Force to refresh movie clip? - actionscript-3

Question

I have a really simple code piece like that;
loadingMc.visible = true;
trace("ok");
// send photo to server
loadingMc.visible = false;
Sending photo takes 3-5 seconds but movie clip becomes visible only for last second of process. I can see "ok" message in output at start of the process. So i assume problem is not redrawing movie clip. Is there any option to force redraw before process starts?
UPDATE:
Sending to server part;
upload.addEventListener(MouseEvent.CLICK, function(evt:MouseEvent):void{
loadingText.visible = true;
trace("ok");
var bmd:BitmapData = new BitmapData(1024,768,true,0);
bmd.draw(imageArea);
savePicToServer(bmd);
});
function savePicToServer(bmd:BitmapData):void
{
var jpgEncoder:JPGEncoder = new JPGEncoder(85);
var jpgStream:ByteArray = jpgEncoder.encode(bmd);
var loader:URLLoader = new URLLoader();
configureListeners(loader);
var header:URLRequestHeader = new URLRequestHeader("Content-type", "application/octet-stream");
var request:URLRequest = new URLRequest("http://localhost/test/upload.php?key=prvkey");
request.requestHeaders.push(header);
request.method = URLRequestMethod.POST;
request.data = jpgStream;
loader.load(request);
}
In the COMPLETE event;
loadingText.visible = false;

Answer 1

EDIT
Just from reading your code, I don't see why this should not be working - but FP does strange things sometimes.
In similar cases, I used setTimeout() to force the player to delay the subsequent actions and allow the screen to refresh:
upload.addEventListener(MouseEvent.CLICK, function(evt:MouseEvent):void{
loadingText.visible = true;
trace("ok");
setTimeout( doSave, 10 );
});
private function doSave() : void {
var bmd:BitmapData = new BitmapData(1024,768,true,0);
bmd.draw(imageArea);
savePicToServer(bmd);
}
If this still doesn't work, perhaps a longer timeout will do the trick - but 10ms usually should be enough to refresh the screen.
EDIT
Another way would be to add and remove an ENTER_FRAME listener to make sure the frame really was refreshed:
upload.addEventListener(MouseEvent.CLICK, function(evt:MouseEvent):void{
loadingText.visible = true;
trace("ok");
addEventListener( Event.ENTER_FRAME, onNextFrame );
});
private function onNextFrame( ev:Event ) : void {
removeEventListener( Event.ENTER_FRAME, onNextFrame );
doSave();
}
private function doSave() : void {
var bmd:BitmapData = new BitmapData(1024,768,true,0);
bmd.draw(imageArea);
savePicToServer(bmd);
}