ActionScript3。如何将嵌入MovieClip转换为MovieClip？

Question

我有HintMenu.swf库和MovieClips：

    public class PopupMenuItem extends MovieClip {

    [Embed(source="HintMenu.swf", symbol="ExternalMovie")]
    private var woodButtonClass:Class;

    public var activeItemSkin:MovieClip;

    public function PopupMenuItem(
        activeItemSkin = new woodButtonClass();
    )

但一开始，我收到以下错误：

[Fault] exception, information=TypeError: Error #1034: Type Coercion failed:
cannot convert energy.ui.alts.component.popup::PopupMenuItem_woodButtonClass@a7c0e19 to
flash.display.MovieClip.

稍后我需要使用它作为MovieClip。有什么解决办法吗？

Answer 1

实际上，您不能将嵌入MovieClip的1帧转换为MovieClip。优化原因: Flash将其转换为Sprite：

package {
    import flash.display.DisplayObjectContainer;
    import flash.display.MovieClip;
    import flash.display.Sprite;

    [SWF(backgroundColor="0x333333")]
    public class Test_MultipleSwfEmbed extends Sprite{
        [Embed(source="swf/HintMenu.swf", symbol="button1")]
        private var oneFrameMovieClip:Class;

        [Embed(source="swf/HintMenu.swf", symbol="button2")]
        private var twoFramesMovieClip:Class;

        public function Test_MultipleSwfEmbed() {

            //"is MovieClip" = true, when > 1 frame
            traceType(new oneFrameMovieClip()); // false, true, true
            traceType(new twoFramesMovieClip()); // true, true, true
        }

        private function traceType(mc:*):void {
            trace(mc is MovieClip, mc is Sprite, mc is DisplayObjectContainer);
        }
    }
}

Answer 2

使用as MovieClip。

activeItemSkin = new woodButtonClass() as MovieClip;

您需要确保woodButtonClass实际上是一个MovieClip。如果不是，那么activeItemSkin将为null。