我有一个应用,它在视图的下半部分有一个文本框。 这意味着当我在文本框中输入时,键盘会覆盖文本框。
我如何在打字时向上移动视图,这样我就可以看到我键入的内容,然后在键盘消失时将它移回原来的位置?
我到处都看了,但所有的解似乎都在Obj-C中,我还不能完全转换。
任何帮助都将不胜感激。
我有一个应用,它在视图的下半部分有一个文本框。 这意味着当我在文本框中输入时,键盘会覆盖文本框。
我如何在打字时向上移动视图,这样我就可以看到我键入的内容,然后在键盘消失时将它移回原来的位置?
我到处都看了,但所有的解似乎都在Obj-C中,我还不能完全转换。
任何帮助都将不胜感激。
当前回答
swift 3.0插入在viewDidLoad(),这->
{
view addSubview (Your_messageInputConteinerView)。
view.addConstraintWithFormat(format: "H:|[v0]|", views:Your_messageInputConteinerView)
view.addConstraintWithFormat(format: "V:[v0(48)]", views:Your_messageInputConteinerView)
addobserver (self, selector: #selector(handleKeyboardNotification(notification:))), name: NSNotification.Name。对象:nil)
addobserver (self, selector: #selector(handleKeyboardNotification(notification:))),名称:.UIKeyboardWillHide,对象:nil)
bottomConstraint = NSLayoutConstraint(item: Your_messageInputConteinerView, attribute: .bottom, relatedBy: .equal, toItem: view, attribute: .bottom, multiplier: 1, constant: 0)
view.addConstraint(bottomConstraint!)
}
func handleKeyboardNotification(通知:通知){
if let userInfo = notification.userInfo {
if let keyBoardFrame = (userInfo[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue{
print(keyBoardFrame)
if bottomConstraint?.constant != CGFloat(0) {
bottomConstraint?.constant = 0
return
}
bottomConstraint?.constant = -keyBoardFrame.height
or
self.view.frame.origin.y = -keyBoardFrame.height
}
}
}
其他回答
@Boris的解决方案非常好,但观点有时会被破坏。
为了实现完美的对齐,请使用下面的代码
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)}
功能:
@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
}
}}
And,
@objc func keyboardWillHide(notification: NSNotification) {
if let keyboardSize = (notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {
if self.view.frame.origin.y != 0{
self.view.frame.origin.y = 0
}
} }
我注意到其他答案涉及从视图中删除一些顶部。如果你想简单地调整视图的大小而不削减任何内容,只需尝试这个方法:)
func keyboardWillShow(notification: NSNotification) {
if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue() {
self.view.setTranslatesAutoresizingMaskIntoConstraints(true)
self.view.frame = CGRectMake(self.view.frame.origin.x, self.view.frame.origin.y, self.view.frame.size.width, self.view.frame.height - keyboardSize.height)
}
}
func keyboardWillHide(notification: NSNotification) {
if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue() {
self.collectionView.setTranslatesAutoresizingMaskIntoConstraints(false)
self.view.frame = CGRectMake(self.view.frame.origin.x, self.view.frame.origin.y, self.view.frame.size.width, self.view.frame.height + keyboardSize.height)
}
}
斯威夫特5.0:
经过4-5个小时的战斗,我得到了一个简单的扩展UIViewController与简单的代码,就像魅力
*当TextField在键盘上方时,视图不应该移动
*不需要设置常量值为NSLayoutConstraint
*无需第三方库
*无需动画代码
*适用于tableview
*这适用于自动布局/自动调整大小
extension UIViewController {
func addKeyboardObserver() {
NotificationCenter.default.addObserver(self, selector: #selector(keyboardNotifications(notification:)),
name: UIResponder.keyboardWillChangeFrameNotification,
object: nil)
}
func removeKeyboardObserver(){
NotificationCenter.default.removeObserver(self, name: UIResponder.keyboardWillChangeFrameNotification, object: nil)
}
// This method will notify when keyboard appears/ dissapears
@objc func keyboardNotifications(notification: NSNotification) {
var txtFieldY : CGFloat = 0.0 //Using this we will calculate the selected textFields Y Position
let spaceBetweenTxtFieldAndKeyboard : CGFloat = 5.0 //Specify the space between textfield and keyboard
var frame = CGRect(x: 0, y: 0, width: 0, height: 0)
if let activeTextField = UIResponder.currentFirst() as? UITextField ?? UIResponder.currentFirst() as? UITextView {
// Here we will get accurate frame of textField which is selected if there are multiple textfields
frame = self.view.convert(activeTextField.frame, from:activeTextField.superview)
txtFieldY = frame.origin.y + frame.size.height
}
if let userInfo = notification.userInfo {
// here we will get frame of keyBoard (i.e. x, y, width, height)
let keyBoardFrame = (userInfo[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue
let keyBoardFrameY = keyBoardFrame!.origin.y
let keyBoardFrameHeight = keyBoardFrame!.size.height
var viewOriginY: CGFloat = 0.0
//Check keyboards Y position and according to that move view up and down
if keyBoardFrameY >= UIScreen.main.bounds.size.height {
viewOriginY = 0.0
} else {
// if textfields y is greater than keyboards y then only move View to up
if txtFieldY >= keyBoardFrameY {
viewOriginY = (txtFieldY - keyBoardFrameY) + spaceBetweenTxtFieldAndKeyboard
//This condition is just to check viewOriginY should not be greator than keyboard height
// if its more than keyboard height then there will be black space on the top of keyboard.
