CODEWITHSUNDEEP
iosswiftanimationfadein
Luigi Festinante
Luigi Festinante

Reputation: 33

FadeIn animation not work swift 2

Below is my code. The fade out effect works fine. The fade in effect however is not animated . I can not solve this problem. Thanks to all those that will help me. Alpha is set 0 in storyboard

extension UIView {

    func fadeIn(duration: NSTimeInterval = 3.0, delay: NSTimeInterval = 0.0, completion: ((Bool) -> Void) = {(finished: Bool) -> Void in}) {
        UIView.animateWithDuration(duration, delay: delay, options: UIViewAnimationOptions.CurveLinear, animations: {
            self.alpha = 1.0
            }, completion: completion)  }

    func fadeOut(duration: NSTimeInterval = 2.0, delay: NSTimeInterval = 3.0, completion: (Bool) -> Void = {(finished: Bool) -> Void in}) {
        UIView.animateWithDuration(duration, delay: delay, options: UIViewAnimationOptions.CurveEaseOut, animations: {
            self.alpha = 0.0
            }, completion: completion)
    }

}

Upvotes: 2

Views: 651

Answers (2)

mtaweel
mtaweel

Reputation: 527

Calling UIView.animationWithDuration directly after it was called will cancel the previous animation even if you supply a delay in the function call. However, you can either use the completion function like @Daniel Hall suggested:

myView.fadeIn() {  _ in
   myView.fadeOut() 
}

Or if you do the fadeOut in a different method that is being triggered by some event exactly after fadeIn you can use dispatch_after to execute after delay time ( which should be the fadeIn duration in your case)

let delayTime = dispatch_time(DISPATCH_TIME_NOW, Int64(0.5 * Double(NSEC_PER_SEC)))
dispatch_after(delayTime, dispatch_get_main_queue()) {
    self.myView.fadeOut()
}

Upvotes: 2

Daniel Hall
Daniel Hall

Reputation: 13679

Your code works fine for me inside a playground:

import UIKit
import XCPlayground

extension UIView {
    func fadeIn(duration: NSTimeInterval = 3.0, delay: NSTimeInterval = 0.0, completion: ((Bool) -> Void) = {(finished: Bool) -> Void in}) {
        UIView.animateWithDuration(duration, delay: delay, options: UIViewAnimationOptions.CurveLinear, animations: {
            self.alpha = 1.0
        }, completion: completion)  
    }

    func fadeOut(duration: NSTimeInterval = 2.0, delay: NSTimeInterval = 3.0, completion: (Bool) -> Void = {(finished: Bool) -> Void in}) {
        UIView.animateWithDuration(duration, delay: delay, options: UIViewAnimationOptions.CurveEaseOut, animations: {
            self.alpha = 0.0
        }, completion: completion)
    }
}

let liveView = UIView(frame: CGRect(origin: CGPointZero, size: CGSize(width: 400, height: 400)))
XCPlaygroundPage.currentPage.liveView = liveView

let newView = UIView(frame: CGRect(x: 200, y: 200, width: 50, height: 50))
newView.backgroundColor = UIColor.greenColor()
newView.alpha = 0

liveView.addSubview(newView)
newView.fadeIn { _ in newView.fadeOut{ _ in newView.fadeIn() } }

It fades in, fades out on completion of the fade-in, then fades back in on completion of the fade-out.

Perhaps the issue it where / when you are calling the fadeIn() method on your view, and not a problem with your extension itself.

Upvotes: 1

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