我正在尝试使用ActionScript的File.upload在Air SDK for iOS环境中上传文件，但File.upload无法正常工作。调用File.upload后，不会执行有关文件上载的处理程序，也不会捕获任何异常。当我检查服务器端的网络流量时，我发现执行File.upload后没有http请求甚至命中服务器。代码如下。
<?xml version="1.0" encoding="utf-8"?>
<s:View xmlns:fx="http://ns.adobe.com/mxml/2009"
xmlns:s="library://ns.adobe.com/flex/spark" title="HomeView">
<fx:Declarations>
<!-- Place non-visual elements (e.g., services, value objects) here -->
</fx:Declarations>
<fx:Script>
<![CDATA[
private var file:File;
private var dir:File;
//This method is executed to create a file and upload it when the Upload Button is pressed.
protected function OnUploadButtonPressed(event:MouseEvent):void{
trace("upload button clicked");
var urlReq:URLRequest = new URLRequest("http://10.60.99.31/MyPath/fileUploadTest.do");
urlReq.method = URLRequestMethod.POST;
var str:String = 'This is test';
var imageBytes:ByteArray = new ByteArray();
for ( var i:int = 0; i < str.length; i++ ) {
imageBytes.writeByte( str.charCodeAt(i) );
}
trace("size = " + imageBytes.length);
try{
dir = File.applicationStorageDirectory
//I also tested in several different directories
//dir = File.createTempDirectory();
//dir = File.documentsDirectory;
var now:Date = new Date();
var filename:String = "IMG" + now.fullYear + now.month + now.day + now.hours + now.minutes + now.seconds + now.milliseconds + ".txt";
file = dir.resolvePath( filename );
var stream:FileStream = new FileStream();
stream.open( file, FileMode.WRITE );
stream.writeBytes( imageBytes );
stream.close();
//Read back the file contents to check whether the file is written successfully.
var readStream:FileStream = new FileStream();
readStream.open(file, FileMode.READ);
var result:String = readStream.readUTFBytes(readStream.bytesAvailable);
trace("read back result = " + result);//The result is shown here as expected.
file.addEventListener( Event.COMPLETE, uploadComplete );
file.addEventListener( IOErrorEvent.IO_ERROR, ioError );
file.addEventListener( SecurityErrorEvent.SECURITY_ERROR, securityError );
file.addEventListener(ErrorEvent.ERROR, someError);
file.addEventListener(ProgressEvent.PROGRESS, onProgress);
file.upload( urlReq );//This line does not work. No handler is executed. No http request hit the server side.
trace("after file upload test");
}
catch( e:Error )
{
trace( e );
}
}
//Complete Handler
private function uploadComplete( event:Event ):void
{
trace( "Upload successful." );
}
//IOError handler
private function ioError( error:IOErrorEvent ):void
{
trace( "Upload failed: " + error.text );
}
//SecurityError handler
private function securityError(error:SecurityErrorEvent):void{
trace( "Security error:" + error.text );
}
//Other handler
private function someError(error:ErrorEvent):void{
trace("some error" + error.text);
}
//Progress handler
private function onProgress(event:ProgressEvent):void{
trace("progressHandler");
}
//This method is executed to invoke the URLLoader.load when the Tricky Button is pressed.
protected function OnTrickyButtonPressed(event:MouseEvent):void{
var urlReq:URLRequest = new URLRequest("http://200.60.99.31/");//This points to a non-existed server
urlReq.method = URLRequestMethod.POST;
urlReq.data = new ByteArray();
var loader:URLLoader = new URLLoader();
try{
loader.load(urlReq);//This line seems very important in iOS7. It decides whether the latter file.upload can work.
//But in iOS8, file.upload does not work even if this line is executed.
trace("after urlloader load");
}catch(e:Error){
trace(e);
}
}
]]>
</fx:Script>
<s:Button x="200" y="200" width="400" height="200" label="Upload" click="OnUploadButtonPressed(event)" />
<s:Button x="200" y="500" width="400" height="200" label="Tricky" click="OnTrickyButtonPressed(event)" />
</s:View>
在Air Simulator上执行时，按预期正常工作，文件已成功上传到服务器。 但是当在iOS设备（在我的情况下，iPad）上执行时，正如我早期解释的那样，没有关于文件上传的处理程序被执行，并且没有http请求事件到达服务器。所以我认为问题可能在客户端。
在我尝试解决问题的过程中，我在iOS7上发现了一些棘手的问题。也就是说，如果在调用File.upload方法之前调用URLLoader.load方法（即使URLLoader.load指向不存在的地址），File.upload将在iOS7上按预期工作。更具体地说，当方法 OnUploadButtonPressed 之前执行 OnTrickyButtonPressed 方法时，File.upload将在iOS7上成功。但这只发生在iOS7上。在iOS8上，File.upload总是拒绝工作，无论之前是否执行过URLLoader.load。
我认为在我的情况下问题不是下面两个链接中描述的沙盒问题或Firefox会话问题，因为甚至没有任何http请求到达服务器端。 似乎因为某些原因，iOS版Air SDK无法发送http请求。
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为了使我的问题更清楚，我在下面列出了我的环境：
最后，我想提一下，在我的情况下，使用URLLoader.load上传文件不是一个选项，因为我希望以后上传大文件，而这些文件无法使用URLLoader.load进行处理。
我已经为此奋斗了好几天。如果有人对此有任何想法，我真的很感激。 提前谢谢。
答案 0 :(得分：0)
最后我发现真正的问题不在于我提供的代码，而是关于http代理自动配置，而这个问题发生在iOS7和iOS8上。我在以下链接中详细描述了问题和解决方法。希望这会对你们中的一些人有所帮助。