ios - 如何在旋转中使用 TapGestureRecognizer 处理 UIImage

Question

我有一个标签和 UIImage 布局，如下所示。

LabelMonth ImgArrowDown

这个 LabelMonth 有如下的 TapGestureRecognizer。

当用户点击 LabelMonth 时，ImageArrowDown 将旋转 360，使其看起来向上。

问题:

• 当用户再次点击 LabelMonth 时，如何将 ImageArrowDown 旋转回其原始位置，即箭头指向下方？
  

viewDidLoad(){

    let tapGestureRecognizer = UITapGestureRecognizer(target:self, action:
        #selector(HandleImgRotation))

    LabelMonth.isUserInteractionEnabled = true LabelMonth.addGestureRecognizer(tapGestureRecognizer)

    }




    func HandleImgRotation(_sender:AnyObject){

    UIView.animate(withDuration:1.0, animations: ({self.imgArrowDown.transform = CGAffineTransform(rotationAngle: self.radian(degree:360))
                          }))

    }



    func radian(degrees:Double) -> CGFloat{

    return CGFloat(degrees * .pi/degrees) 

    }

谢谢

Answer 1

以下方法应该可以解决您的问题...

var rotated = false

func HandleImgRotation() {
        UIView.animate(withDuration: 2.0) {
            if !self.rotated {
                UIView.animate(withDuration:1.0, animations: ({
                    ImgArrowDown.transform = CGAffineTransform(rotationAngle: CGFloat(M_PI * 0.999) )
                    self.rotated = true
                }))
            } else {
                UIView.animate(withDuration:1.0, animations: ({
                    ImgArrowDown.transform = CGAffineTransform.identity
                    self.rotated = false
                }))
            }
        }
    }