Ios 如何设置视图到X和Y中心的动画？

我有一个ImageView，它对

助手标题视图具有centerX和centerY约束，如下图所示


我想设置徽标imageView的动画，使其位于屏幕中心，如下图所示：

我尝试了一些代码，但它不起作用，老实说，我不确定下面的代码，这里是我尝试的。也许你有更好的方法。这是我试过的

首先，我尝试为这两个约束提供标识符：

然后我移除约束并创建一个新的约束，如下面的代码所示：

 UIView.animate(withDuration: 1.1, delay: 0.5, usingSpringWithDamping:  0.4, initialSpringVelocity: 0.0, animations: {

            // remove the initial constraint
            self.mainLogoCenterXConstraint.isActive = false
            self.mainLogoCenterYConstraint.isActive = false

            // create new constraint
            let newMainLogoCenterXConstraint = NSLayoutConstraint(
                item: self.mainLogoImageView,
                attribute: .centerX,
                relatedBy: .equal,
                toItem: self.view,
                attribute: .centerY,
                multiplier: 1.0,
                constant: 0)
            newMainLogoCenterXConstraint.identifier = "mainLogoCenterXConstraint"
            newMainLogoCenterXConstraint.isActive = true

            let newMainLogoCenterYConstraint = NSLayoutConstraint(
                item: self.mainLogoImageView,
                attribute: .centerY,
                relatedBy: .equal,
                toItem: self.view,
                attribute: .centerY,
                multiplier: 1.0,
                constant: 0)
            newMainLogoCenterYConstraint.identifier = "mainLogoCenterYConstraint"
            newMainLogoCenterYConstraint.isActive = true


            self.view.layoutIfNeeded()

        }, completion: nil)

但它崩溃并给出错误：

“NSInvalidLayoutConstraintException”，原因：“约束不正确”
关联不兼容类型的锚：
也许您有更好的方法来实现这一点……
您在创建将
self.mainlogimageview.centerX
关联到
self.view.centerY
的第一个约束时出错-将第二个约束更改为
self.view.centerX
。不能将x轴定位绑定到y轴定位

此外，请确保正确设置动画，检查我关于如何使用autolayout进行设置的答案

就你而言：

// remove the initial constraint
self.mainLogoCenterXConstraint.isActive = false
self.mainLogoCenterYConstraint.isActive = false

// create new constraint
let newMainLogoCenterXConstraint = NSLayoutConstraint(
            item: self.mainLogoImageView,
            attribute: .centerX,
            relatedBy: .equal,
            toItem: self.view,
            attribute: .centerX,
            multiplier: 1.0,
            constant: 0)
newMainLogoCenterXConstraint.identifier = "mainLogoCenterXConstraint"
newMainLogoCenterXConstraint.isActive = true

let newMainLogoCenterYConstraint = NSLayoutConstraint(
            item: self.mainLogoImageView,
            attribute: .centerY,
            relatedBy: .equal,
            toItem: self.view,
            attribute: .centerY,
            multiplier: 1.0,
            constant: 0)
newMainLogoCenterYConstraint.identifier = "mainLogoCenterYConstraint"
newMainLogoCenterYConstraint.isActive = true

self.view.setNeedsLayout()

UIView.animate(withDuration: 1.1, delay: 0.5, usingSpringWithDamping:  0.4, initialSpringVelocity: 0.0, animations: {

    self.view.layoutIfNeeded()

}, completion: nil)

您在创建将
self.mainlogimageview.centerX
与
self.view.centerY
关联的第一个约束时出错-将第二个约束更改为
self.view.centerX
。不能将x轴定位绑定到y轴定位

此外，请确保正确设置动画，检查我关于如何使用autolayout进行设置的答案

就你而言：

// remove the initial constraint
self.mainLogoCenterXConstraint.isActive = false
self.mainLogoCenterYConstraint.isActive = false

// create new constraint
let newMainLogoCenterXConstraint = NSLayoutConstraint(
            item: self.mainLogoImageView,
            attribute: .centerX,
            relatedBy: .equal,
            toItem: self.view,
            attribute: .centerX,
            multiplier: 1.0,
            constant: 0)
newMainLogoCenterXConstraint.identifier = "mainLogoCenterXConstraint"
newMainLogoCenterXConstraint.isActive = true

let newMainLogoCenterYConstraint = NSLayoutConstraint(
            item: self.mainLogoImageView,
            attribute: .centerY,
            relatedBy: .equal,
            toItem: self.view,
            attribute: .centerY,
            multiplier: 1.0,
            constant: 0)
newMainLogoCenterYConstraint.identifier = "mainLogoCenterYConstraint"
newMainLogoCenterYConstraint.isActive = true

self.view.setNeedsLayout()

UIView.animate(withDuration: 1.1, delay: 0.5, usingSpringWithDamping:  0.4, initialSpringVelocity: 0.0, animations: {

    self.view.layoutIfNeeded()

}, completion: nil)

问题就在这里

     // create new constraint
        let newMainLogoCenterXConstraint = NSLayoutConstraint(
            item: self.mainLogoImageView,
            attribute: .centerX,
            relatedBy: .equal,
            toItem: self.view,
            attribute: .centerY,
            multiplier: 1.0,
            constant: 0)

您提供了兼容类型的中心X和y，但两者都应为中心X

此外，这还不足以在视图中心显示图像，因为它是helperView的子视图，所以需要设置

 self.helperView.clipsToBounds = false // if it's true 

问题就在这里

     // create new constraint
        let newMainLogoCenterXConstraint = NSLayoutConstraint(
            item: self.mainLogoImageView,
            attribute: .centerX,
            relatedBy: .equal,
            toItem: self.view,
            attribute: .centerY,
            multiplier: 1.0,
            constant: 0)

您提供了兼容类型的中心X和y，但两者都应为中心X

此外，这还不足以在视图中心显示图像，因为它是helperView的子视图，所以需要设置

 self.helperView.clipsToBounds = false // if it's true 

不要仅为动画更改约束！使用：首先设置偏移，然后设置为
.identity
。不要仅为动画更改约束！使用设置动画：首先设置偏移，然后设置为
.identity
。