How to know the current scale of a UIView?

Question

How do you find the current scale (zoom level) of a UIView?

Answer 1

If you're applying a scale transform to your view, that transform will be available (appropriately enough) through the transform property on UIView. According to the CGAffineTransform docs, scale transforms will have nonzero values at coordinates (1,1) and (2,2) in the transform matrix; you can therefore get your x- and y-scale factors by doing:

CGFloat xScale = view.transform.a;
CGFloat yScale = view.transform.d;