更改UIView旋转将更改其框架大小。旋转后如何保持镜框尺寸？ [英] Changing UIView rotation will change it's frame size. How to keep frame size after rotating?

问题描述

我通过 UIRotationGestureRecognizer 旋转 UIView ，但是我有一个问题，旋转的 UIView 的帧大小将在旋转时更改。

I'm rotating UIView by the UIRotationGestureRecognizer but I have a problem, The rotated UIView's frame size will be changed on rotation.

targetView = UIView(frame: CGRect(x: self.view.center.x, y: self.view.center.y , width: 100, height: 100))
targetView.backgroundColor = .red
targetView.isUserInteractionEnabled = true
self.view.addSubview(targetView)

targetView.center = self.view.center

let rotate = UIRotationGestureRecognizer(target: self, action: #selector(rotatedView))
targetView.addGestureRecognizer(rotate)

以下是旋转函数：

@objc func rotatedView(_ sender: UIRotationGestureRecognizer) {
var originalRotation = CGFloat()
if sender.state == .began {
    sender.rotation = lastRotation 
    originalRotation = sender.rotation

    print("TargetView Frame Size: [START ROTATE] ", self.targetView.frame.size)
    print("TargetView Bounse Size: [START ROTATE] ", self.targetView.bounds)

} else if sender.state == .changed {
    let newRotation = sender.rotation + originalRotation
    sender.view?.transform = CGAffineTransform(rotationAngle: newRotation)

    print("TargetView Frame Size: [ROTATETING] ", self.targetView.frame.size)
    print("TargetView Bounse Size: [ROTATING ROTATE] ", self.targetView.bounds)
    }
}

大小将更改：

TargetView Frame Size: [START ROTATE]  (100.0, 100.0)
TargetView Frame Size: [ROTATETING]  (110.564206726133, 110.564206726133)

如何像开始旋转一样保持旋转后的框架大小？！

How to keep frame size after rotating just like Start Rotating?!

编辑：

我同时具有以下手势：旋转，调整大小，移动。

I have these gestures together: Rotate, Resize, Move.

移动效果很好，但旋转更改了大小。我可以在此处使用边界，但是如果我也调整大小，则边界不再有用。

Move is working well, but Rotate is changing size. I can use bounds here but If I resize too, the bounds is not useful anymore.

推荐答案

您需要缩放但不旋转的视图大小。您可以从视图的 bounds.size 和 transform 进行计算。

You need the scaled but non-rotated view size. You can compute that from the bounds.size of the view and the transform.

示例

let view = UIView(frame: CGRect(x: 0, y: 0, width: 100, height: 150))

// Scale view by 3X horizontally and by 4X vertically and
// rotate by 45 degrees
view.transform = CGAffineTransform(scaleX: 3, y: 4).rotated(by: 45.0 / 180.0 * .pi)

let transform = view.transform

// Find the angle, print it in degrees
let angle = atan2(-transform.c, transform.a)
print(angle * 180.0 / .pi) // 44.99999999999999

// Find scaleX and scaleY
let scaleX = transform.a * cos(angle) - transform.c * sin(angle)
let scaleY = transform.d * cos(angle) + transform.b * sin(angle)
print(scaleX) // 3.0
print(scaleY) // 4.0

print(view.frame.size)  // (530.3300858899106, 707.1067811865476)
print(view.bounds.size) // (100.0, 150.0)

let adjustedSize = CGSize(width: view.bounds.size.width * scaleX, height: view.bounds.size.height * scaleY)

// print non-rotated but scaled size
print(adjustedSize) // (300.0, 600.0)

---

这是一个方便的扩展，适用于缩放，旋转和平移（移动）的视图：

---

Here it is as a handy extension that will work for views that are scaled, rotated, and translated (moved):

extension CGAffineTransform {
    var angle: CGFloat { return atan2(-self.c, self.a) }

    var angleInDegrees: CGFloat { return self.angle * 180 / .pi }

    var scaleX: CGFloat {
        let angle = self.angle
        return self.a * cos(angle) - self.c * sin(angle)
    }

    var scaleY: CGFloat {
        let angle = self.angle
        return self.d * cos(angle) + self.b * sin(angle)
    }
}

现在，如果您有UIView：

Now, if you have a UIView:

let angle = view.transform.angleInDegrees
let scaleX = view.transform.scaleX
let scaleY = view.transform.scaleY
let adjustedSize = CGSize(width: view.bounds.size.width * scaleX, height: view.bounds.size.height * scaleY)

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