import mx.controls.Alert;
import mx.events.FlexEvent;

private var urlStream:URLStream;
private var fData:ByteArray;

private var bytesLoaded:Number = 0;
private var totalBytesLoaded:Number = 0;
private var bytesTotal:Number = 0;

private var fileName:String = ”;
private var file:File;

private var fileStream:FileStream = new FileStream;

protected function init(event:FlexEvent):void
{
urlStream = new URLStream;
urlStream.addEventListener(ProgressEvent.PROGRESS, onProgress);
urlStream.addEventListener(Event.COMPLETE, onComplete);
fileInput.text = “http://10.10.10.21/mov/cats.avi”;
}

private function startDownload():void
{
bytesLoaded = 0;
bytesTotal = 0;
totalBytesLoaded = 0;

var url:String = fileInput.text;
var index:int = url.lastIndexOf(’/');
fileName = url.substring(index+1, url.length);
file = File.desktopDirectory.resolvePath(fileName);
status = file.url;

if(file.exists)
{
btn.label = ‘Download’;
mx.controls.Alert.show(’Please remove “‘+fileName+’” from your disk’, ‘File with the same name already exists’);
return;
}
output.text += ‘Downloading…\n’;

urlStream.load( new URLRequest(url) );
fData = new ByteArray;
fileInput.enabled = false;

fileStream.open(file, file.exists ? FileMode.APPEND:FileMode.WRITE);
}

private function pauseDownload():void
{
output.text += ‘Downloading is paused\n’;
if(urlStream.connected)
{
fData.clear();
urlStream.readBytes(fData, fData.length);
urlStream.close();
fileStream.writeBytes(fData);
}

fileStream.close();

totalBytesLoaded += bytesLoaded;
trace( “pause size:”+ totalBytesLoaded);

}

private function resumeDownload():void
{
output.text += ‘Downloading… \n’;
output.text +=’bytes=’+totalBytesLoaded+’-'+bytesTotal + ‘\n’;
var header0:URLRequestHeader = new URLRequestHeader(’range’, ‘bytes=’+totalBytesLoaded+’-'+bytesTotal);
var request:URLRequest = new URLRequest(fileInput.text);
request.requestHeaders.push(header0);

urlStream.load( request );

fileStream.open(file, file.exists ? FileMode.APPEND:FileMode.WRITE);

}

private function onProgress(event:ProgressEvent):void
{
bytesLoaded = event.bytesLoaded;
if(bytesTotal == 0)
bytesTotal = event.bytesTotal;

trace( “size:”+ bytesLoaded);

progressBar.setProgress( (totalBytesLoaded + event.bytesLoaded) / bytesTotal, progressBar.maximum);

if(urlStream.bytesAvailable == 0) return;
if(urlStream.connected)
{
fData.clear();
urlStream.readBytes(fData, fData.length);
fileStream.writeBytes(fData);

}
}

private function onComplete(event:Event):void
{
output.text += ‘Download complete\n’;
bytesLoaded = 0;
bytesTotal = 0;
totalBytesLoaded = 0;
progressBar.setProgress(0, 1);

if(urlStream.connected)
{
fData.clear();
urlStream.readBytes(fData, fData.length);
urlStream.close();
fileStream.writeBytes(fData);
}

fileInput.enabled = true;
btn.label = ‘Download’;
fData = null;

fileStream.close();

System.gc();
}

private function writeFile():void
{
output.text += ‘Saving File…\n’;
var fileStream:FileStream = new FileStream;
fileStream.open(file, file.exists ? FileMode.APPEND:FileMode.WRITE);
fileStream.writeBytes(fData);
fileStream.close();
output.text += ‘File Saved\n’;
}

private function btnClickHandler():void
{
if(bytesLoaded == 0)
{
btn.label = ‘Pause’;
startDownload();
}
else
{
if(urlStream.connected)
{
btn.label = ‘Resume’;
pauseDownload();
}
else
{
btn.label = ‘Pause’;
resumeDownload();
}
}
}

—————————————————————————

if(bytesTotal != event.bytesTotal)
bytesTotal = event.bytesTotal;

progressBar.setProgress( (totalBytesLoaded + event.bytesLoaded) / event.bytesTotal, progressBar.maximum);

————–

with this:

————–
if(bytesTotal == 0)
bytesTotal = event.bytesTotal;

progressBar.setProgress( (totalBytesLoaded + event.bytesLoaded) / bytesTotal, progressBar.maximum);

Thank you again to share your code.