Swipe slide and move imageView position - ios

Question

in my code some time it increases a lot and some time let the image position increase and decrease.
IBOutlet weak var bgImage: UIImageView!
IBOutlet weak var sliders: UISlider!
IBOutlet weak var imgViews: UIImageView!
var location = CGPoint(x: 0, y: 0)
var valueOFButterFly = 54.5
var lastValueOfSlider = Float()
#IBAction func sliderValue(_ sender: UISlider) {
print(sender.value)
if lastValueOfSlider >= sender.value {
valueOFButterFly = valueOFButterFly - 1
print("new value \(valueOFButterFly)")
imgViews.center = CGPoint(x: valueOFButterFly, y: 81.5)
}
else if (lastValueOfSlider < sender.value) {
valueOFButterFly = valueOFButterFly + 1
print("new value \(valueOFButterFly)")
imgViews.center = CGPoint(x: valueOFButterFly, y: 81.5)
}
else {
print("else if")
}
self.lastValueOfSlider = sender.value
}

Answer 1

In case you want to match the imageView's centre with that of the slider value, you need to set the slider's currentValue as imageView's centre instead of incrementing or decrementing by 1.
Also, update the imageView.center in valueOFButterFly's didSet property observer instead of updating it multiple times throughout the code.
class ViewController: UIViewController {
#IBOutlet weak var imageView: UIImageView!
#IBOutlet weak var slider: UISlider!
var lastValueOfSlider = Float()
var valueOFButterFly = 54.5 {
didSet {
imageView.center = CGPoint(x: self.valueOFButterFly, y: 81.5)
}
}
override func viewDidLoad() {
super.viewDidLoad()
slider.minimumValue = 0
slider.maximumValue = Float(UIScreen.main.bounds.width)
}
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
imageView.center = CGPoint(x: self.valueOFButterFly, y: 81.5)
}
#IBAction func sliderValue(_ sender: UISlider) {
print(sender.value)
valueOFButterFly = Double(sender.value)
self.lastValueOfSlider = sender.value
}
}
In the above code, I've used
slider.minimumValue = 0
slider.maximumValue = Float(UIScreen.main.bounds.width)
You can configure the above properties as per your requirement.