as3：重新加載圖像

Question

我有一個圖像，我正試圖加載，然後重新加載。這是我對圖像的加載代碼：

public function loadImage(url:String, _w:int, _h:int):void 
    { 
     this._stwidth = _w; 
     this._stheight = _h; 
     this._imageURL = url; 

     if(!_imageURL) 
     { 
      return; 
     } 

     this.alpha = 1.0; //need this because we might have just faded the image out 

     _ldr.alpha = 0.0; 
     _prog.alpha = 1.0; 
     _sqr.alpha = 0.0; 
     _sqr.graphics.clear(); 

     if(_hasLoaded) 
     { 
      try 
      { 
       _ldr.close(); 
       _ldr.unload();     
      } 
      catch(e:Error) 
      { 
       //trace("bmdisplay has loaded once, but there was an error: " + e.message); 
      }   
     } 

     _ldr.contentLoaderInfo.addEventListener(ProgressEvent.PROGRESS, onProgress); 
     _ldr.contentLoaderInfo.addEventListener(Event.COMPLETE, onComplete); 
     _ldr.contentLoaderInfo.addEventListener(IOErrorEvent.IO_ERROR, onError); 
     _ldr.contentLoaderInfo.addEventListener(SecurityErrorEvent.SECURITY_ERROR, onError); 
     _ldr.contentLoaderInfo.addEventListener(Event.INIT, onOpen); 
     _ldr.load(new URLRequest(_imageURL)); 
    } 

出於某種原因，沒有第2次負載發出錯誤的代碼將不會加載圖像。 有人可以幫我解決這個問題嗎？

我完全失去了爲什麼我的變量_asLoaded會做我的錯。 我有一個onComplete（）處理程序，它將該var設置爲true，之後我從未將其設置爲false。

我不知道還有什麼我應該嘗試...

感謝

Answer 1

我將宣佈_ldr裏面的功能所以它的死每次啓動這個功能。我也不會使用這個unload()和close()方法。它更簡單，如果做這樣的事情（你需要有一個空的movieclip叫做「ldrHelper」）：

public function loadImage(url:String, _w:int, _h:int):void 
{ 
    // do your job and die bravely, no need to be global 
    var _ldr:Loader = new Loader(); 
    this._stwidth = _w; 
    this._stheight = _h; 
    this._imageURL = url; 

    if(!_imageURL) 
    { 
     return; 
    } 

    this.alpha = 1.0; //need this because we might have just faded the image out 

    // now you will need to make alpha = 1 on ldrHolder since _ldr is dead after this function 
    ldrHolder.alpha = 0.0; 
    _prog.alpha = 1.0; 
    _sqr.alpha = 0.0; 
    _sqr.graphics.clear(); 


    // remove the old image, doesn't matter whether its empty or not 
    while(ldrHolder.numChildren > 0){ 
     ldrHolder.removeChildAt(0); 
    } 

    //add image 
    ldrHolder.addChild(_ldr); 

    _ldr.contentLoaderInfo.addEventListener(ProgressEvent.PROGRESS, onProgress); 
    _ldr.contentLoaderInfo.addEventListener(Event.COMPLETE, onComplete); 
    _ldr.contentLoaderInfo.addEventListener(IOErrorEvent.IO_ERROR, onError); 
    _ldr.contentLoaderInfo.addEventListener(SecurityErrorEvent.SECURITY_ERROR, onError); 
    _ldr.contentLoaderInfo.addEventListener(Event.INIT, onOpen); 
    _ldr.load(new URLRequest(_imageURL)); 
} 

Answer 2

有時回我寫了一個輔助類來實現類似的東西。該輔助類擴展了Loader並提供圖像的自動縮放。以下是該類的代碼：

package {
 
    import flash.display.Loader; 
    import flash.geom.Rectangle; 
    import flash.net.URLRequest; 
    import flash.events.Event; 
    import flash.events.IOErrorEvent; 
    import flash.events.SecurityErrorEvent; 
    public class ImageLoader extends Loader { 
    private var _imageURL:String;   // URL of image 
    private var _imageBoundary:Rectangle; // boundary rectangle for the image 
    private var _loaded:Boolean;   // flag which tells whether image is loaded or not. 
    private var _isLoading:Boolean;   // flag which say if any loading is in progress 
    //Constructor function, which calls Loader's constructor 
    // and loads and resize the image 
    public function ImageLoader(url:String = null, rect:Rectangle = null):void { 
     super(); 
     _imageURL = url; 
     _imageBoundary = rect; 
     _loaded = false; 
     _isLoading = false; 
     loadImage(); 
    } 
    // sets the image for the loader and loads it 
    public function set imageURL(url:String):void { 
     _imageURL = url; 
     loadImage(); 
    } 
    // sets the boundary of the image and resizes it 
    public function set boundary(rect:Rectangle):void { 
     _imageBoundary = rect; 
     resizeImage(); 
    } 
    private function removeListeners():void { 
     this.contentLoaderInfo.removeEventListener(Event.COMPLETE, onComplete); 
     this.contentLoaderInfo.removeEventListener(IOErrorEvent.IO_ERROR, onError); 
     this.contentLoaderInfo.removeEventListener(SecurityErrorEvent.SECURITY_ERROR, onError); 
    } 
    private function onComplete(e:Event):void { 
     _loaded = true; 
     _isLoading = false; 
     removeListeners(); 
     resizeImage(); 
    } 
    //In case of error, we are not propogating the event 
    private function onError(e:Event):void { 
     e.stopImmediatePropagation(); 
     removeListeners(); 
    } 
    // real loading goes here 
    // it first closes and unloads the loader and 
    // then loads the image 
    private function loadImage():void { 
     if (_isLoading) { 
     trace("Some loading is in progess"); 
     return; 
     } 
     try { 
     this.close(); 
     this.unload(); 
     } 
     catch(e:Error) { 
     //discarded 
     } 
     if (!_imageURL) 
     return; 
     _loaded = false; 
     _isLoading = true; 
     this.contentLoaderInfo.addEventListener(Event.COMPLETE, onComplete); 
     this.contentLoaderInfo.addEventListener(IOErrorEvent.IO_ERROR, onError); 
     this.contentLoaderInfo.addEventListener(SecurityErrorEvent.SECURITY_ERROR, onError); 
     this.load(new URLRequest(_imageURL)); 
    } 
    // standard resizing function for image so that it's 
    // aspect ratio is maintained. 
    private function resizeImage():void { 
     if (!_imageBoundary || !_loaded) 
     return; 
     var aspect:Number = width/height; 
     var cAspect:Number = _imageBoundary.width/_imageBoundary.height; 
     if (aspect <= cAspect) { 
     this.height = _imageBoundary.height; 
     this.width = aspect * this.height; 
     } 
     else { 
     this.width = _imageBoundary.width; 
     this.height = this.width/aspect; 
     } 
     this.x = (_imageBoundary.width-this.width)/2 + _imageBoundary.x; 
     this.y = (_imageBoundary.height-this.height)/2 + _imageBoundary.y; 
    } 
    } 
}

您可以像這樣使用它：

var _imageLoader:ImageLoader = new ImageLoader(); 
_imageLoader.imageURL = " http://some-image-url "; 
_imageLoader.boundary = new Rectangle(0, 0, stage.stageWidth, stage.stageHeight); // or whatever suits you 

ImageLoader擴展了Loader類，以便您可以通過Loader類監聽所有的事件派發。希望能幫助到你。

Answer 3

嘗試實例新的Loader，可能是試圖回收它是給你的問題