Creating a custom UIView that just acts just as a gif

Question

I'm rather new to iOS programming and Objective-C in general.

What I have is a bunch of images named "image0.png", "image1.png", ... ,"image47.png" that form an animated image. First I created a button that when pressed, began the animation.

@property (nonatomic, strong) IBOutlet UIImageView *imageView;

...

- (IBAction)startAnimation {
  self.imageView.animationImages = [NSArray array];
  for (int i = 0; i < 48; ++i) {
    NSString *imageName = [NSString stringWithFormat:@"image%i.png", i];
    UIImage *image = [UIImage imageNamed:imageName];
    self.imageView.animationImages = [self.imageView.animationImages arrayByAddingObject:image];
  }
  self.imageView.animationDuration = 5.0;
  [self.imageView startAnimating];
}

This worked perfectly fine, except you had to press the button to start. I wanted the animated image to begin immediately without having to press anything. What I tried to do was give the imageView a custom UIImageView class. Then in the customImageView.m file I shoved the above code into the initWithFrame: method.

- (id)initWithFrame:(CGRect)frame
{
  self = [super initWithFrame:frame];
  if (self) {
    self.animationImages = [NSArray array];
    for (int i = 0; i < 48; ++i)
      self.animationImages = [self.animationImages arrayByAddingObject:[UIImage imageNamed:[NSString stringWithFormat:@"image%i.png", i]]];
    self.animationDuration = 5.0;
    [self startAnimating];
  }
  return self;
}

However, now nothing happens. I've also tried moving the [self startAnimating] line back to an IBAction, but still nothing.

Answer 1

Put the code you have in startAnimation into ViewDidAppear instead. It will start animating as soon as the controller's view appears.

Answer 2

if you dont want to call this method on viewWillAppear. You can also do this.

 - (void)viewDidLoad{
     [self performSelector:@selector(startAnimating) withObject:nil afterDelay:0.3];
}