Question

我有一个类（ImageLoader），它扩展Sprite容器并将外部图像加载到其实例。当我从另一个（Main）类实例化该类的对象时，我想让已加载图像的尺寸（宽度，高度）为此（Main）类所知。对于我来说似乎很难，因为在图像竞争加载后已知尺寸。但我不知道如何将这些信息从completeHandler事件处理程序传递给Main类。有什么想法吗？

package { import flash.display.Sprite; import flash.events.Event;



public class Main extends Sprite
{       
    private const img1:String = "pic1.jpg";
    private const img2:String = "pic2.jpg";

    private var myImg1:ImageLoader;
    private var myImg2:ImageLoader;

    public function Main():void
    {                                   
        myImg1 = new ImageLoader( img1 );
        myImg1.cacheAsBitmap = true;        

        myImg1.addEventListener(ImageLoader.COMPLETE, onImageLoadComplete);     

        addChild( myImg1 );         
    }               

    private function onImageLoadComplete(evt : Event) : void 
    {
        trace (ImageLoader(evt.currentTarget).getWidth());
        trace (ImageLoader(evt.currentTarget).getHeight());
    }

}

public class Main extends Sprite { private const img1:String = "pic1.jpg"; private const img2:String = "pic2.jpg"; private var myImg1:ImageLoader; private var myImg2:ImageLoader; public function Main():void { myImg1 = new ImageLoader( img1 ); myImg1.cacheAsBitmap = true; myImg1.addEventListener(ImageLoader.COMPLETE, onImageLoadComplete); addChild( myImg1 ); } private function onImageLoadComplete(evt : Event) : void { trace (ImageLoader(evt.currentTarget).getWidth()); trace (ImageLoader(evt.currentTarget).getHeight()); } }

}


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

public class ImageLoader extends Sprite
{
    private var loader:Loader;
    private var iWidth:int;
    private var iHeight:int;        

    public static const COMPLETE : String = "complete";

    public function ImageLoader( name:String ):void
    {               
        loader = new Loader();          
        loader.contentLoaderInfo.addEventListener( Event.COMPLETE, completeHandler );

        var request:URLRequest = new URLRequest( name );

        loader.load( request );
    }

    public function getWidth():int
    {
        return iWidth;
    }

    public function getHeight():int
    {
        return iHeight;
    }

    private function completeHandler( event:Event ):void
    {   
                    iWidth = event.target.content.width
        iHeight = event.target.content.height;

                    /* dispatcher MUST be after dimension computations */       
        dispatchEvent(new Event(ImageLoader.COMPLETE));

        this.addChild( loader.content );
    }       
}

Answer 1

您可以使用ImageLoader对象公共函数getWidth和getHeight来获取图像的宽度和高度，但是您需要知道加载何时完成，因此您可以从ImageLoader completeHandler调度事件，像：

// declare public static constant
public static const COMPLETE : String = "complete";
// inside complete handler
dispatchEvent(new Event(ImageLoader.COMPLETE));

完成此操作后，您现在可以从Main类中收听此事件：

myImg2 = new ImageLoader( img2 );
myImg2.addEventListener(ImageLoader.COMPLETE, onImageLoadComplete);

// inside onImageLoadComplete handler you can read the width and height:
private function loadComplete(evt : Event) : void 
{
    trace (ImageLoader(evt.currentTarget).getWidth());
    trace (ImageLoader(evt.currentTarget).getHeight());
}

是否可以将Loader对象的维度传递给另一个类？

1 个答案: