如何将UIImageView旋转20度？

Question

如果我需要旋转一个,我该UIImageView怎么办？我有一个UIImage我要旋转20度.

Apple文档谈论转换矩阵,但这听起来很难.是否有任何有用的方法或功能来实现这一目标？

Answer 1

如果要向右转,如果要向左旋转,则值必须大于0,并使用符号" - "表示值.例如-20.

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

斯威夫特4:

let degrees: CGFloat = 20.0 //the value in degrees
let radians: CGFloat = degrees * (.pi / 180)
imageView.transform = CGAffineTransform(rotationAngle: radians)

Answer 2

转换矩阵并不难以置信.如果你使用提供的函数,这很简单:

imgView.transform = CGAffineTransformMakeRotation(.34906585);

(.34906585是弧度20度)

Answer 3

Swift版本:

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

Answer 4

斯威夫特 4.0

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