Uiimage Temporaria

Question

I need to download an image, it is displayed, but after displaying it I need to delete it from the device. But always when I open the app again it is already loaded.

func getPhoto(pathPhoto: String, imageview: UIImageView) {

        activityIndicator = UIActivityIndicatorView(frame: CGRectMake(20, 20, imageview.frame.size.width - 40, imageview.frame.size.height - 40))
        activityIndicator.color = UIColor(red: 64.0/255.0, green: 109.0/255.0, blue: 157.0/255.0, alpha: 1.0)
        activityIndicator.startAnimating()
        imageview.addSubview(activityIndicator)

        var photoUrlString = urlImages

        photoUrlString += pathPhoto

        var imgURL: NSURL = NSURL(string: photoUrlString)!
        let request: NSURLRequest = NSURLRequest(URL: imgURL)
        NSURLConnection.sendAsynchronousRequest(request, queue: NSOperationQueue.mainQueue(), completionHandler: {(response: NSURLResponse!,data: NSData!,error: NSError!) -> Void in
            if error == nil {
                if data == nil {
                    NSLog("Erro ao baixar")
                } else {
                    self.image = UIImage(data: data)

                    dispatch_async(dispatch_get_main_queue(), {
                        self.activityIndicator.stopAnimating()
                        self.activityIndicator.removeFromSuperview()
                        imageview.image = self.image
                    })
                }
            }
        })
    }

Answer 1

The reason is that NSURLConnection automatically caches responses to HTTP requests locally. So while you can’t be saving the image in the app directory, iOS is saving it for me.

How you deal with it depends on why you are deleting the image on the device. If it’s because you want to serve a new image at a time, and you have control over the server, it might make sense to fix it there by setting the appropriate HTTP headers to inform clients not to cache the image.

To solve this problem I added the following code snippet after downloading the image:

NSURLCache().removeCachedResponseForRequest(request)

Staying like this:

func getPhoto(pathPhoto: String, imageview: UIImageView) {

        activityIndicator = UIActivityIndicatorView(frame: CGRectMake(20, 20, imageview.frame.size.width - 40, imageview.frame.size.height - 40))
        activityIndicator.color = UIColor(red: 64.0/255.0, green: 109.0/255.0, blue: 157.0/255.0, alpha: 1.0)
        activityIndicator.startAnimating()
        imageview.addSubview(activityIndicator)

        var photoUrlString = urlImages

        photoUrlString += pathPhoto

        var imgURL: NSURL = NSURL(string: photoUrlString)!
        let request: NSURLRequest = NSURLRequest(URL: imgURL)
        NSURLConnection.sendAsynchronousRequest(request, queue: NSOperationQueue.mainQueue(), completionHandler: {(response: NSURLResponse!,data: NSData!,error: NSError!) -> Void in
            if error == nil {
                if data == nil {
                    NSLog("Erro ao baixar")
                } else {
                    self.image = UIImage(data: data)

                    dispatch_async(dispatch_get_main_queue(), {
                        self.activityIndicator.stopAnimating()
                            self.activityIndicator.removeFromSuperview()
                            imageview.image = self.image

                            NSURLCache().removeCachedResponseForRequest(request)
                        })
                }
            }
        })
    }