shows up on stage. Finally!
    	}

    	private var h:MovieClip;
    	private var l:Loader;
    }

}

希望它可以帮助一些其他的newbs像我这样的新AS3。

Hope it helps some other newbs like me new to AS3.