Using a slider to transition between 2 images - swift

Question

I am trying to learn the basics, but still very new to Xcode and Swift. I want to use a slider to transition between two images. When the slider is all the way to the left, image 1 should show in the image view. As the slider moves to the right, image 1 should fade and an image 2 should come into view. At the halfway point, both images should be visible (alpha = 0.5 for both image), superimposed one on top of the other. As the slider goes all the way to the right, image 1 should vanish and image 2 should be the only one visible.
Using UIImageView and a slider, I am able to adjust the alpha and "fade" my image based on the position of the slider.
import UIKit
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
#IBOutlet weak var UAimage: UIImageView!
#IBOutlet weak var Slider: UISlider!
#IBAction func sliderValueChange(_ sender: UISlider) {
var currentValue = Float(sender.value)
UAimage.alpha = CGFloat(sender.value)
}
}
At this point, I am looking for help getting the second image added and using alpha to programmatically control its opacity.

Answer 1

Just add a 2nd imageview over the first and add this line
imageview2.alpha = CGFloat(1 - sender.value)

Answer 2

import UIKit
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
#IBOutlet weak var UAimage: UIImageView!
/*
Your 2nd image.
On storyboard, go place a UIImageView directly on top of your initial imageView and set the image to whatever you'd like just as you did the original.
*/
#IBOutlet weak var UAimage2: UIImageView! //Your 2nd image
#IBOutlet weak var Slider: UISlider!
#IBAction func sliderValueChange(_ sender: UISlider) {
var currentValue = Float(sender.value)
UAimage.alpha = CGFloat(sender.value)
UAimag2.alpha = 1 - CGFloat(sender.value)
}
}