我使用Swift与iOS编程,我使用这段代码来移动UITextField,但它不起作用。我正确地调用了函数keyboardWillShow,但是文本字段没有移动。我正在使用自动布局。
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);
}
deinit {
NSNotificationCenter.defaultCenter().removeObserver(self);
}
func keyboardWillShow(notification: NSNotification) {
if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue() {
//let contentInsets = UIEdgeInsets(top: 0, left: 0, bottom: keyboardSize.height, right: 0)
var frame = self.ChatField.frame
frame.origin.y = frame.origin.y - keyboardSize.height + 167
self.chatField.frame = frame
println("asdasd")
}
}
我创建了一个Swift 3协议来处理键盘的出现/消失
import UIKit
protocol KeyboardHandler: class {
var bottomConstraint: NSLayoutConstraint! { get set }
func keyboardWillShow(_ notification: Notification)
func keyboardWillHide(_ notification: Notification)
func startObservingKeyboardChanges()
func stopObservingKeyboardChanges()
}
extension KeyboardHandler where Self: UIViewController {
func startObservingKeyboardChanges() {
// NotificationCenter observers
NotificationCenter.default.addObserver(forName: NSNotification.Name.UIKeyboardWillShow, object: nil, queue: nil) { [weak self] notification in
self?.keyboardWillShow(notification)
}
// Deal with rotations
NotificationCenter.default.addObserver(forName: NSNotification.Name.UIKeyboardWillChangeFrame, object: nil, queue: nil) { [weak self] notification in
self?.keyboardWillShow(notification)
}
// Deal with keyboard change (emoji, numerical, etc.)
NotificationCenter.default.addObserver(forName: NSNotification.Name.UITextInputCurrentInputModeDidChange, object: nil, queue: nil) { [weak self] notification in
self?.keyboardWillShow(notification)
}
NotificationCenter.default.addObserver(forName: NSNotification.Name.UIKeyboardWillHide, object: nil, queue: nil) { [weak self] notification in
self?.keyboardWillHide(notification)
}
}
func keyboardWillShow(_ notification: Notification) {
let verticalPadding: CGFloat = 20 // Padding between the bottom of the view and the top of the keyboard
guard let value = notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue else { return }
let keyboardHeight = value.cgRectValue.height
// Here you could have more complex rules, like checking if the textField currently selected is actually covered by the keyboard, but that's out of this scope.
self.bottomConstraint.constant = keyboardHeight + verticalPadding
UIView.animate(withDuration: 0.1, animations: { () -> Void in
self.view.layoutIfNeeded()
})
}
func keyboardWillHide(_ notification: Notification) {
self.bottomConstraint.constant = 0
UIView.animate(withDuration: 0.1, animations: { () -> Void in
self.view.layoutIfNeeded()
})
}
func stopObservingKeyboardChanges() {
NotificationCenter.default.removeObserver(self)
}
}
然后,要在UIViewController中实现它,执行以下操作:
let the viewController conform to this protocol :
class FormMailVC: UIViewControlle, KeyboardHandler {
start observing keyboard changes in viewWillAppear:
// MARK: - View controller life cycle
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
startObservingKeyboardChanges()
}
stop observing keyboard changes in viewWillDisappear:
override func viewWillDisappear(_ animated: Bool) {
super.viewWillDisappear(animated)
stopObservingKeyboardChanges()
}
create an IBOutlet for the bottom constraint from the storyboard:
// NSLayoutConstraints
@IBOutlet weak var bottomConstraint: NSLayoutConstraint!
