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")
}
}
我的做法如下:
class SignInController: UIViewController , UITextFieldDelegate {
@IBOutlet weak var scrollView: UIScrollView!
// outlet declartion
@IBOutlet weak var signInTextView: UITextField!
var kbHeight: CGFloat!
/**
*
* @method viewDidLoad
*
*/
override func viewDidLoad() {
super.viewDidLoad()
self.signInTextView.delegate = self
}// end viewDidLoad
/**
*
* @method viewWillAppear
*
*/
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(animated)
NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("keyboardWillShow:"), name: UIKeyboardWillShowNotification, object: nil)
NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("keyboardWillHide:"), name: UIKeyboardWillHideNotification, object: nil)
}// end viewWillAppear
/**
*
* @method viewDidAppear
*
*/
override func viewDidAppear(animated: Bool) {
super.viewDidAppear(animated)
}// end viewDidAppear
/**
*
* @method viewWillDisappear
*
*/
override func viewWillDisappear(animated: Bool) {
super.viewWillDisappear(animated)
NSNotificationCenter.defaultCenter().removeObserver(self)
}
/**
*
* @method textFieldShouldReturn
* retun the keyboard value
*
*/
// MARK -
func textFieldShouldReturn(textField: UITextField) -> Bool {
signInTextView.resignFirstResponder()
return true;
}// end textFieldShouldReturn
// MARK - keyboardWillShow
func keyboardWillShow(notification: NSNotification) {
if let userInfo = notification.userInfo {
if let keyboardSize = (userInfo[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue() {
kbHeight = keyboardSize.height
self.animateTextField(true)
}
}
}// end keyboardWillShow
// MARK - keyboardWillHide
func keyboardWillHide(notification: NSNotification) {
self.animateTextField(false)
}// end keyboardWillHide
// MARK - animateTextField
func animateTextField(up: Bool) {
var movement = (up ? -kbHeight : kbHeight)
UIView.animateWithDuration(0.3, animations: {
self.view.frame = CGRectOffset(self.view.frame, 0, movement)
})
}// end animateTextField
/**
*
* @method didReceiveMemoryWarning
*
*/
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}// end didReceiveMemoryWarning
}// end SignInController
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)
}
}
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。
这是一个改进版的@JosephLord和@Hlung的回答。
无论你是否有标签栏，它都适用。
并且它可以完美地恢复由键盘移动到原始位置的视图。
// 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()
// Receive(Get) Notification
NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardNotification:", name: UIKeyboardWillShowNotification, object: nil)
NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardNotification:", name: UIKeyboardWillHideNotification, object: nil)
self.originalConstraint = self.keyboardHeightLayoutConstraint?.constant //for original coordinate.
}
func keyboardNotification(notification: NSNotification) {
let isShowing = notification.name == UIKeyboardWillShowNotification
var tabbarHeight: CGFloat = 0
if self.tabBarController? != nil {
tabbarHeight = self.tabBarController!.tabBar.frame.height
}
if let userInfo = notification.userInfo {
let endFrame = (userInfo[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.CGRectValue()
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.keyboardHeightLayoutConstraint?.constant = isShowing ? (endFrame!.size.height - tabbarHeight) : self.originalConstraint!
UIView.animateWithDuration(duration,
delay: NSTimeInterval(0),
options: animationCurve,
animations: { self.view.layoutIfNeeded() },
completion: nil)
}
}
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)
}
}
