Adobe AIR - Save image on hard drive

I found the below snippet to save an image to a specific folder with Adobe AIR.

How to modify it that the "Save As" OS-window comes up first? (So users can choose where to save the image on the hard-drive)

var arrBytes:ByteArray = PNGEncoder.encode(bmd);
    var file:File = File.desktopDirectory.resolvePath(folderName + "/" + fileName + fileNum + ".png");
    var fileStream:FileStream = new FileStream();
    //
    fileStream开发者_高级运维.open(file, FileMode.WRITE);
    fileStream.writeBytes(arrBytes);
    fileStream.close();

Thanks.

Use File.browseForSave:

import flash.filesystem.*;
import flash.events.Event;
import flash.utils.ByteArray;

var imgBytes:ByteArray = PNGEncoder.encode(bmd);
var docsDir:File = File.documentsDirectory;
try
{
    docsDir.browseForSave("Save As");
    docsDir.addEventListener(Event.SELECT, saveData);
}
catch (error:Error)
{
    trace("Failed:", error.message);
}

function saveData(event:Event):void 
{
    var newFile:File = event.target as File;
    if (!newFile.exists) // remove this 'if' if overwrite is OK.
    {
        var stream:FileStream = new FileStream();
        stream.open(newFile, FileMode.WRITE);
        stream.writeBytes(imgBytes);
        stream.close();
    } 
    else trace('Selected path already exists.');
}

The manual is always your friend :)

BTW, I see you're relatively new here - welcome to StackExchange! If you find my answer helpful, please be sure to select it as the answer.