我正在为 Blackberry Playbook 开发一个 ActionScript 3.0 应用程序。
我有十二个加载了 Loader 类的图像。我使用 Event.ENTER_FRAME 使用此事件处理程序淡入和淡出图像:
private function onEnterFrame(event:Event):void
{
imageToFront.alpha += 0.1; // slow fade
imageToBack.alpha -= 0.1;
if( imageToFront.alpha >= 1.0 )
{
imageToFront.alpha = 1.0;
// hide the first image
imageToBack.alpha = 0.0;
imageToBack.visible = false;
// remove the enter frame event listener
stage.removeEventListener( Event.ENTER_FRAME, onEnterFrame );
}
}
当用户单击图像时,会引发以下单击处理程序:
private function onImageClicked(event:MouseEvent):void
{
switch((event.currentTarget as Loader).name)
{
case imageCell11Back.name:
imageToFront = imageCell11Front;
imageToBack = imageCell11Back;
break;
case imageCell11Front.name:
imageToFront = imageCell11Back;
imageToBack = imageCell11Front;
break;
case imageCell12Back.name:
imageToFront = imageCell12Front;
imageToBack = imageCell12Back;
break;
case imageCell12Front.name:
imageToFront = imageCell12Back;
imageToBack = imageCell12Front;
break;
case imageCell13Back.name:
imageToFront = imageCell13Front;
imageToBack = imageCell13Back;
break;
case imageCell13Front.name:
imageToFront = imageCell13Back;
imageToBack = imageCell13Front;
break;
case imageCell21Back.name:
imageToFront = imageCell21Front;
imageToBack = imageCell21Back;
break;
case imageCell21Front.name:
imageToFront = imageCell21Back;
imageToBack = imageCell21Front;
break;
case imageCell22Back.name:
imageToFront = imageCell22Front;
imageToBack = imageCell22Back;
break;
case imageCell22Front.name:
imageToFront = imageCell22Back;
imageToBack = imageCell22Front;
break;
case imageCell23Back.name:
imageToFront = imageCell23Front;
imageToBack = imageCell23Back;
break;
case imageCell23Front.name:
imageToFront = imageCell23Back;
imageToBack = imageCell23Front;
break;
}
stage.addEventListener(Event.ENTER_FRAME, onEnterFrame);
imageToFront.visible = true;
}
我有以下问题:
如果用户在前一个图像尚未达到 alpha = 1.0 之前单击另一个图像,则该图像的 alpha 小于 1.0。
换句话说,我必须做一些事情来让onEnterFrame
函数设置 alpha 为 1.0。
有任何想法吗?
我试过了,stage.hasEventListener(Event.ENTER_FRAME)
但它不起作用。