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
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
其他回答
这个视频教程是最好的。7分钟长,会很有意义。这样一个简单的解决方案,当你有多个文本字段,并希望滚动视图移动“x”数量的像素时,特定的文本字段被点击。
https://youtu.be/VuiPGJOEBH4
就这些步骤:
-把你所有的文本字段放在一个滚动视图中,约束到视图的边缘。
-连接所有的文本字段和滚动视图作为视图控制器的委托。
-用IBOutlet连接所有文本字段和滚动视图。
class ViewController: UIViewController, UITextFieldDelegate {
添加UITextFieldDelegate协议到你的类中
@IBOutlet var stateAddress: UITextField!
@IBOutlet var zipAddress: UITextField!
@IBOutlet var phoneNumber: UITextField!
@IBOutlet var vetEmailAddress: UITextField!
@IBOutlet weak var scrollView: UIScrollView!
-在swift文件中添加UITextFieldDelegate方法:
func textFieldShouldReturn(textField: UITextField) -> Bool {
textField.resignFirstResponder()
return true
}
func textFieldDidBeginEditing(textField: UITextField) {
if (textField == self.stateAddress) {
scrollView.setContentOffset(CGPointMake(0, 25), animated: true)
}
else if (textField == self.zipAddress) {
scrollView.setContentOffset(CGPointMake(0, 57), animated: true)
}
else if (textField == self.phoneNumber) {
scrollView.setContentOffset(CGPointMake(0, 112), animated: true)
}
else if (textField == self.vetEmailAddress) {
scrollView.setContentOffset(CGPointMake(0, 142), animated: true)
}
}
func textFieldDidEndEditing(textField: UITextField) {
scrollView.setContentOffset(CGPointMake(0, 0), animated: true)
}
第一种方法只是激活键盘上的返回按钮来关闭键盘。第二个是当你点击到任何特定的文本域,然后设置你的滚动视图滚动的距离的y偏移(我的是基于我的视图控制器上的y位置25,57,112,142)。最后一个说,当你从键盘上点击时,滚动视图会回到原来的位置。
我使我的视图像素完美的这种方式!
由于在Combine中没有如何做到这一点的答案,这里是我使用的方法。
我们创建一个发布者来监听通知,显示和隐藏。 为了显示,我们从通知userInfo中获取键盘帧,并检查当前活动响应器是否包含在其中。如果被覆盖,返回键盘帧高度。如果它没有被覆盖,返回0,我们不想移动帧。对于隐藏通知,我们简单地返回0。
private var keyboardHeightPublisher: AnyPublisher<CGFloat, Never> {
Publishers.Merge(
NotificationCenter.default
.publisher(for: UIResponder.keyboardWillShowNotification)
.compactMap { $0.userInfo?[UIResponder.keyboardFrameEndUserInfoKey] as? CGRect }
.map { $0.intersects(self.view.firstResponder!.frame) ? $0.height : 0 }
.map { $0 * -1 },
NotificationCenter.default
.publisher(for: UIResponder.keyboardWillHideNotification)
.map { _ in CGFloat(0) }
).eraseToAnyPublisher()
}
在viewDidLoad中,我们只需订阅发布者,相应地改变视图框架。
override func viewDidLoad() {
super.viewDidLoad()
keyboardHeightPublisher.sink{ [weak self] height in
self?.view.frame.origin.y = height
}.store(in: &cancelables)
}
编辑 小心!如果firstResponder在子视图中,你必须计算与整个屏幕相对应的帧,以检查它们是否相交。 例子:
let myViewGlobalFrame = myView.convert(myView.frame, to: parentView)
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()
}
对于黑屏错误(Swift 4和4.2)。
我解决了黑屏的问题。在验证方案中,敲击后键盘高度变化,导致黑屏。
必须使用UIKeyboardFrameEndUserInfoKey而不是UIKeyboardFrameBeginUserInfoKey
var isKeyboardAppear = false
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(notification: NSNotification) {
if !isKeyboardAppear {
if let keyboardSize = (notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {
if self.view.frame.origin.y == 0{
self.view.frame.origin.y -= keyboardSize.height
}
}
isKeyboardAppear = true
}
}
@objc func keyboardWillHide(notification: NSNotification) {
if isKeyboardAppear {
if let keyboardSize = (notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {
if self.view.frame.origin.y != 0{
self.view.frame.origin.y += keyboardSize.height
}
}
isKeyboardAppear = false
}
}
将这个添加到你的视图控制器中。效果非常好。只是调整数值。
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
}