(I recommend having all of your UI embedded inside a "contentView", and linking to this property the bottom constraint from this contentView to the bottom layout guide)
change the constraint priority of the top constraint to 250 (low)
这是为了让整个内容视图在键盘出现时向上滑动。
优先级必须低于子视图中的任何其他约束优先级,包括内容拥抱优先级/内容抗压缩优先级。
确保你的自动布局有足够的约束来决定contentView应该如何滑动。
你可能需要添加一个“大于等于”的约束:
给你!
struct MoveKeyboard {
static let KEYBOARD_ANIMATION_DURATION : CGFloat = 0.3
static let MINIMUM_SCROLL_FRACTION : CGFloat = 0.2;
static let MAXIMUM_SCROLL_FRACTION : CGFloat = 0.8;
static let PORTRAIT_KEYBOARD_HEIGHT : CGFloat = 216;
static let LANDSCAPE_KEYBOARD_HEIGHT : CGFloat = 162;
}
func textFieldDidBeginEditing(textField: UITextField) {
let textFieldRect : CGRect = self.view.window!.convertRect(textField.bounds, fromView: textField)
let viewRect : CGRect = self.view.window!.convertRect(self.view.bounds, fromView: self.view)
let midline : CGFloat = textFieldRect.origin.y + 0.5 * textFieldRect.size.height
let numerator : CGFloat = midline - viewRect.origin.y - MoveKeyboard.MINIMUM_SCROLL_FRACTION * viewRect.size.height
let denominator : CGFloat = (MoveKeyboard.MAXIMUM_SCROLL_FRACTION - MoveKeyboard.MINIMUM_SCROLL_FRACTION) * viewRect.size.height
var heightFraction : CGFloat = numerator / denominator
if heightFraction < 0.0 {
heightFraction = 0.0
} else if heightFraction > 1.0 {
heightFraction = 1.0
}
let orientation : UIInterfaceOrientation = UIApplication.sharedApplication().statusBarOrientation
if (orientation == UIInterfaceOrientation.Portrait || orientation == UIInterfaceOrientation.PortraitUpsideDown) {
animateDistance = floor(MoveKeyboard.PORTRAIT_KEYBOARD_HEIGHT * heightFraction)
} else {
animateDistance = floor(MoveKeyboard.LANDSCAPE_KEYBOARD_HEIGHT * heightFraction)
}
var viewFrame : CGRect = self.view.frame
viewFrame.origin.y -= animateDistance
UIView.beginAnimations(nil, context: nil)
UIView.setAnimationBeginsFromCurrentState(true)
UIView.setAnimationDuration(NSTimeInterval(MoveKeyboard.KEYBOARD_ANIMATION_DURATION))
self.view.frame = viewFrame
UIView.commitAnimations()
}
func textFieldDidEndEditing(textField: UITextField) {
var viewFrame : CGRect = self.view.frame
viewFrame.origin.y += animateDistance
UIView.beginAnimations(nil, context: nil)
UIView.setAnimationBeginsFromCurrentState(true)
UIView.setAnimationDuration(NSTimeInterval(MoveKeyboard.KEYBOARD_ANIMATION_DURATION))
self.view.frame = viewFrame
UIView.commitAnimations()
}
最后,因为我们使用委托方法
func textFieldShouldReturn(textField: UITextField) -> Bool {
textField.resignFirstResponder()
return true
}
使用objective-c重构http://www.cocoawithlove.com/2008/10/sliding-uitextfields-around-to-avoid.html
这是一个通用的解决方案,为所有的TextField
步骤,
1)创建一个由其他ViewController扩展的通用ViewController
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.keyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
if self.view.frame.origin.y == 0 {
self.view.frame.origin.y -= getMoveableDistance(keyboarHeight: keyboardSize.height)
}
}
}
@objc func keyboardWillHide(notification: NSNotification) {
if self.view.frame.origin.y != 0 {
self.view.frame.origin.y = 0
}
}
deinit {
NotificationCenter.default.removeObserver(self)
}
//get the distance to move up the main view for the focus textfiled
func getMoveableDistance(keyboarHeight : CGFloat) -> CGFloat{
var y:CGFloat = 0.0
if let activeTF = getSelectedTextField(){
var tfMaxY = activeTF.frame.maxY
var containerView = activeTF.superview!
while containerView.frame.maxY != self.view.frame.maxY{
let contViewFrm = containerView.convert(activeTF.frame, to: containerView.superview)
tfMaxY = tfMaxY + contViewFrm.minY
containerView = containerView.superview!
