文章目錄：

平面旋轉(zhuǎn)
   順時針旋轉(zhuǎn)90度
   順時針旋轉(zhuǎn)180度
   逆時針旋轉(zhuǎn)90度
   持續(xù)旋轉(zhuǎn)
3D旋轉(zhuǎn)
   向量為(1, 0, 0)時
   向量為(0, 1, 0)時
   向量為(0, 1, 0)時
   持續(xù)旋轉(zhuǎn)

平面旋轉(zhuǎn)：

順時針旋轉(zhuǎn)90度：

            UIView.animate(withDuration: 1) {
                self.captainLabel.transform = CGAffineTransform(rotationAngle: CGFloat.pi / 2)
            }

順時針旋轉(zhuǎn)180度：

            UIView.animate(withDuration: 1) {
                self.captainLabel.transform = CGAffineTransform(rotationAngle: CGFloat.pi)
            }

逆時針旋轉(zhuǎn)90度：

需要用到

    /* Invert `t' and return the result. If `t' has zero determinant, then `t'
       is returned unchanged. */
    /* 對 調(diào)用該方法的 CGAffineTransform實例 進行取反 并返回 */
    @available(iOS 2.0, *)
    public func inverted() -> CGAffineTransform

事例代碼

        UIView.animate(withDuration: 1) {
            self.captainLabel.transform = CGAffineTransform(rotationAngle: CGFloat.pi / 2).inverted()
        }

持續(xù)旋轉(zhuǎn)：

需要用到

    /* 用來讓 CGAffineTransform實例 關(guān)聯(lián)我們指定的 CGAffineTransform 實例 */
    /* Concatenate `t2' to `t1' and return the result:
         t' = t1 * t2 */
    
    @available(iOS 2.0, *)
    public func concatenating(_ t2: CGAffineTransform) -> CGAffineTransform

事例代碼

        Timer.scheduledTimer(withTimeInterval: 1, repeats: true) { (_) in
            UIView.animate(withDuration: 1) {
                self.captainLabel.transform = CGAffineTransform(rotationAngle: CGFloat.pi / 2).inverted().concatenating(self.captainLabel.transform)
            }
        }

3D旋轉(zhuǎn)：

需要用到

/* 對CATransform3D的實例進行變換（向向量(x, y, z)的方向 同時 以向量為軸 旋轉(zhuǎn) angle 角度）并返回新的CATransform3D實例。*/
/* Rotate 't' by 'angle' radians about the vector '(x, y, z)' and return
 * the result. If the vector has zero length the behavior is undefined:
 * t' = rotation(angle, x, y, z) * t. */

@available(iOS 2.0, *)
public func CATransform3DRotate(_ t: CATransform3D, _ angle: CGFloat, _ x: CGFloat, _ y: CGFloat, _ z: CGFloat) -> CATransform3D

向量為(1, 0, 0)時：

            UIView.animate(withDuration: 1) {
                self.captainLabel.layer.transform = CATransform3DMakeRotation(CGFloat.pi, 1, 0, 0)
            }

向量為(0, 1, 0)時：

            UIView.animate(withDuration: 1) {
                self.captainLabel.layer.transform = CATransform3DMakeRotation(CGFloat.pi, 0, 1, 0)
            }

向量為(0, 0, 1)時：

            UIView.animate(withDuration: 1) {
                self.captainLabel.layer.transform = CATransform3DMakeRotation(CGFloat.pi, 0, 0, 1)
            }

持續(xù)旋轉(zhuǎn)：

        Timer.scheduledTimer(withTimeInterval: 1, repeats: true) { (_) in
            UIView.animate(withDuration: 1) {
                self.captainLabel.layer.transform = CATransform3DRotate(self.captainLabel.layer.transform, CGFloat.pi / 2, 1, 0, 0)
            }
        }