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")
}
}
下面是一个简单的解决方案,其中文本字段有一个约束将其绑定到底部布局指南。它只是将键盘高度添加到约束常数中。
// This constraint ties the text field to the bottom layout guide
@IBOutlet var textFieldToBottomLayoutGuideConstraint: NSLayoutConstraint!
override func viewDidLoad() {
super.viewDidLoad()
NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWillShow:", name:UIKeyboardWillShowNotification, object: nil);
NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWillHide:", name:UIKeyboardWillHideNotification, object: nil);
}
func keyboardWillShow(sender: NSNotification) {
if let keyboardSize = (sender.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue() {
self.textFieldToBottomLayoutGuideConstraint?.constant += keyboardSize.height
}
}
func keyboardWillHide(sender: NSNotification) {
if let keyboardSize = (sender.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue() {
self.textFieldToBottomLayoutGuideConstraint?.constant -= keyboardSize.height
}
}
斯威夫特4。x答案,合并来自@Joseph Lord和@Isuru的答案。bottomConstraint表示你想移动的视图的底部约束。
override func viewDidLoad() {
// Call super
super.viewDidLoad()
// Subscribe to keyboard notifications
NotificationCenter.default.addObserver(self,
selector: #selector(keyboardNotification(notification:)),
name: UIResponder.keyboardWillChangeFrameNotification,
object: nil)
}
deinit {
NotificationCenter.default.removeObserver(self)
}
@objc func keyboardNotification(notification: NSNotification) {
if let userInfo = notification.userInfo {
// Get keyboard frame
let keyboardFrame = (userInfo[UIResponder.keyboardFrameEndUserInfoKey] as! NSValue).cgRectValue
// Set new bottom constraint constant
let bottomConstraintConstant = keyboardFrame.origin.y >= UIScreen.main.bounds.size.height ? 0.0 : keyboardFrame.size.height
// Set animation properties
let duration = (userInfo[UIResponder.keyboardAnimationDurationUserInfoKey] as? NSNumber)?.doubleValue ?? 0
let animationCurveRawNSN = userInfo[UIResponder.keyboardAnimationCurveUserInfoKey] as? NSNumber
let animationCurveRaw = animationCurveRawNSN?.uintValue ?? UIView.AnimationOptions.curveEaseInOut.rawValue
let animationCurve = UIView.AnimationOptions(rawValue: animationCurveRaw)
// Animate the view you care about
UIView.animate(withDuration: duration, delay: 0, options: animationCurve, animations: {
self.bottomConstraint.constant = bottomConstraintConstant
self.view.layoutIfNeeded()
}, completion: nil)
}
}
编辑:我推荐一个更简单、更干净的解决方案。只需将底部间距约束的类更改为KeyboardLayoutConstraint。它会自动展开到键盘高度。
这是一个改进版的@JosephLord的回答。
在iOS 8.3 iPad模拟器上测试,Portrait。Xcode6.3 beta4,我发现他的答案不工作时,键盘隐藏,因为UIKeyboardFrameEndUserInfoKey是“NSRect:{{0, 1024},{768, 264}}”;高度不为0。
这回到使用传统的UIKeyboardWillShowNotification和UIKeyboardWillHideNotification来更好地判断键盘何时隐藏,而不是依赖于结束帧的高度。UIKeyboardWillShowNotification也会在键盘帧改变时发送,所以它应该覆盖所有的用例。
// You have to set this up in storyboard first!.
// It's a vertical spacing constraint between view and bottom of superview.
@IBOutlet weak var bottomSpacingConstraint: NSLayoutConstraint!
override func viewDidLoad() {
super.viewDidLoad()
NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("keyboardNotification:"), name:UIKeyboardWillShowNotification, object: nil);
NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("keyboardNotification:"), name:UIKeyboardWillHideNotification, object: nil);
}
deinit {
NSNotificationCenter.defaultCenter().removeObserver(self)
}
func keyboardNotification(notification: NSNotification) {
let isShowing = notification.name == UIKeyboardWillShowNotification
if let userInfo = notification.userInfo {
let endFrame = (userInfo[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.CGRectValue()
let endFrameHeight = endFrame?.size.height ?? 0.0
let duration:NSTimeInterval = (userInfo[UIKeyboardAnimationDurationUserInfoKey] as? NSNumber)?.doubleValue ?? 0
let animationCurveRawNSN = userInfo[UIKeyboardAnimationCurveUserInfoKey] as? NSNumber
let animationCurveRaw = animationCurveRawNSN?.unsignedLongValue ?? UIViewAnimationOptions.CurveEaseInOut.rawValue
let animationCurve:UIViewAnimationOptions = UIViewAnimationOptions(rawValue: animationCurveRaw)
self.bottomSpacingConstraint?.constant = isShowing ? endFrameHeight : 0.0
UIView.animateWithDuration(duration,
delay: NSTimeInterval(0),
options: animationCurve,
animations: { self.view.layoutIfNeeded() },
completion: nil)
}
}
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。
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
NotificationCenter.default.addObserver(self, selector: #selector(ViewController.keyboardWillShow), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(ViewController.keyboardWillHide), name: NSNotification.Name.UIKeyboardWillHide, object: nil)
}
func keyboardWillShow(_ notification:Notification) {
if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
tableView.contentInset = UIEdgeInsetsMake(0, 0, keyboardSize.height, 0)
}
}
func keyboardWillHide(_ notification:Notification) {
if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
tableView.contentInset = UIEdgeInsetsMake(0, 0, 0, 0)
}
}