我使用Swift与iOS编程,我使用这段代码来移动UITextField,但它不起作用。我正确地调用了函数keyboardWillShow,但是文本字段没有移动。我正在使用自动布局。
override func viewDidLoad() {
super.viewDidLoad()
NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("keyboardWillShow:"), name:UIKeyboardWillShowNotification, object: nil);
NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("keyboardWillHide:"), name:UIKeyboardWillHideNotification, object: nil);
}
deinit {
NSNotificationCenter.defaultCenter().removeObserver(self);
}
func keyboardWillShow(notification: NSNotification) {
if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue() {
//let contentInsets = UIEdgeInsets(top: 0, left: 0, bottom: keyboardSize.height, right: 0)
var frame = self.ChatField.frame
frame.origin.y = frame.origin.y - keyboardSize.height + 167
self.chatField.frame = frame
println("asdasd")
}
}
我喜欢简洁的Swift代码。这是我能想出的最严格的代码,可以用键盘上下移动文本视图。它目前正在iOS8/9 Swift 2生产应用程序中运行。
更新(2016年3月):
我只是尽可能地压缩了之前的代码。此外,这里还有一些流行的答案,它们硬编码了键盘高度和动画参数。这是没有必要的,更不用说这些答案中的数字并不总是与我在6s+ iOS9上看到的实际值一致(键盘高度226,持续时间0.25,动画曲线7)。在任何情况下,几乎不需要额外的代码来直接从系统获取这些值。见下文。
override func viewDidLoad() {
super.viewDidLoad()
NSNotificationCenter.defaultCenter().addObserver(self, selector: "animateWithKeyboard:", name: UIKeyboardWillShowNotification, object: nil)
NSNotificationCenter.defaultCenter().addObserver(self, selector: "animateWithKeyboard:", name: UIKeyboardWillHideNotification, object: nil)
}
func animateWithKeyboard(notification: NSNotification) {
// Based on both Apple's docs and personal experience,
// I assume userInfo and its documented keys are available.
// If you'd like, you can remove the forced unwrapping and add your own default values.
let userInfo = notification.userInfo!
let keyboardHeight = (userInfo[UIKeyboardFrameEndUserInfoKey] as! NSValue).CGRectValue().height
let duration = userInfo[UIKeyboardAnimationDurationUserInfoKey] as! Double
let curve = userInfo[UIKeyboardAnimationCurveUserInfoKey] as! UInt
let moveUp = (notification.name == UIKeyboardWillShowNotification)
// baseContraint is your Auto Layout constraint that pins the
// text view to the bottom of the superview.
baseConstraint.constant = moveUp ? -keyboardHeight : 0
let options = UIViewAnimationOptions(rawValue: curve << 16)
UIView.animateWithDuration(duration, delay: 0, options: options,
animations: {
self.view.layoutIfNeeded()
},
completion: nil
)
}
注意:这段代码涵盖了大多数注释/一般情况。然而,处理不同的方向和/或自定义键盘可能需要更多的代码。如果你需要处理每一个场景,这可能会有所帮助。
管理键盘的完整代码。
override func viewWillAppear(_ animated: Bool) {
NotificationCenter.default.addObserver(self, selector: #selector(StoryMediaVC.keyboardWillShow), name: UIResponder.keyboardWillShowNotification, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(StoryMediaVC.keyboardWillHide), name: UIResponder.keyboardWillHideNotification, object: nil)
}
override func viewWillDisappear(_ animated: Bool) {
NotificationCenter.default.removeObserver(self, name: UIResponder.keyboardWillShowNotification, object: nil)
NotificationCenter.default.removeObserver(self, name: UIResponder.keyboardWillHideNotification, object: nil)
}
@objc func keyboardWillShow(notification: NSNotification) {
guard let userInfo = notification.userInfo else {return}
guard let keyboardSize = userInfo[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue else {return}
let keyboardFrame = keyboardSize.cgRectValue
if self.view.bounds.origin.y == 0{
self.view.bounds.origin.y += keyboardFrame.height
}
}
@objc func keyboardWillHide(notification: NSNotification) {
if self.view.bounds.origin.y != 0 {
self.view.bounds.origin.y = 0
}
}
另一个解决方案,不依赖于自动布局,约束或任何出口。您所需要的是滚动视图中的字段。
override func viewDidLoad() {
super.viewDidLoad()
NSNotificationCenter.defaultCenter().addObserver(self, selector: "makeSpaceForKeyboard:", name: UIKeyboardWillShowNotification, object: nil)
NSNotificationCenter.defaultCenter().addObserver(self, selector: "makeSpaceForKeyboard:", name: UIKeyboardWillHideNotification, object: nil)
}
func makeSpaceForKeyboard(notification: NSNotification) {
let info = notification.userInfo!
let keyboardHeight:CGFloat = (info[UIKeyboardFrameEndUserInfoKey] as! NSValue).CGRectValue().size.height
let duration:Double = info[UIKeyboardAnimationDurationUserInfoKey] as! Double
if notification.name == UIKeyboardWillShowNotification {
UIView.animateWithDuration(duration, animations: { () -> Void in
var frame = self.view.frame
frame.size.height = frame.size.height - keyboardHeight
self.view.frame = frame
})
} else {
UIView.animateWithDuration(duration, animations: { () -> Void in
var frame = self.view.frame
frame.size.height = frame.size.height + keyboardHeight
self.view.frame = frame
})
}
}
如果你正在使用自动布局,我假设你已经设置了底部空间为Superview约束。如果是这种情况,您只需更新约束的值。这是你如何用一点动画来做到这一点。
func keyboardWasShown(notification: NSNotification) {
let info = notification.userInfo!
let keyboardFrame: CGRect = (info[UIKeyboardFrameEndUserInfoKey] as! NSValue).CGRectValue()
UIView.animateWithDuration(0.1, animations: { () -> Void in
self.bottomConstraint.constant = keyboardFrame.size.height + 20
})
}
添加硬编码的20只是为了将文本框弹出到键盘上方一点。否则键盘的上边距和文本框的下边距将会接触。
当键盘关闭时,将约束的值重置为原始值。