How can I rotate UIImageView by 20 degrees?

Question

What should I do if I need to rotate a UIImageView ? I have a UIImage that I want to rotate 20 degrees.

Apple docs talk about conversion matrix, but it sounds complicated. Are there any useful methods or functions to achieve this?

Answer 1

The transformation matrix is ​​not incredibly complex. It is quite simple if you use the supplied functions:

 imgView.transform = CGAffineTransformMakeRotation(.34906585); 

(34906585 - 20 degrees in radians)

Answer 2

If you want to turn right, the value must be greater than 0, if you want to turn left, indicates a value with a "-" sign. For example, -20.

 CGFloat degrees = 20.0f; //the value in degrees CGFloat radians = degrees * M_PI/180; imageView.transform = CGAffineTransformMakeRotation(radians); 

Answer 3

Quick version:

 let degrees:CGFloat = 20 myImageView.transform = CGAffineTransformMakeRotation(degrees * CGFloat(M_PI/180) ) 

Answer 4

Swift 4.0

 imageView.transform = CGAffineTransform(rotationAngle: CGFloat(20.0 * Double.pi / 180)) 

Answer 5

 _YourImageView.transform = CGAffineTransformMakeRotation (1.57);

where 1.57 is the radian value for 90 degrees

Answer 6

This is a simpler formatting example (for 20 degrees):

 CGAffineTransform(rotationAngle: ((20.0 * CGFloat(M_PI)) / 180.0)) 

Answer 7

Here is the extension for Swift 3.

 extension UIImageView { func rotate(degrees:CGFloat){ self.transform = CGAffineTransform(rotationAngle: degrees * CGFloat(M_PI/180)) } } 

Using:

 myImageView.rotate(degrees: 20) 

Answer 8

As far as I know, using a matrix in UIAffineTransform is the only way to achieve rotation without the help of a third-party structure.