Keep back to origin position an UIImageView - ios

Question

I'm now implementing an app, for iOS devices so in objective C, and i was asking how to keep back to origin position an UIImageView after a rotation ?
For example, i use my UIImageView like this :
CGAffineTransform initialPosition = CGAffineTransformMakeRotation(0);
CGAffineTransform finalPosition = CGAffineTransformMakeRotation(M_PI/2);
[UIView beginAnimations: #"Rotate animation" context: NULL];
MySuperUIImageView.transform = initialPosition;
[UIView setAnimationDuration:1.0];
[UIView setAnimationRepeatAutoreverses:NO];
[UIView setAnimationRepeatCount:1];
[UIView setAnimationDelegate:self];
MySuperUIImageView.transform = finalPosition;
[UIView commitAnimations];
But after, i made it desappear for a time, using :
MySuperUIImageView.alpha = 0.0f;
And when i re-use it, i want it to be in the first original position, with no rotation. Is it possible easily ?
Thanks in advance !

Answer 1

Yes. Very easily:
MySuperUIImageView.transform = CGAffineTransformIdentity;

Answer 2

Actually, there is. Since you're applying an affine transform to the view, you can reset all transforms applied to the view by setting its transform to CGAffineTransformIdentity which applies an identity transform matrix:
1 - 0 - 0
0 - 1 - 0
0 - 0 - 1
[mySuperUIImageView setTransform:CGAffineTransformIdentity];
Note: In Objective C, the convention is to start class names with a capital letter, and instances with a lower case.
As of iOS 4, Apple recommends using block based UIView animation. Here's an example of what I believe you're trying to attempt using updated code.
CGAffineTransform finalPosition = CGAffineTransformMakeRotation(M_PI/2);
[UIView animateWithDuration:1.0 delay:0.0 options:kNilOptions animations:^{
[mySuperUIImageView setTransform:finalPosition];
} completion:^(BOOL finished) {
[mySuperUIImageView setTransform:CGAffineTransformIdentity];
}];