我有一个UIView,我想通过平移和缩放手势来缩放和旋转。但是问题是,当我缩放视图时,然后旋转时,它会在缩放之前重新调整为初始值。
extension UIView {
func addPinchGesture() {
var pinchGesture = UIPinchGestureRecognizer()
pinchGesture = UIPinchGestureRecognizer(target: self,
action: #selector(handlePinchGesture(_:)))
self.addGestureRecognizer(pinchGesture)
}
@objc func handlePinchGesture(_ sender: UIPinchGestureRecognizer) {
self.transform = self.transform.scaledBy(x: sender.scale, y: sender.scale)
sender.scale = 1
}
}
// ROTATION
extension UIView {
func addRotationGesture() {
var rotationGesture = RotationGestureRecognizer()
rotationGesture = RotationGestureRecognizer(target: self,
action: #selector(handleRotationGesture(_:)))
self.addGestureRecognizer(rotationGesture)
}
@objc func handleRotationGesture(_ sender: RotationGestureRecognizer) {
var originalRotation = CGFloat()
switch sender.state {
case .began:
sender.rotation = sender.lastRotation
originalRotation = sender.rotation
case .changed:
let newRotation = sender.rotation + originalRotation
self.transform = CGAffineTransform(rotationAngle: newRotation) // Rotation is fine but it is resizing view
// self.transform = self.transform.rotated(by: newRotation / CGFloat(180 * Double.pi)) // NOT WORKING i.e. irregular rotation
case .ended:
sender.lastRotation = sender.rotation
default:
break
}
}
}
我希望它可以旋转而不影响视图大小。我该如何实现?
答案 0 :(得分:1)
您正在应用旋转变换时重置视图的比例变换。创建一个属性以保留视图的原始比例。
var currentScale: CGFloat = 0
并且在完成捏后,将currentScale值存储到当前比例。然后,在旋转时,在应用旋转之前,也请使用此比例尺。
let scaleTransform = CGAffineTransform(scaleX: currentScale, y: currentScale)
let concatenatedTransform = scaleTransform.rotated(by: newRotation)
self.transform = concatenatedTransform
您正在使用扩展程序添加手势识别器,因此无法存储currentScale。您还可以从当前变换值获取视图的比例值。这是您的代码的样子,
extension UIView {
var currentScale: CGPoint {
let a = transform.a
let b = transform.b
let c = transform.c
let d = transform.d
let sx = sqrt(a * a + b * b)
let sy = sqrt(c * c + d * d)
return CGPoint(x: sx, y: sy)
}
func addPinchGesture() {
var pinchGesture = UIPinchGestureRecognizer()
pinchGesture = UIPinchGestureRecognizer(target: self,
action: #selector(handlePinchGesture(_:)))
self.addGestureRecognizer(pinchGesture)
}
@objc func handlePinchGesture(_ sender: UIPinchGestureRecognizer) {
self.transform = self.transform.scaledBy(x: sender.scale, y: sender.scale)
sender.scale = 1
}
}
// ROTATION
extension UIView {
func addRotationGesture() {
var rotationGesture = RotationGestureRecognizer()
rotationGesture = RotationGestureRecognizer(target: self,
action: #selector(handleRotationGesture(_:)))
self.addGestureRecognizer(rotationGesture)
}
@objc func handleRotationGesture(_ sender: RotationGestureRecognizer) {
var originalRotation = CGFloat()
switch sender.state {
case .began:
sender.rotation = sender.lastRotation
originalRotation = sender.rotation
case .changed:
let scale = CGAffineTransform(scaleX: currentScale.x, y: currentScale.y)
let newRotation = sender.rotation + originalRotation
self.transform = scale.rotated(by: newRotation)
case .ended:
sender.lastRotation = sender.rotation
default:
break
}
}
}
我用这个answer作为提取比例值的参考。
答案 1 :(得分:0)
我面临着同样的问题一旦用手指捏住,然后从按钮旋转后,它会自动从当前比例缩小,但我在下面设置了逻辑。
1111