NSURLErrorDomain with code=-1100

问题:

I was trying to download a picture to my app from

The request failed with the error NSURLErrorDomain and the code is really -1100. The url should be correct since I checked it in the browser. Anyone knows why?

let userImageURL: String! = "http://i.imgur.com/QhCzQoR.jpg";
let url = NSURL(fileURLWithPath: userImageURL);
let request:NSURLRequest = NSURLRequest(URL: url!)
NSURLConnection.sendAsynchronousRequest(request, queue: NSOperationQueue.mainQueue(), completionHandler: { (response:NSURLResponse!, imageData:NSData!, error:NSError!) -> Void in
                let image = UIImage(data: imageData!);
 })

回答1:

The reason you are getting this problem is because you have used

let url = NSURL(fileURLWithPath: userImageURL);

Instead you should use:

let url = NSURL(string: userImageUrl)

回答2:

I code in Objective-C, it should be easy to convert it in Swift (small modification in fact, but the explanation is not that much related to code). If you check the error complete message, you'll get:

Error Domain=NSURLErrorDomain Code=-1100 "The requested URL was not found on this server." UserInfo=0x7997b7e0 {NSErrorFailingURLStringKey=file:///http:/i.imgur.com/QhCzQoR.jpg, NSErrorFailingURLKey=file:///http:/i.imgur.com/QhCzQoR.jpg, NSLocalizedDescription=The requested URL was not found on this server., NSUnderlyingError=0x799f3080 "The requested URL was not found on this server."}

Clearly, if you look carefully at the URL, you have file:///http:/i.imgur.com/QhCzQoR.jpg, which is not the URL wanted. If you log url.absoluteString, you'll see it to your URL, it's you that set it like this.

Why? Because you used fileURLWithPath: instead of URLWithString:. So change your line with:

let url = NSURL(URLWithString: userImageURL);

Some discussions about the differences between theses two: What is difference between URLWithString and fileURLWithPath of NSURL? or the doc.

Update: In Swift 4:

let url = URL(string: userImageURL)

We also recommend from Swift3+ to avoid NSStuff when there is Swift Equivalent: NSURL => URL.