let url = NSURL(string: "http://chengkang.me/somepic.png")
if let data = NSData(contentsOfURL: url!) {
let image = UIImage(data: data)
}
//If you want to make the code run async, you can easily achieve this with GCD:
let url = NSURL(string: image.url)
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0)) {
let data = NSData(contentsOfURL: url!) //make sure your image in this url does exist, otherwise unwrap in a if let check
dispatch_async(dispatch_get_main_queue(), {
imageView.image = UIImage(data: data!)
});
}