UIView.animateWithDuration swift 3

Question

按下按钮时可以正常工作.单击此功能后显示另一个视图

@IBAction func charSetPressed(_ button: UIButton) {
    if button.titleLabel!.text == "1/2" {

        charSet1.isHidden = true
        charSet2.isHidden = false

        button.setTitle("2/2", for: .normal)

    } else if button.titleLabel!.text == "2/2" {
        charSet1.isHidden = false
        charSet2.isHidden = true
        button.setTitle("1/2", for: .normal)
    }

    UIView.animateWithDuration(0.2, animations: {

        button.transform = CGAffineTransformScale(CGAffineTransformIdentity, 2.0, 2.0)
        }, completion: {(_) -> Void in(here the error happend)

            button.transform =
            CGAffineTransformScale(CGAffineTransformIdentity, 1, 1)
    })
}

Answer 1

//按键动画显示...(适用于Swift 3.0)

    UIView.animate(withDuration: 0.2, animations: {
        button.transform = CGAffineTransform(scaleX: 2.0, y: 2.0)
    }, completion:{ _ in
        button.transform = CGAffineTransform(scaleX: 1.0, y: 1.0)
    })