I am trying to retrieve an image from a URL from a backendless database & convert this into an image, and return the function with a UIImageView. How do I handle a NSError in this code, and still return the UIImageView?
func getImage() -> UIView {
let imageLink = backendless.userService.currentUser.getProperty("Avatar")
let URL = NSURL(string: imageLink as! String)
let data = NSData(contentsOfURL: URL!)
let image: UIImage!
image = UIImage(data: data!)
return UIImageView(image: image!)
}
Updated my answer based on the comments.
You can return a placeholder image if the one you are looking for is not available:
So your method will look like the following:
func getImage() -> UIImage {
var imageLink = backendless.userService.currentUser.getProperty("Avatar")
guard let imageUrl = imageLink as? String,
let URL = NSURL(string: imageUrl),
let data = NSData(contentsOfURL: URL)
else {
return UIImage(named: "placeholder")
}
return UIImage(data: data)
}
Here is how you use it:
func koloda(koloda: KolodaView, viewForCardAtIndex index: UInt) -> UIView {
return UIImageView(image: getImage())
}
You can download image from an URL and return as an UIImage with this code. Hope this helps:
func downloadImage(url: NSURL) -> UIImage {
getDataFromUrl(url) { (data, response, error) in
dispatch_async(dispatch_get_main_queue()) { () -> Void in
guard let data = data where error == nil else { return }
let image:UIImage = UIImage(data: data)!
return image
}
}
}
Update: this is the getDataFromUrl function
func getDataFromUrl(url:NSURL, completion: ((data: NSData?, response: NSURLResponse?, error: NSError? ) -> Void)) {
NSURLSession.sharedSession().dataTaskWithURL(url) { (data, response, error) in
completion(data: data, response: response, error: error)
}.resume()
}
来源:https://stackoverflow.com/questions/38556524/how-to-handle-nsdata-and-return-uiimage-swift