UIImageView shifts left before animating to the right - objective-c

Question

Newbie here,
With this code in the .m file I aimed to animate an UIImageView to the right
#interface ViewController ()
#property (strong, nonatomic) IBOutlet UIImageView *myImageView;
#end
#implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
[UIView animateWithDuration:1
delay:0
options:UIViewAnimationOptionCurveEaseInOut
animations:^{
self.myImageView.center = CGPointMake(self.myImageView.center.x + 100, self.myImageView.center.y);
}
completion:^(BOOL finished){
}];
}
But what actually happens is that the image view shifts 100 points to the left and then animates to the right by 100 points back to its original position. I don't know why this happens. How can I achieve an animation that moves directly to the right?
Note: I'm not sure if this has to do with anything, but I added constraints in the interface builder to center this UIImageView in the middle.

Answer 1

Create IBOutlets for the constraints you want change. Just like you would for any other UIKit element. Then in your code instead of doing:
self.myImageView.center = CGPointMake(self.myImageView.center.x + 100, self.myImageView.center.y);
Do something like this:
self.imageViewTralingSpaceConstraint.constant = 100; //Or whatever value makes sense
Then in your animateWithDuration block add [self.view layoutSubViews];

Answer 2

you probably want to put this code in your viewDidAppear method rather than your viewDidLoad. this would make the animation happen after the view appears rather than before it. the viewDidLoad method is called after the view hierarchy is loaded into memory but not neccessarily after it is all laid out.
here is a link to the uiviewcontroller reference. https://developer.apple.com/library/ios/documentation/UIKit/Reference/UIViewController_Class/
check out these two methods there. if you continue doing iOS development you will get to know these methods really well.