Blinking effect on UILabel

Question

I have a UILabel with background color as grey.

I want a blinking effect on this label like it should become a little white & then become gray and it should keep happen till I turn it off programatically.

Any clue how to achieve this?

Answer 1

Here is my solution in Swift 4.0 with extension for any UIVIew

extension UIView{
    func blink() {
        self.alpha = 0.2

        UIView.animate(withDuration: 1,
                                   delay: 0.0,
                                   options: [.curveLinear,
                                             .repeat,
                                             .autoreverse],
                                   animations: { self.alpha = 1.0 },
                                   completion: nil)   
    }
}

Answer 2

Tweaking Krishnabhadra Answer to give a better blink effect

Declare a Class variable bool blinkStatus;

And paste code given below

NSTimer *yourtimer = [NSTimer scheduledTimerWithTimeInterval:(NSTimeInterval)(10.0 / 60.0)  target:self selector:@selector(blink) userInfo:nil repeats:TRUE];
    blinkStatus = FALSE;

-(void)blink{
    if(blinkStatus == FALSE){
        yourLabel.hidden=NO;
        blinkStatus = TRUE;
    }else {
        yourLabel.hidden=YES;
        blinkStatus = FALSE;
    }
}

Answer 3

    int count;
    NSTimer *timer;

      timer= [NSTimer
                  scheduledTimerWithTimeInterval:(NSTimeInterval)(0.5)
                  target:self
                  selector:@selector(animationStart)
                  userInfo:nil
                  repeats:TRUE];

-(void)animationStart{
switch (count) {
    case 0:
        //205   198 115
        count++;
        lbl.textColor=[UIColor colorWithRed:205.0f/255.0f green:198.0f/255.0f blue:115.0f/255.0f alpha:1];

        break;
    case 1:
         count++;
        //205   198 115 56  142 142
        lbl.textColor=[UIColor colorWithRed:56.0f/255.0f green:142.0f/255.0f blue:142.0f/255.0f alpha:1];

        break;
    case 2:
         count++;
        //205   198 115
        lbl.textColor=[UIColor colorWithRed:205.0f/255.0f green:205.0f/255.0f blue:0.0f/255.0f alpha:1];

        break;
    case 3:
         count++;
        //205   198 115 84  255 159
        lbl.textColor=[UIColor colorWithRed:84.0f/255.0f green:255.0f/255.0f blue:159.0f/255.0f alpha:1];

        break;
    case 4:
         count++;
        //205   198 115 255 193 37
        lbl.textColor=[UIColor colorWithRed:255.0f/255.0f green:193.0f/255.0f blue:37.0f/255.0f alpha:1];

        break;
    case 5:
         count++;
        //205   198 115 205 200 177
        lbl.textColor=[UIColor colorWithRed:205.0f/255.0f green:200.0f/255.0f blue:117.0f/255.0f alpha:1];

        break;
    case 6:
         count++;
        //205   198 115 255 228 181
        lbl.textColor=[UIColor colorWithRed:255.0f/255.0f green:228.0f/255.0f blue:181.0f/255.0f alpha:1];

        break;
    case 7:
         count++;
        //205   198 115 233 150 122
        lbl.textColor=[UIColor colorWithRed:233.0f/255.0f green:150.0f/255.0f blue:122.0f/255.0f alpha:1];

        break;
    case 8:
        count++;
        //205   198 115 233 150 122
        lbl.textColor=[UIColor colorWithRed:255.0f/255.0f green:200.0f/255.0f blue:200.0f/255.0f alpha:1];

        break;
    case 9:
         count=0;
        //205   198 115 255 99  71 255  48  48
        lbl.textColor=[UIColor colorWithRed:255.0f/255.0f green:48.0f/255.0f blue:48.0f/255.0f alpha:1];

        break;

    default:
        break;
}

}

Answer 4

A different approch but works. Blinking only for 3 seconds

extension UIView {
  func blink() {
    let animation = CABasicAnimation(keyPath: "opacity")
    animation.isRemovedOnCompletion = false
    animation.fromValue           = 1
    animation.toValue             = 0
    animation.duration            = 0.8
    animation.autoreverses        = true
    animation.repeatCount         = 3
    animation.beginTime           = CACurrentMediaTime() + 0.5
    self.layer.add(animation, forKey: nil)
    }
}

Answer 5

This is how it worked for me. I adapted the answer of @flex_elektro_deimling

First parameter UIView.animateWithDuration is the total time of the animation (In my case I've set it to 0.5), you may set different values on the first and second (delay) to change the blinking speed.

    self.YOURLABEL.alpha = 0;
    UIView.animateWithDuration(
        0.5, 
        delay: 0.2, 
        options: UIViewAnimationOptions.Repeat | UIViewAnimationOptions.Autoreverse, animations: {
            self.YOURLABEL.alpha = 1
        },
        completion:nil)

Answer 6

Got stuck when trying with swift and using multiple options but this seems to work nicely:

    self.cursorLabel.alpha = 1
    UIView.animateWithDuration(0.7, delay: 0.0, options: [.Repeat, .Autoreverse, .CurveEaseInOut], animations:
    {
       self.cursorLabel.alpha = 0
    }, completion: nil)