How to rotate UIViews?

Question

The Twitter app is a tab bar app on the iPhone. Nothing in any of the tabs will rotate, yet, when you click on a link from a tweet, the view controller that is pushed on top of it IS allowed to rotate. The only rotations I have ever doe is from tilting the device, landscape or portrait, but I don't understand how to use 2d transformations and animations to rotate views.

How do you rotate any view with that's a subclass of UIView?

Answer 1

You can use UIView animations and Transform methods. For rotating 90 degrees:

[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:0.5];

imageView.transform = CGAffineTransformMakeRotation(M_PI_2);

[UIView commitAnimations];