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
类似于@Boris的回答，但在Swift 5中:
override func 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)
}
@IBAction func keyboardWillShow(notification: NSNotification) {
if let keyboardSize = (notification.userInfo?[UIResponder.keyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
if self.view.frame.origin.y == 0 {
self.view.frame.origin.y -= keyboardSize.height
}
}
}
@IBAction func keyboardWillHide(notification: NSNotification) {
if self.view.frame.origin.y != 0 {
self.view.frame.origin.y = 0
}
}
其他回答
Swift 3
func textFieldDidBeginEditing(_ textField: UITextField) { // became first responder
//move textfields up
let myScreenRect: CGRect = UIScreen.main.bounds
let keyboardHeight : CGFloat = 216
UIView.beginAnimations( "animateView", context: nil)
var movementDuration:TimeInterval = 0.35
var needToMove: CGFloat = 0
var frame : CGRect = self.view.frame
if (textField.frame.origin.y + textField.frame.size.height + UIApplication.shared.statusBarFrame.size.height > (myScreenRect.size.height - keyboardHeight - 30)) {
needToMove = (textField.frame.origin.y + textField.frame.size.height + UIApplication.shared.statusBarFrame.size.height) - (myScreenRect.size.height - keyboardHeight - 30);
}
frame.origin.y = -needToMove
self.view.frame = frame
UIView.commitAnimations()
}
func textFieldDidEndEditing(_ textField: UITextField) {
//move textfields back down
UIView.beginAnimations( "animateView", context: nil)
var movementDuration:TimeInterval = 0.35
var frame : CGRect = self.view.frame
frame.origin.y = 0
self.view.frame = frame
UIView.commitAnimations()
}
如果你在同一个VC中有2个或更多的文本字段，用户点击其中一个，然后点击另一个，不调用keyboardWillHide函数，视图会再向上一次，这是不必要的，因为你会有键盘，一个空格，它有键盘的高度，然后视图，使用我编辑的答案中的代码:
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?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue() {
self.view.frame.origin.y -= keyboardSize.height
}
}
func keyboardWillHide(notification: NSNotification) {
if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue() {
self.view.frame.origin.y += keyboardSize.height
}
}
为了解决这个问题，将两个函数"KeyboardWillShow/Hide"替换为:
func keyboardWillShow(notification: NSNotification) {
if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue() {
if view.frame.origin.y == 0{
self.view.frame.origin.y -= keyboardSize.height
}
}
}
func keyboardWillHide(notification: NSNotification) {
if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue() {
if view.frame.origin.y != 0 {
self.view.frame.origin.y += keyboardSize.height
}
}
}
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
}
}
}
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
}
}
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)
推荐文章
- 如何删除默认的导航栏空间在SwiftUI导航视图
- 如何在iOS中使用Swift编程segue
- Swift -整数转换为小时/分钟/秒
- 如何舍入一个双到最近的Int在迅速?
- 扁平化数组的数组在Swift
- Swift:声明一个空字典
- 在成功提交我的应用程序后，“太多符号文件”
- 从数组中随机选择一个元素
- 首先添加一个UIView，甚至是导航栏
- 我如何改变UIButton标题颜色?
- 在Swift中如何调用GCD主线程上的参数方法?
- NSLayoutConstraints是可动画的吗?
- iOS -构建失败，CocoaPods无法找到头文件
- CFNetwork SSLHandshake iOS 9失败
- swift语言中的结构与类
