Change array of images with NSTimer - objective-c

Question

I want to implement a auto change image gallery. here is my code in the controller. i have a uiimageview named image. i want to link the array of image to my image view to let it auto change after a few seconds. What should i do??
- (void)viewDidLoad{
[super viewDidLoad];
[self performSelector:#selector(changeImage) withObject:nil afterDelay:2];
}
-(void)changeImage {
NSArray *images = [NSArray arrayWithObjects:[UIImage imageNamed:#"animated-fish-1.jpg"], [UIImage imageNamed:#"tumblr_7"], [UIImage imageNamed:#"th_nature_4.jpg"],nil];
image.animationImages = images;
// how to let the array of image load and link to the perform selector??
// what should i continue from here?
}

Answer 1

Store the images in an ivar
#interface YourClass : SomeSuperClass
#property (nonatomic, strong) NSArray *images;
#end
Don't start the timer in viewDidLoad as the view will not be on the screen yet so there is no point - move it to viewDidAppear:
- (void)viewDidLoad
{
[super viewDidLoad];
self.images = #[ ... ]; // or pass these into the class
self.imageView.image = self.images[0];
}
- (void)viewDidAppear:(BOOL)animated
{
[super viewDidAppear:animated];
[NSTimer scheduledTimerWithTimeInterval:2
target:self
selector:#selector(changeImage:)
userInfo:nil
repeats:YES];
}
-(void)changeImage:(NSTimer *)timer
{
NSInteger currentIndex = [self.images indexOfObject:self.imageView.image];
NSInteger nextIndex = (currentIndex + 1) % self.images.count;
self.imageView.image = self.images[nextIndex];
// If for any reason you need to cancel the image rotation
if ([self shouldCancelImageRotation]) {
[timer invalidate];
}
}

Answer 2

To animate the images using timer, try this
- (void)viewDidLoad
{
[super viewDidLoad];
[NSTimer scheduledTimerWithTimeInterval:1
target:self
selector:#selector(animateImages)
userInfo:nil
repeats:YES];
imageCount = 1;
}
-(void)animateImages
{
imageCount = imageCount + 1;
NSString *imageName = [NSString stringWithFormat:#"image%i.png"];
[theImage setImage:[UIImage imageNamed:imageName]];
}

Answer 3

You should use NSTimer, per example, you can use this method :
https://developer.apple.com/library/mac/documentation/Cocoa/Reference/Foundation/Classes/NSTimer_Class/Reference/NSTimer.html#//apple_ref/occ/clm/NSTimer/scheduledTimerWithTimeInterval:target:selector:userInfo:repeats:
This method allow you to define a selector to use and repeats every x seconds

Answer 4

try like this ,
take one global varaible index
- (void)viewDidLoad{
[super viewDidLoad];
index=0;
NSArray *images = [NSArray arrayWithObjects:[UIImage imageNamed:#"animated-fish-1.jpg"], [UIImage imageNamed:#"tumblr_7"], [UIImage imageNamed:#"th_nature_4.jpg"],nil];
imageview.image = [images objectAtIndex:index];
[NSTimer scheduledTimerWithTimeInterval:2.0 target:self selector:#selector(changeImage) userInfo:nil repeats:YES];
}
-(void)changeImage {
index++;
if(index==[images count]){
index=0;
}
imageview.image = [images objectAtIndex:index];
}