使用Swift使用键盘移动视图
使用Swift使用键盘移动视图
提问于 2014-09-27 08:53:45
我有一个应用程序，在视图的下半部分有一个文本字段。这意味着，当我在文本字段中键入内容时，键盘会覆盖文本字段。
如何在键入时向上移动视图，以便可以看到正在键入的内容，然后在键盘消失时将其移回原来的位置？
我已经到处找过了，但是所有的解决方案似乎都在Obj-C中，我现在还不能完全转换。
任何帮助都将不胜感激。
回答 23
Stack Overflow用户
回答已采纳
发布于 2015-06-30 04:09:28
这里有一个解决方案，不需要处理从一个textField到另一个的切换：
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)
}
func keyboardWillShow(notification: NSNotification) {
if let keyboardSize = (notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.CGRectValue() {
self.view.frame.origin.y -= keyboardSize.height
}
}
func keyboardWillHide(notification: NSNotification) {
self.view.frame.origin.y = 0
}要解决此问题，请将两个函数keyboardWillShow/Hide替换为以下内容：
func keyboardWillShow(notification: NSNotification) {
if let keyboardSize = (notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.CGRectValue() {
if view.frame.origin.y == 0 {
self.view.frame.origin.y -= keyboardSize.height
}
}
}
func keyboardWillHide(notification: NSNotification) {
if view.frame.origin.y != 0 {
self.view.frame.origin.y = 0
}
}Swift 3.0：
override func viewDidLoad() {
super.viewDidLoad()
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)
}
@objc func keyboardWillShow(notification: NSNotification) {
if let keyboardSize = (notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {
if self.view.frame.origin.y == 0 {
self.view.frame.origin.y -= keyboardSize.height
}
}
}
@objc func keyboardWillHide(notification: NSNotification) {
if self.view.frame.origin.y != 0 {
self.view.frame.origin.y = 0
}
}Swift 4.0：
override func viewDidLoad() {
super.viewDidLoad()
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)
}
@objc func keyboardWillShow(notification: NSNotification) {
if let keyboardSize = (notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {
if self.view.frame.origin.y == 0 {
self.view.frame.origin.y -= keyboardSize.height
}
}
}
@objc func keyboardWillHide(notification: NSNotification) {
if self.view.frame.origin.y != 0 {
self.view.frame.origin.y = 0
}
}Swift 4.2：
override func viewDidLoad() {
super.viewDidLoad()
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow), name: UIResponder.keyboardWillShowNotification, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide), name: UIResponder.keyboardWillHideNotification, object: nil)
}
@objc func keyboardWillShow(notification: NSNotification) {
if let keyboardSize = (notification.userInfo?[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {
if self.view.frame.origin.y == 0 {
self.view.frame.origin.y -= keyboardSize.height
}
}
}
@objc func keyboardWillHide(notification: NSNotification) {
if self.view.frame.origin.y != 0 {
self.view.frame.origin.y = 0
}
}Stack Overflow用户
发布于 2014-09-27 18:37:12
将此代码添加到视图控制器中。就像一种护身符。只需调整这些值即可。
override func viewDidLoad() {
super.viewDidLoad()
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow), name:NSNotification.Name.UIKeyboardWillShow, object: nil);
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide), name:NSNotification.Name.UIKeyboardWillHide, object: nil);
}
@objc func keyboardWillShow(sender: NSNotification) {
self.view.frame.origin.y -= 150
}
@objc func keyboardWillHide(sender: NSNotification) {
self.view.frame.origin.y += 150
}Stack Overflow用户
发布于 2016-01-06 23:57:37
我看到所有答案都是通过键盘高度的值来移动视图本身的。好吧，我有一个详细的答案，如果你使用约束，也就是autolayout，它可以通过改变约束的值(例如底部或顶部约束)来移动视图，或者你可以使用键盘大小值。
在本例中，我使用了从文本字段到底部布局视图的底部约束，初始值为175。
@IBOutlet weak var bottomConstraint: NSLayoutConstraint!
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);
}
func keyboardWillShow(notification: NSNotification) {
//To retrieve keyboard size, uncomment following line
//let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue()
bottomConstraint.constant = 260
UIView.animateWithDuration(0.3) {
self.view.layoutIfNeeded()
}
}
func keyboardWillHide(notification: NSNotification) {
//To retrieve keyboard size, uncomment following line
//let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue()
bottomConstraint.constant = 175
UIView.animateWithDuration(0.3) {
self.view.layoutIfNeeded()
}
}页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/26070242
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