ActionScript 3 + AIR + Android =如何下載PNG文件？在哪裏存儲？

Question

當使用Air + AS3 for Android時，如何從服務器下載png？

另外，我在哪裏存儲它，以便以後可以不用再下載就可以使用它？

問候 米爾扎

Answer 1

1. 更好地存儲您的ApplicationStoragePath文件中，這樣就可以避免一些安全（拒絕訪問）問題。

2. 確保writeBytesToFile（）需要指定使用的文件擴展名的文件路徑，以及（如「圖像/ first.png」）

   private function download(url:String):void 
   { 
       var urlRequest:URLRequest = new URLRequest(); 
       urlRequest.url = url; 
   
       var urlStream:URLStream = new URLStream(); 
       urlStream.addEventListener(Event.COMPLETE,onDownload_CompleteHandler); 
       urlStream.addEventListener(IOErrorEvent.IO_ERROR, onDownload_IOErrorHandler); 
       urlStream.addEventListener(HTTPStatusEvent.HTTP_RESPONSE_STATUS,onDownload_ResponseStatusHandler); 
       urlStream.addEventListener(SecurityErrorEvent.SECURITY_ERROR,onDownload_SecurityHandler); 
       urlStream.load(urlRequest); 
   } 
   
   protected function onDownload_CompleteHandler(event:Event):void 
   { 
       var urlStream:URLStream = event.currentTarget as URLStream; 
       var outBytes:ByteArray = new ByteArray;   
       urlStream.readBytes(outBytes,0,urlStream.bytesAvailable);   
       writeBytesToFile(outBytes); 
   } 
   
   
   private function writeBytesToFile(outBytes:ByteArray):void 
   { 
       var fileToWrite:File = File.applicationStorageDirectory.resolvePath("path/to/store/filenamewithextension");//Where you want store 
   
       var fileStream:FileStream = new FileStream(); 
       fileStream.addEventListener(Event.CLOSE, onFileStream_CloseHandler); 
       fileStream.addEventListener(IOErrorEvent.IO_ERROR,onFileStream_IOErrorHandler); 
       fileStream.openAsync(fileToWrite, FileMode.WRITE); 
       fileStream.writeBytes(outBytes, 0, outBytes.length); 
       fileStream.close(); 
   } 
   
   protected function onFileStream_CloseHandler(event:Event = null):void 
   { 
       trace("File successfully downloaded ");     
   } 
   
   protected function onFileStream_IOErrorHandler(event:IOErrorEvent):void 
   { 
       trace("File can't downloaded file doesn't exist "); 
   } 
   
   protected function onDownload_SecurityHandler(event:SecurityErrorEvent):void 
   { 
       logger.error("onDownload_SecurityHandler :: " + event.text);    
   } 
   
   protected function onDownload_ResponseStatusHandler(event:HTTPStatusEvent):void 
   { 
       trace("onDownload_ResponseStatusHandler :: " + event.status); 
   } 
   
   protected function onDownload_IOErrorHandler(event:IOErrorEvent):void 
   { 
       trace("onDownload_IOErrorHandler :: " + event.text);    
   }