将UIImageView从左移到中心

Question

I want to move my image view from left to the center of the view.

Following is my code:

CGPoint origin = self.headerImage.center;
CGPoint target = CGPointMake(0, self.headerImage.center.x);

CABasicAnimation *bounce = [CABasicAnimation animationWithKeyPath:@"position.x"];
bounce.fromValue = [NSNumber numberWithInt:origin.x];
bounce.toValue = [NSNumber numberWithInt:target.x];
[self.headerImage.layer addAnimation:bounce forKey:@"position"];

It has to start moving from the left and stop at the center when the view controller is loaded. But it is not working properly. How can I sort this out?

Answer 1

Use

[UIView animateWithDuration:1.0 animations:^{
    headerImage.frame = myNewFrameRect;
}];

Answer 2

1. target needs to indicate the center of the view: CGPointMake(self.view.center.x, self.view.center.y)
2. Change fillMode removedOnCompletion autoreverses repeatCount to avoid frame changes (final of animation)

Final code:

CGPoint origin = self.headerImage.center;
CGPoint target = CGPointMake(self.view.center.x, self.view.center.y);
CABasicAnimation *bounce = [CABasicAnimation animationWithKeyPath:@"position.x"];
bounce.duration = 1;
bounce.fromValue = [NSNumber numberWithInt:origin.x];
bounce.toValue = [NSNumber numberWithInt:target.x];
bounce.fillMode = kCAFillModeForwards;
bounce.removedOnCompletion = NO;
bounce.autoreverses = NO;
bounce.repeatCount = 0;
[self.headerImage.layer addAnimation:bounce forKey:@"position"];
CGAffineTransform transform = CGAffineTransformMakeScale(1.3, 1.3);
self.headerImage.transform = transform;

Answer 3

The problem is here :

CGPoint origin = self.headerImage.center;
CGPoint target = CGPointMake(0, self.headerImage.center.x);

You're not aiming at the correct target, you're aiming at the current center of your headerImage ; so technically, origin and target are the same location here.

Move the target to the center of the superview, and you'll be good :)

CGPoint target = CGPointMake(0, self.headerImage.superView.center.x);

You could also probably use self.view.center.x , but it's slightly less future proof.

Also, I've noticed the keys you're using differ between the two times you use it ("position" and "position.x"). I'm not super comfortable with CAAnimations, so this might be completely right in the first place