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最新推荐文章于 2023-12-04 17:03:24 发布

linking530

最新推荐文章于 2023-12-04 17:03:24 发布

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本文详细介绍了游戏开发中预加载机制的实现过程，包括如何使用预加载器类`Preloader`来高效地加载资源，并在游戏启动时展示加载进度条。通过事件监听和资源状态跟踪，确保资源在游戏开始前正确加载，提升用户体验。

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package
{
 import flash.display.DisplayObject;
 import flash.display.MovieClip;
 import flash.display.Sprite;
 import flash.display.StageAlign;
 import flash.display.StageScaleMode;
 import flash.events.Event;
 import flash.events.IOErrorEvent;
 import flash.events.ProgressEvent;
 import flash.utils.getDefinitionByName;
 
 
 public class Preloader extends MovieClip
 {
  private var bar:Sprite;
  
  public function Preloader()
  {
   if (stage)
   {
    stage.scaleMode = StageScaleMode.NO_SCALE;
    stage.align = StageAlign.TOP_LEFT;
   }
   addEventListener(Event.ENTER_FRAME, checkFrame);
   loaderInfo.addEventListener(ProgressEvent.PROGRESS, progress);
   loaderInfo.addEventListener(IOErrorEvent.IO_ERROR, ioError);
   
   // TODO show loader
   bar = new Sprite();
   bar.graphics.lineStyle(1, 0x4444ff, 1, true);
   bar.graphics.drawRect(0, 0, 100, 6);
   bar.x = stage.stageWidth / 2 - bar.width / 2;
   bar.y = stage.stageHeight / 2 - bar.height / 2;
   addChild(bar);
  }
  
  private function ioError(e:IOErrorEvent):void
  {
   trace(e.text);
  }
  
  private function progress(e:ProgressEvent):void
  {
   // TODO update loader
   bar.graphics.lineStyle(0, 0, 0);
   bar.graphics.beginFill(0x8888ff);
   bar.graphics.drawRect(1, 1, (e.bytesLoaded / e.bytesTotal) * 98, 4);
   bar.graphics.endFill();
   trace("loading:" + (e.bytesLoaded / e.bytesTotal) * 100);
   trace(e.bytesTotal);
  }
  
  private function checkFrame(e:Event):void
  {
   if (currentFrame == totalFrames)
   {
    stop();
    loadingFinished();
   }
  }
  
  private function loadingFinished():void
  {
   removeEventListener(Event.ENTER_FRAME, checkFrame);
   loaderInfo.removeEventListener(ProgressEvent.PROGRESS, progress);
   loaderInfo.removeEventListener(IOErrorEvent.IO_ERROR, ioError);
   
   // TODO hide loader
   removeChild(bar);
   bar = null;
   
   startup();
  }
  
  private function startup():void
  {
   var mainClass:Class = getDefinitionByName("Main") as Class;
   stage.addChild(new mainClass() as DisplayObject);

   parent.removeChild(this);
  }
 
 }

}

再来看看主程序怎么用的：
package
{            
    import flash.display.Sprite;            
    import flash.events.Event;            
                             
    [Frame(factoryClass="Preloader")]            
    public class Main extends Sprite            
    {            
        public function Main()            
        {            
            super();            
            this.addEventListener(Event.ADDED_TO_STAGE, onadded);            
        }            
                             
        protected function onadded(event:Event):void
        {            
            trace("真实内容加载到舞台");            
        }            
    }            
}