How to programmatically rotate the view by 180 deg

Question

How to programmatically rotate the view by 180 degrees in my iPhone App?

Answer 1

As ’CGAffineTransformRotate’ uses radians as its unit of measure, and 180 degrees is the same as PI, instead of the math provided in other answers you can simply do:

view.transform = CGAffineTransformRotate(view.transform, M_PI);

Swift 3:

view.transform = view.transform.rotated(by: .pi)

If you plan on doing a lot of transforms, it's probably best to read up on radians, so you understand what is going on.

Answer 2

Should be possible by using CGAffineTransform

Quote from this question, this should do the trick:

CGFloat radians = atan2f(yourView.transform.b, yourView.transform.a);
CGFloat degrees = radians * (180 / M_PI);
CGAffineTransform transform = CGAffineTransformMakeRotation((90 + degrees) * M_PI/180);
yourView.transform = transform;

Answer 3

Simple solution:

view.transform = CGAffineTransformMakeRotation(degrees*M_PI/180);

Answer 4

In Swift 3 :

let rotationDegrees =  180.0
let rotationAngle = CGFloat(rotationDegrees * M_PI / 180.0)
view.transform = CGAffineTransform(rotationAngle: rotationAngle)

Answer 5

Latest Swift 3 syntax:

view.transform = view.transform.rotated(by: .pi)

Answer 6

Same outcome as @Manny's answer using a different function.

 CGFloat degreesOfRotation = 180.0;
 view.transform = CGAffineTransformRotate(view.transform,
     degreesOfRotation * M_PI/180.0);