UIView animation is not working as expected - ios

Question

I have two UIImageView filling the view controller, the first is filling the top half, and the second for the bottom half. I set them directly in the storyboard file.
In the viewDidLoad method, i am setting code in order to perform animation for the two UIImageView, so that it will look like a basket which gets opened (the first UIImageView moved to the top until it gets out of the view, and the second UIImageView moved to the bottom of the view until it gets out of the view).
This is my code so far:
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
CGRect basketTopFrame = self.basketTop.frame;
basketTopFrame.origin.y = -basketTopFrame.size.height;
CGRect basketBottomFrame = self.basketBottom.frame;
basketBottomFrame.origin.y = self.view.bounds.size.height;
[UIView beginAnimations:nil context:nil];
[UIView setAnimationDuration:0.5];
[UIView setAnimationDelay:1.0];
[UIView setAnimationCurve:UIViewAnimationCurveEaseOut];
self.basketTop.frame = basketTopFrame;
self.basketBottom.frame = basketBottomFrame;
[UIView commitAnimations];
}
But the behavior is different than i was expecting, the top frame is not moving, and the bottom frame is animated from top left to bottom (origin position, and not moving out of the view).
This is UIImageViews position as i set in the storyboard:
This is the UIImageViews when i launch the app:
And this is the UIImageViews when the app finish the animation(viewDidLoad):
Please note that this code works in Xcode 4.2, but since upgrading to Xcode 4.5 and using Storyboard, i begin getting this issue. Thanx in advance.

Answer 1

You may have auto layout enabled on your storyboard. In this case the view components will not have a valid frame value at viewDidLoad, so your code won't work.
You can disable auto layout by selecting the file inspector in the storyboard and unchecking "Use Autolayout".
In any case, that is the wrong method to be starting an animation from. Try moving the code to viewDidAppear.

Answer 2

Once you have "AutoLayout" turned off and if you are targeting IOS 4 and later than block based UIView animation is recommended by Apple as it simplifies the process and you can do things in one line. Please check UIView Reference for further information.
In your case , whether you plan to do the animation in ViewDidLoad / ViewWillAppear, it can be done in the following way using block based animation:
CGRect basketTopFrame = self.boxTop.frame;
CGRect basketBottomFrame = self.boxBottom.frame;
[UIView animateWithDuration: 0.5 delay:0.1 options:UIViewAnimationOptionCurveEaseOut animations:^{
[self.boxTop setFrame:CGRectMake(basketTopFrame.origin.x, -basketTopFrame.size.height, basketTopFrame.size.width, basketTopFrame.size.height)];
[self.boxBottom setFrame:CGRectMake(basketBottomFrame.origin.x, self.view.bounds.size.height, basketBottomFrame.size.width, basketBottomFrame.size.height)];
} completion:^(BOOL finished) {
// TODO : Do any additional stuffs.
}];