if viewOriginY > keyBoardFrameHeight { viewOriginY = keyBoardFrameHeight }
}
}
//set the Y position of view
self.view.frame.origin.y = -viewOriginY
}
}
}
添加这个扩展的UIResponder得到哪个TextField被选中
extension UIResponder {
static weak var responder: UIResponder?
static func currentFirst() -> UIResponder? {
responder = nil
UIApplication.shared.sendAction(#selector(trap), to: nil, from: nil, for: nil)
return responder
}
@objc private func trap() {
UIResponder.responder = self
}
}
然后在你的任何ViewController中使用这个
override func viewWillAppear(_ animated: Bool) {
self.addKeyboardObserver()
}
override func viewWillDisappear(_ animated: Bool) {
self.removeKeyboardObserver()
}
在func viewWillAppear中注册这个通知(_ animated: Bool) 在func中注销此通知viewWillDisappear(_ animated:Bool) 下载演示文件
我们对KeyboardWillHideNotification的定义做了一些改变。
此解决方案适用于Swift 4.2:
NotificationCenter.default.addObserver(self, selector: #selector(ViewController.keyboardWillShow), name: UIResponder.keyboardWillShowNotification, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(ViewController.keyboardWillHide), name: UIResponder.keyboardWillHideNotification, object: nil)
@objc func keyboardWillShow(_ notification:Notification) {
if let keyboardSize = (notification.userInfo?[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {
self.view.frame.origin.y -= keyboardSize.height
}
}
@objc func keyboardWillHide(_ notification:Notification) {
if let keyboardSize = (notification.userInfo?[UIResponder.keyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
self.view.frame.origin.y += keyboardSize.height
}
}
Swift 3更新…
正如其他人所说,你需要在控制器的viewDidLoad()方法中添加通知观察者,如下所示:
NotificationCenter.default.addObserver(forName: .UIKeyboardWillShow, object: nil, queue: nil)
{ notification in
self.keyboardWillShow(notification)
}
NotificationCenter.default.addObserver(forName: .UIKeyboardWillHide, object: nil, queue: nil)
{ notification in
self.keyboardWillHide(notification)
}
NotificationCenter.default.addObserver(forName: .UIKeyboardDidShow, object: nil, queue: nil)
{ _ in
self.enableUserInteraction()
}
NotificationCenter.default.addObserver(forName: .UIKeyboardDidHide, object: nil, queue: nil)
{ _ in
self.enableUserInteraction()
}
记得在适当的地方删除你的观察器(我在viewWillDisappear()方法中这样做)
NotificationCenter.default.removeObserver(self, name: .UIKeyboardWillShow, object: nil)
NotificationCenter.default.removeObserver(self, name: .UIKeyboardWillHide, object: nil)
NotificationCenter.default.removeObserver(self, name: .UIKeyboardDidShow, object: nil)
NotificationCenter.default.removeObserver(self, name: .UIKeyboardDidHide, object: nil)
然后,实现你的show和hide方法——注意告诉应用程序忽略交互事件的行(beginIgnoringInteractionEvents)。这很重要,因为如果没有它,用户可能会点击一个字段甚至滚动视图,导致第二次发生移位,从而导致可怕的UI故障。在键盘显示和隐藏之前忽略交互事件将防止这种情况:
func keyboardWillShow(notification: Notification)
{
if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue
{
UIApplication.shared.beginIgnoringInteractionEvents()
self.view.frame.origin.y -= keyboardSize.height
// add this line if you are shifting a scrollView, as in a chat application
self.timelineCollectionView.contentInset.top += keyboardSize.height
}
}
func keyboardWillHide(notification: Notification)
{
if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue
{
UIApplication.shared.beginIgnoringInteractionEvents()
self.view.frame.origin.y += keyboardSize.height
// add this line if you are shifting a scrollView, as in a chat application
self.timelineCollectionView.contentInset.top -= keyboardSize.height
}
}
最后,重新启用用户交互(记住,这个方法在键盘didShow或didHide之后触发):
func enableUserInteraction()
{
UIApplication.shared.endIgnoringInteractionEvents()
}