Get the current angle/rotation/radian for a UIView?

问题

How do you get the current angle/rotation/radian a UIView has?

回答1:

You can do it this way...

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

回答2:

Swift:

// Note the type reference as Swift is now string Strict

let radians:Double = atan2( Double(yourView.transform.b), Double(yourView.transform.a))
let degrees:CGFloat = radians * (CGFloat(180) / CGFloat(M_PI) )

回答3:

For Swift 3, you could use the following code:

let radians:Float = atan2f(Float(view.transform.b), Float(view.transform.a))
let degrees:Float = radians * Float(180 / M_PI)

回答4:

A lot of the other answers reference atan2f, but given that we're operating on CGFloats, we can just use atan2 and skip the unnecessary intermediate cast:

Swift 4:

let radians = atan2(yourView.transform.b, yourView.transform.a)
let degrees = radians * 180 / .pi

回答5:

//For Swift 3: M_PI is depreciated now Use Double.pi

let radians = atan2f(Float(yourView.transform.b), Float(yourView.transform.a));
let degrees = radians * Float(180 / Double.pi)

//For Swift 4:

let radians = atan2(yourView.transform.b, yourView.transform.a)
let degrees = radians * 180 / .pi

回答6:

In swift 2 and Xcode 7 :

let RdnVal = CGFloat(atan2f(Float(NamVyu.transform.b), Float(NamVyu.transform.a)))
let DgrVal = RdnVal * CGFloat(180 / M_PI)

来源：https://stackoverflow.com/questions/5754877/get-the-current-angle-rotation-radian-for-a-uiview