Animation of scrolling in collectionview in ios - ios

Question

I have one one collectionview in that I have 10 images loaded from webservice. I want to autoscroll that imageview from 1st to last position and then last to 1st position continuously whenever that page appears.
I use below method
-(void)scrollSlowly
{
CATransition *transition = [CATransition animation];
transition.duration = 4.0f;
transition.type = kCATransitionPush;
transition.subtype = kCATransitionFromLeft;
[transition setTimingFunction:[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut]];
[UIView animateWithDuration:5.0f
delay:3.0f
options:UIViewAnimationOptionRepeat | UIViewAnimationOptionAutoreverse
animations:^{
[self.CollectionView setContentOffset:CGPointMake(CGFLOAT_MAX ,0)];
}
completion:nil];
[self.CollectionView.layer addAnimation:transition forKey:#"transition"];
}
-(void)scrollSlowlyToPoint
{
self.CollectionView.contentOffset = self.scrollingPoint;
// Here you have to respond to user interactions or else the scrolling will not stop until it reaches the endPoint.
if (CGPointEqualToPoint(self.scrollingPoint, self.endPoint))
{
[self.scrollingTimer invalidate];
}
// Going one pixel to the right.
self.scrollingPoint = CGPointMake(self.scrollingPoint.x+1, self.scrollingPoint.y);
}
I want to autoscroll horizontally in Objective-C. thanks in advance

Answer 1

Create a custom UICollectionViewCell class, create and connect an outlet for image view.
In .h file:
NSMutableArray *imgArr;
NSInteger testIndexPath;
I guess you can implement the datasource methods for UICollectionView.
In cellForItemAtIndexPath add this line after adding images to the imageview
testIndexPath=indexPath.row;//this will give you the indexPath for cell
Now add this two methods in your .m file:
-(void)autoScroll{
CGFloat point = self.collectionVw.contentOffset.x;
CGFloat lo = point + 1;
[UIView animateWithDuration:0 delay:0 options:UIViewAnimationOptionCurveEaseIn animations:^{
self.collectionVw.contentOffset = CGPointMake(lo, 0);
}completion:^(BOOL finished){
if (testIndexPath==8)
{
[self autoScrollReverse];
}
else{
[self autoScroll];
}
}];
}
-(void)autoScrollReverse{
CGFloat point = self.collectionVw.contentOffset.x;
CGFloat lo = point - 1;
[UIView animateWithDuration:0 delay:0 options:UIViewAnimationOptionCurveEaseIn animations:^{
self.collectionVw.contentOffset = CGPointMake(lo, 0);
}completion:^(BOOL finished){
if(testIndexPath == 0){
[self autoScroll];
}else{
[self autoScrollReverse];
}
}];
}
//Call [self autoScroll] in your viewDidLoad

Answer 2

Better way to scroll index from top to bottom and bottom to top.
This will move to index 10 means scroll top to bottom
[self.collectionView scrollToItemAtIndexPath:[NSIndexPath indexPathForItem:9 inSection:0] atScrollPosition:UICollectionViewScrollPositionNone animated:YES];
For again scroll bottom to top which move to index 0
[UIView animateWithDuration:3
delay:0.1
options:UIViewAnimationOptionCurveEaseInOut
animations:^{
[self.collectionView scrollToItemAtIndexPath:[NSIndexPath indexPathForItem:0 inSection:0] atScrollPosition:UICollectionViewScrollPositionNone animated:YES];
}
completion:nil];
You can also set scrolling from top to bottom in UIVIew animation like above.
Set the first method in ViewWillAppear and set second method in ViewDidAppear if you need animation for every time page appear

Answer 3

Please apply this one. May be its help to you
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
MyCollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:#"MyCollectionViewCell" forIndexPath:indexPath];
[UIView animateWithDuration:0.2 animations:^{
cell.transform = CGAffineTransformMakeTranslation(0.0, -50);
}];
[self delayBy:0.5 code:^{ // call block of code after time interval
[UIView animateWithDuration:0.3 animations:^{
cell.transform = CGAffineTransformIdentity;
}];
}];
return cell;
}

Answer 4

This may help solve your problem:
int maxDelay = 4;
int delayInSeconds = arc4random() % maxDelay;
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(delayInSeconds * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
//your codes//
});