UIButton Frame changed After Move from one Position To Another

问题

I have 1 UIButton in StoryBoard like below screen and I move UIButton from one position to another position by following this Answer.

Edit

Another thing that I want to rotate UIButton and for that I have tried below code and it works fine but after rotating UIButton when I try to move UIButton position from 1 place to another then UIButton frame is changed.

Entire UIButton code.

class DraggableButton: UIButton {

var localTouchPosition : CGPoint?
var lastRotation: CGFloat = 0

required init?(coder aDecoder: NSCoder) {
    super.init(coder: aDecoder)

    // ROTATION CODE
    let rotate = UIRotationGestureRecognizer(target: self, action:#selector(rotatedView(_:)))
    self.addGestureRecognizer(rotate)
}

// SCROLLING CONTENT FROM ONE POSITION TO ANOTHER
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
    super.touchesBegan(touches, with: event)
    let touch = touches.first
    self.localTouchPosition = touch?.preciseLocation(in: self)
}

override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
    super.touchesMoved(touches, with: event)
    let touch = touches.first
    guard let location = touch?.location(in: self.superview), let localTouchPosition = self.localTouchPosition else{
        return
    }

    self.frame.origin = CGPoint(x: location.x - localTouchPosition.x, y: location.y - localTouchPosition.y)
    print(self.frame)
}

override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
    super.touchesEnded(touches, with: event)
    self.localTouchPosition = nil
}

override func touchesCancelled(_ touches: Set<UITouch>, with event: UIEvent?) {
    super.touchesCancelled(touches, with: event)
    self.localTouchPosition = nil
}

// ROTATION CODE
@objc func rotatedView(_ sender: UIRotationGestureRecognizer) {
    var originalRotation = CGFloat()
    if sender.state == .began {
        sender.rotation = lastRotation
        originalRotation = sender.rotation
    } else if sender.state == .changed {
        let newRotation = sender.rotation + originalRotation
        sender.view?.transform = CGAffineTransform(rotationAngle: newRotation)
        } else if sender.state == .ended {
            lastRotation = sender.rotation
        }
    }
}

Edit 1

I uploaded issue video.

Edit 2

If I used UIButton Rotation and Movement Code separately then it works but when I write both code it generate this issue.

回答1:

I believe the issue is that the rotation is about the center of the view, so when you apply the rotation the frame size increases which throws off the distance relative to the origin of the frame.

I was able to fix this by moving the view relative to its center:

override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
    super.touchesBegan(touches, with: event)
    let touch = touches.first
    guard let location = touch?.location(in: self.superview) else { return }

    // Store localTouchPosition relative to center
    self.localTouchPosition = CGPoint(x: location.x - self.center.x, y: location.y - self.center.y)
}

override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
    super.touchesMoved(touches, with: event)
    let touch = touches.first
    guard let location = touch?.location(in: self.superview), let localTouchPosition = self.localTouchPosition else{
        return
    }

    self.center = CGPoint(x: location.x - localTouchPosition.x, y: location.y - localTouchPosition.y)
    print(self.frame)
}

来源：https://stackoverflow.com/questions/51337323/uibutton-frame-changed-after-move-from-one-position-to-another

标签

ios

swift

uibutton

rotation