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我遇到显示键盘时更改约束的问题。 我目前正在建立一个登录屏幕，我已经设置了约束，以在框架中水平和垂直居中一个具有2个文本框和一个按钮的堆栈视图。徽标（imageview）位于堆栈视图之上，并具有独立的约束。更改键盘动画反弹的故事板约束
当键盘出现时，我想动画的约束来移动stackview和标志了一下，所以键盘不包括任何东西。
键盘在字段上还有一个“下一个”按钮和一个“开始”按钮。
问题我现在有的是，每次按下“下一步”或清除文本框，约束再次改变，从而stackview和徽标“反弹”，这有点烦人。另外，我知道很多人可能会使用scrollview进行提示，但这不是真正的选择。 我也有底部的按钮来创建一个帐户，所以我也不能真正改变整个框架高度。
我猜测，因为它调用“textField.resignFirstResponder（）”，“keyboardWillHide”通知被调用，因此它开始动画。
我在网上到处搜索并尝试了很多东西来解决它，但我现在真的没有想法和动力，所以我希望有人对我在这里可能做错的想法有所了解。 在此先感谢！
class LoginVC: UIViewController, UITextFieldDelegate {
@IBOutlet weak var emailField: SkyFloatingLabelTextFieldWithIcon!
@IBOutlet weak var passwordField: SkyFloatingLabelTextFieldWithIcon!
@IBOutlet weak var signInBtn: TransitionSubmitButton!
@IBOutlet weak var contentCenterConstraint: NSLayoutConstraint!
@IBOutlet weak var logoTopConstraint: NSLayoutConstraint!
@IBOutlet weak var equalWidthConstraint: NSLayoutConstraint!
override func viewDidLoad() {
super.viewDidLoad()
setupKeyboardButtons()
addObservers()
// using extension to hide keyboard when tapped around
self.hideKeyboardWhenTappedAround()
}
func addObservers(){
NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardWillShow(_:)), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardWillHide(_:)), name: NSNotification.Name.UIKeyboardWillChangeFrame, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(goToDifferentView), name: NSNotification.Name(rawValue: "LoginPressed"), object: nil)
}
func keyboardWillShow(_ notification: NSNotification){
// calling layoutIfNeeded because otherwise text in textfield bounces when animating for some reason
view.layoutIfNeeded()
self.contentCenterConstraint.constant = -50
self.equalWidthConstraint.constant = -30
self.logoTopConstraint.constant = -10
UIView.animate(withDuration: 0.5) {
self.view.layoutIfNeeded()
}
}
func keyboardWillHide(_ notification: NSNotification){
view.layoutIfNeeded()
self.contentCenterConstraint.constant = 0
self.equalWidthConstraint.constant = 0
self.logoTopConstraint.constant = 10
UIView.animate(withDuration: 0.5) {
self.view.layoutIfNeeded()
}
}
private func setupKeyboardButtons(){
// textfield delegates instellen, dit dient om keyboard actions te kunnen doen
self.emailField.delegate = self
self.emailField.enablesReturnKeyAutomatically = true
self.passwordField.delegate = self
self.passwordField.enablesReturnKeyAutomatically = true
}
func textFieldShouldReturn(_ textField: UITextField) -> Bool {
textField.resignFirstResponder()
switch(textField) {
case self.emailField:
self.passwordField.becomeFirstResponder()
break
case self.passwordField:
signInBtn.sendActions(for: .touchUpInside)
break
default:
textField.resignFirstResponder()
break
}
return true
}
// remove observers
override func viewWillDisappear(_ animated: Bool) {
NotificationCenter.default.removeObserver(self, name: NSNotification.Name.UIKeyboardWillShow, object: nil)
NotificationCenter.default.removeObserver(self, name: NSNotification.Name.UIKeyboardWillHide, object: nil)
}
}