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
我看到所有的答案都是通过键盘高度的值移动视图本身。好吧，我有一个详细的答案，这可能是有用的，如果你正在使用约束即自动布局，移动一个视图通过改变其约束值(底部或顶部约束为例)由一个预定义的值或你可以使用键盘大小值。
在这个例子中，我使用底部约束从文本字段到底部布局视图的初始值为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()
}
}
其他回答
验证的答案没有考虑到文本字段的位置，并有一些错误(双位移，永远不会回到主位置，位移即使文本字段是在视图的顶部…)
这个想法是:
获取焦点TextField的Y的绝对位置 来获取键盘高度 来获取屏幕高度 然后计算键盘位置和文本框之间的距离(如果< 0 ->向上移动视图) 使用UIView。而不是UIView.frame.origin.y -= ..，因为用UIView更容易回到原来的位置。变换= .identity
然后，我们将能够移动视图，只有在必要和特定的位移，以便有聚焦texField刚刚超过键盘
代码如下:
斯威夫特4
class ViewController: UIViewController, UITextFieldDelegate {
var textFieldRealYPosition: CGFloat = 0.0
override func viewDidLoad() {
super.viewDidLoad()
NotificationCenter.default.addObserver(self, selector: #selector(VehiculeViewController.keyboardWillShow), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(VehiculeViewController.keyboardWillHide), name: NSNotification.Name.UIKeyboardWillHide, object: nil)
// Delegate all textfields
}
@objc func keyboardWillShow(notification: NSNotification) {
if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
let distanceBetweenTextfielAndKeyboard = self.view.frame.height - textFieldRealYPosition - keyboardSize.height
if distanceBetweenTextfielAndKeyboard < 0 {
UIView.animate(withDuration: 0.4) {
self.view.transform = CGAffineTransform(translationX: 0.0, y: distanceBetweenTextfielAndKeyboard)
}
}
}
}
@objc func keyboardWillHide(notification: NSNotification) {
UIView.animate(withDuration: 0.4) {
self.view.transform = .identity
}
}
func textFieldDidBeginEditing(_ textField: UITextField) {
textFieldRealYPosition = textField.frame.origin.y + textField.frame.height
//take in account all superviews from textfield and potential contentOffset if you are using tableview to calculate the real position
}
}
这是我的解决方案(实际上这段代码是在你的视图中有几个文本字段的情况下，这也适用于当你有一个文本字段的情况下)
class MyViewController: UIViewController, UITextFieldDelegate {
@IBOutlet weak var firstTextField: UITextField!
@IBOutlet weak var secondTextField: UITextField!
var activeTextField: UITextField!
var viewWasMoved: Bool = false
override func viewDidLoad() {
super.viewDidLoad()
NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(PrintViewController.keyboardWillShow(_:)), name: UIKeyboardWillShowNotification, object: nil)
NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(PrintViewController.keyboardWillHide(_:)), name: UIKeyboardWillHideNotification, object: nil)
}
override func viewDidDisappear(animated: Bool) {
super.viewWillDisappear(animated)
NSNotificationCenter.defaultCenter().removeObserver(self)
}
func textFieldDidBeginEditing(textField: UITextField) {
self.activeTextField = textField
}
func textFieldDidEndEditing(textField: UITextField) {
self.activeTextField = nil
}
func textFieldShouldReturn(textField: UITextField) -> Bool {
textField.resignFirstResponder()
return true
}
func keyboardWillShow(notification: NSNotification) {
let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue()
var aRect: CGRect = self.view.frame
aRect.size.height -= keyboardSize!.height
let activeTextFieldRect: CGRect? = activeTextField?.frame
let activeTextFieldOrigin: CGPoint? = activeTextFieldRect?.origin
if (!CGRectContainsPoint(aRect, activeTextFieldOrigin!)) {
self.viewWasMoved = true
self.view.frame.origin.y -= keyboardSize!.height
} else {
self.viewWasMoved = false
}
}
func keyboardWillHide(notification: NSNotification) {
if (self.viewWasMoved) {
if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue() {
self.view.frame.origin.y += keyboardSize.height
}
}
}
这是一个解决方案，不处理从一个textField到另一个切换:
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
}
要解决这个问题，将keyboardWillShow/Hide替换为以下两个函数:
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
}
}
斯威夫特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
}
}
斯威夫特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
}
}
斯威夫特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
}
}
当打开键盘时，它100%完美地回答了所有人的更新表视图高度
对于Swift4.2
override func viewDidLoad() {
super.viewDidLoad()
NotificationCenter.default.addObserver(self, selector: #selector(RecipeVC.keyboardWillShow), name: UIResponder.keyboardWillShowNotification, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(RecipeVC.keyboardWillHide), name: UIResponder.keyboardWillHideNotification, object: nil)
}
@objc func keyboardWillShow(notification: NSNotification) {
if ((notification.userInfo?[UIResponder.keyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue) != nil {
var userInfo = notification.userInfo!
var keyboardFrame:CGRect = (userInfo[UIResponder.keyboardFrameEndUserInfoKey] as! NSValue).cgRectValue
keyboardFrame = self.view.convert(keyboardFrame, from: nil)
var contentInset:UIEdgeInsets = self.tbl.contentInset
contentInset.bottom = keyboardFrame.size.height
self.tbl.contentInset = contentInset
}
}
@objc func keyboardWillHide(notification: NSNotification) {
if ((notification.userInfo?[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue) != nil {
let contentInset:UIEdgeInsets = UIEdgeInsets(top: 0, left: 0, bottom: 0, right: 0)
self.tbl.contentInset = contentInset
}
}
Swift3.2
override func viewDidLoad() {
super.viewDidLoad()
NotificationCenter.default.addObserver(self, selector: #selector(RecipeVC.keyboardWillShow), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(RecipeVC.keyboardWillHide), name: NSNotification.Name.UIKeyboardWillHide, object: nil)
}
func keyboardWillShow(notification: NSNotification) {
if ((notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue) != nil {
//self.view.frame.origin.y -= keyboardSize.height
var userInfo = notification.userInfo!
var keyboardFrame:CGRect = (userInfo[UIKeyboardFrameEndUserInfoKey] as! NSValue).cgRectValue
keyboardFrame = self.view.convert(keyboardFrame, from: nil)
var contentInset:UIEdgeInsets = self.tbl.contentInset
contentInset.bottom = keyboardFrame.size.height
self.tbl.contentInset = contentInset
}
}
func keyboardWillHide(notification: NSNotification) {
if ((notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue) != nil {
let contentInset:UIEdgeInsets = UIEdgeInsets(top: 0, left: 0, bottom: 0, right: 0)
self.tbl.contentInset = contentInset
}
}
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
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