Question

我有一个来自一个类的视图，我想将角半径设置为等于宽度的一半。

宽度是使用autolayout创建的计算属性。所以通常我会在viewWillLayoutSubviews()中设置角半径属性，如此

override func viewWillLayoutSubviews() {
    super.viewWillLayoutSubviews()

    c.largeProfileImage.layer.cornerRadius = c.largeProfileImage.frame.width / 2
}

但是largeProfileImage不是它在viewdidLoad之后调用的初始视图，我在点击手势上为它设置动画。下面是视图在屏幕上的动画。它是在同一个函数中创建的。

     //I tried setting the cornerRadius here as well but it isn't setting.

    //c.largeProfileImage.layer.cornerRadius = c.largeProfileImage.frame.width / 2


    self.view.layoutIfNeeded()

    UIView.animate(withDuration: 0.5, delay: 0, usingSpringWithDamping: 0.8, initialSpringVelocity: 0, options: .curveEaseOut, animations: {

        self.profileImageContainerCenterY?.constant = -(c.profileImageContainer.frame.height) * 2
        self.profileSettingsContainerCenterY?.constant = 0

        c.profileSettingsContainer.alpha = 1
        c.largeProfileImage.alpha = 1

        self.view.layoutIfNeeded()
    }, completion: { (completed) in
        self.view.layoutIfNeeded()
})

修改

这是profileImage

let largeProfileImage: UIImageView = {
    let pv = UIImageView()
    pv.contentMode = .scaleAspectFill
    pv.layer.masksToBounds = true
    pv.clipsToBounds = true
    pv.image = UIImage(named: "user")

    pv.translatesAutoresizingMaskIntoConstraints = false
    return pv
}()

Answer 1

我能够成功调试此问题。

由于宽度是计算属性，因此在布局布局之前它为0意味着

c.largeProfileImage.layer.cornerRadius = c.largeProfileImage.frame.width / 2

self.view.layoutIfNeeded()

导致圆角半径为零。

所以解决方案......

之后调用它的宽度是在计算宽度后设置角半径。

self.view.layoutIfNeeded()

c.largeProfileImage.layer.cornerRadius = c.largeProfileImage.frame.width / 2

Answer 2

为了正确的动画，改变这样的序列。

    self.profileImageContainerCenterY?.constant = -(c.profileImageContainer.frame.height) * 2
    self.profileSettingsContainerCenterY?.constant = 0
UIView.animate(withDuration: 0.5, delay: 0, usingSpringWithDamping: 0.8, initialSpringVelocity: 0, options: .curveEaseOut, animations: {
    c.profileSettingsContainer.alpha = 1
    c.largeProfileImage.alpha = 1
    self.view.layoutIfNeeded()
}, completion: nil)

Answer 3

以下三行是获得圆形图像所必需的 -

image.layer.cornerRadius = image.frame.width / 2
image.layer.masksToBounds = false
image.clipsToBounds = true

您可能会看到一个四舍五入的UIImage，但您可能还会注意到圆圈内的图像平方并解决了您可能已经使用contentMode。大部分时间.scaleAspectFill都能胜任。

在视图加载后在视图上设置角半径

3 个答案: