我正在以编程方式创建UIView,然后我将使用约束从下到上为该视图设置动画。但是动画不会显示在该视图对象上。
overlay!.addSubview(contentView)
contentView.translatesAutoresizingMaskIntoConstraints = false
contentView.leadingAnchor.constraint(equalTo: vc.view.leadingAnchor, constant: 20).isActive = true
contentView.trailingAnchor.constraint(equalTo: vc.view.trailingAnchor, constant: -20).isActive = true
contentView.addSubview(messageLabel)
messageLabel.leadingAnchor.constraint(equalTo: contentView.leadingAnchor, constant: 8).isActive = true
messageLabel.trailingAnchor.constraint(equalTo: contentView.trailingAnchor, constant: -8).isActive = true
messageLabel.topAnchor.constraint(equalTo: contentView.topAnchor, constant: 8).isActive = true
messageLabel.bottomAnchor.constraint(equalTo: contentView.bottomAnchor, constant: -8).isActive = true
let width: CGFloat = vc.view.frame.width - 40 - 16
stringHeight = calculateEstimatedHeight(width: width, text: text) + 16
contentView.heightAnchor.constraint(equalToConstant: stringHeight).isActive = true
bottomConstraint = contentView.bottomAnchor.constraint(equalTo: vc.view.bottomAnchor, constant: stringHeight)
bottomConstraint.isActive = true
DispatchQueue.main.asyncAfter(deadline: .now() + 1.5) {
self.showToastViewWithAnimation(viewController: vc)
}
@objc func showToastViewWithAnimation(viewController: Any) {
if let vc = viewController as? ViewController {
vc.view.layoutIfNeeded()
UIView.animate(withDuration: 0.8) {
self.bottomConstraint.constant = -20
vc.view.layoutIfNeeded()
}
}
}
答案 0 :(得分:0)
我已经通过注释指出了一些东西,阅读注释,您将了解代码中的问题,请检查下面的代码。
=>您的代码:overlay!.addSubview(contentView)
@objc func showToastViewWithAnimation(viewController: Any) {
if let vc = viewController as? ViewController {
//vc.view.layoutIfNeeded() - this is not required before updating constraint value
self.bottomConstraint.constant = -20 //update contstraint outside of the animation block
UIView.animate(withDuration: 0.8) {
//vc.view.layoutIfNeeded()
self.overlay?.layoutIfNeeded() //you needs to layout the overlay view, as your other toast views are added in overlay view and not in view of viewcontroller as per your code
}
}
}
答案 1 :(得分:0)
在您的代码中添加以下行:
globals()
,然后在ShowToastView函数中首先找到哪个是底部约束,然后尝试像这样进行更新(记住其提示代码,您可以根据需要对其进行更新):
self.translatesAutoresizingMaskIntoConstraints = false
contentView.translatesAutoresizingMaskIntoConstraints = false