}
let keyboardMinY = self.view.frame.height - keyboarHeight
if tfMaxY > keyboardMinY{
y = (tfMaxY - keyboardMinY) + 10.0
}
}
return y
}
2)创建UIViewController和当前激活的TextField的扩展
//get active text field
扩展 UIViewController {
func getSelectedTextField() -> UITextField?{
let totalTextFields = getTextFieldsInView(view: self.view)
for textField in totalTextFields{
if textField.isFirstResponder{
return textField
}
}
return nil
}
func getTextFieldsInView(view: UIView) -> [UITextField] {
var totalTextFields = [UITextField]()
for subview in view.subviews as [UIView] {
if let textField = subview as? UITextField {
totalTextFields += [textField]
} else {
totalTextFields += getTextFieldsInView(view: subview)
}
}
return totalTextFields
}
}
我的做法如下:
class SignInController: UIViewController , UITextFieldDelegate {
@IBOutlet weak var scrollView: UIScrollView!
// outlet declartion
@IBOutlet weak var signInTextView: UITextField!
var kbHeight: CGFloat!
/**
*
* @method viewDidLoad
*
*/
override func viewDidLoad() {
super.viewDidLoad()
self.signInTextView.delegate = self
}// end viewDidLoad
/**
*
* @method viewWillAppear
*
*/
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(animated)
NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("keyboardWillShow:"), name: UIKeyboardWillShowNotification, object: nil)
NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("keyboardWillHide:"), name: UIKeyboardWillHideNotification, object: nil)
}// end viewWillAppear
/**
*
* @method viewDidAppear
*
*/
override func viewDidAppear(animated: Bool) {
super.viewDidAppear(animated)
}// end viewDidAppear
/**
*
* @method viewWillDisappear
*
*/
override func viewWillDisappear(animated: Bool) {
super.viewWillDisappear(animated)
NSNotificationCenter.defaultCenter().removeObserver(self)
}
/**
*
* @method textFieldShouldReturn
* retun the keyboard value
*
*/
// MARK -
func textFieldShouldReturn(textField: UITextField) -> Bool {
signInTextView.resignFirstResponder()
return true;
}// end textFieldShouldReturn
// MARK - keyboardWillShow
func keyboardWillShow(notification: NSNotification) {
if let userInfo = notification.userInfo {
if let keyboardSize = (userInfo[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue() {
kbHeight = keyboardSize.height
self.animateTextField(true)
}
}
}// end keyboardWillShow
// MARK - keyboardWillHide
func keyboardWillHide(notification: NSNotification) {
self.animateTextField(false)
}// end keyboardWillHide
// MARK - animateTextField
func animateTextField(up: Bool) {
var movement = (up ? -kbHeight : kbHeight)
UIView.animateWithDuration(0.3, animations: {
self.view.frame = CGRectOffset(self.view.frame, 0, movement)
})
}// end animateTextField
/**
*
* @method didReceiveMemoryWarning
*
*/
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}// end didReceiveMemoryWarning
}// end SignInController
Well, I think i might be too late but i found another simple version of Saqib's answer. I'm using Autolayout with constraints. I have a small view inside of another main view with username and password fields. Instead of changing the y coordinate of the view i'm saving the original constraint value in a variable and changing the constraint's constant to some value and again after the keyboard dismisses, i'm setting up the constraint to original one. This way it avoids the problem Saqib's answer has, (The view keeps on moving up and does not stop). Below is my code...
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);
self.originalConstraint = self.centerYConstraint.constant
}
func keyboardWillShow(sender: NSNotification) {
self.centerYConstraint.constant += 30
}
func keyboardWillHide(sender: NSNotification) {
self.centerYConstraint.constant = self.originalConstraint
}