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")
}
}
这是一个改进版的@JosephLord和@Hlung的回答。
无论你是否有标签栏，它都适用。
并且它可以完美地恢复由键盘移动到原始位置的视图。
// You have to set this up in storyboard first!.
// It's a vertical spacing constraint between view and bottom of superview.
@IBOutlet weak var bottomSpacingConstraint: NSLayoutConstraint!
override func viewDidLoad() {
super.viewDidLoad()
// Receive(Get) Notification
NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardNotification:", name: UIKeyboardWillShowNotification, object: nil)
NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardNotification:", name: UIKeyboardWillHideNotification, object: nil)
self.originalConstraint = self.keyboardHeightLayoutConstraint?.constant //for original coordinate.
}
func keyboardNotification(notification: NSNotification) {
let isShowing = notification.name == UIKeyboardWillShowNotification
var tabbarHeight: CGFloat = 0
if self.tabBarController? != nil {
tabbarHeight = self.tabBarController!.tabBar.frame.height
}
if let userInfo = notification.userInfo {
let endFrame = (userInfo[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.CGRectValue()
let duration:NSTimeInterval = (userInfo[UIKeyboardAnimationDurationUserInfoKey] as? NSNumber)?.doubleValue ?? 0
let animationCurveRawNSN = userInfo[UIKeyboardAnimationCurveUserInfoKey] as? NSNumber
let animationCurveRaw = animationCurveRawNSN?.unsignedLongValue ?? UIViewAnimationOptions.CurveEaseInOut.rawValue
let animationCurve:UIViewAnimationOptions = UIViewAnimationOptions(rawValue: animationCurveRaw)
self.keyboardHeightLayoutConstraint?.constant = isShowing ? (endFrame!.size.height - tabbarHeight) : self.originalConstraint!
UIView.animateWithDuration(duration,
delay: NSTimeInterval(0),
options: animationCurve,
animations: { self.view.layoutIfNeeded() },
completion: nil)
}
}
我已采取以下方式:
当textfield superview为view时，这很有用
class AdminLoginViewController: UIViewController,
UITextFieldDelegate{
@IBOutlet weak var txtUserName: UITextField!
@IBOutlet weak var txtUserPassword: UITextField!
@IBOutlet weak var btnAdminLogin: UIButton!
private var activeField : UIView?
var param:String!
var adminUser : Admin? = nil
var kbHeight: CGFloat!
override func viewDidLoad()
{
self.addKeyBoardObserver()
self.addGestureForHideKeyBoard()
}
override func viewWillDisappear(animated: Bool) {
super.viewWillDisappear(animated)
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
func addGestureForHideKeyBoard()
{
let tapGesture = UITapGestureRecognizer(target: self, action: Selector("hideKeyboard"))
tapGesture.cancelsTouchesInView = false
view.addGestureRecognizer(tapGesture)
}
func hideKeyboard() {
self.view.endEditing(true)
}
func addKeyBoardObserver(){
NSNotificationCenter.defaultCenter().addObserver(self, selector: "willChangeKeyboardFrame:",
name:UIKeyboardWillShowNotification, object: nil)
NSNotificationCenter.defaultCenter().addObserver(self, selector: "willChangeKeyboardFrame:",
name:UIKeyboardWillHideNotification, object: nil)
}
func removeObserver(){
NSNotificationCenter.defaultCenter().removeObserver(self)
}
//MARK:- textfiled Delegate
func textFieldShouldBeginEditing(textField: UITextField) -> Bool
{
activeField = textField
return true
}
func textFieldShouldEndEditing(textField: UITextField) -> Bool
{
if activeField == textField
{
activeField = nil
}
return true
}
func textFieldShouldReturn(textField: UITextField) -> Bool {
if txtUserName == textField
{
txtUserPassword.becomeFirstResponder()
}
else if (textField == txtUserPassword)
{
self.btnAdminLoginAction(nil)
}
return true;
}
func willChangeKeyboardFrame(aNotification : NSNotification)
{
if self.activeField != nil && self.activeField!.isFirstResponder()
{
if let keyboardSize = (aNotification.userInfo![UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue()
{
let dy = (self.activeField?.superview?.convertRect((self.activeField?.frame)!, toView: view).origin.y)!
let height = (self.view.frame.size.height - keyboardSize.size.height)
if dy > height
{
var frame = self.view.frame
frame.origin.y = -((dy - height) + (self.activeField?.frame.size.height)! + 20)
self.view.frame = frame
}
}
}
else
{
var frame = self.view.frame
frame.origin.y = 0
self.view.frame = frame
}
} }
下面是一个简单的解决方案，其中文本字段有一个约束将其绑定到底部布局指南。它只是将键盘高度添加到约束常数中。
// This constraint ties the text field to the bottom layout guide
@IBOutlet var textFieldToBottomLayoutGuideConstraint: NSLayoutConstraint!
override func viewDidLoad() {
super.viewDidLoad()
NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWillShow:", name:UIKeyboardWillShowNotification, object: nil);
NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWillHide:", name:UIKeyboardWillHideNotification, object: nil);
}
func keyboardWillShow(sender: NSNotification) {
if let keyboardSize = (sender.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue() {
self.textFieldToBottomLayoutGuideConstraint?.constant += keyboardSize.height
}
}
func keyboardWillHide(sender: NSNotification) {
if let keyboardSize = (sender.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue() {
self.textFieldToBottomLayoutGuideConstraint?.constant -= keyboardSize.height
}
}
编辑:我推荐一个更简单、更干净的解决方案。只需将底部间距约束的类更改为KeyboardLayoutConstraint。它会自动展开到键盘高度。
这是一个改进版的@JosephLord的回答。
在iOS 8.3 iPad模拟器上测试，Portrait。Xcode6.3 beta4，我发现他的答案不工作时，键盘隐藏，因为UIKeyboardFrameEndUserInfoKey是“NSRect:{{0, 1024}，{768, 264}}”;高度不为0。
这回到使用传统的UIKeyboardWillShowNotification和UIKeyboardWillHideNotification来更好地判断键盘何时隐藏，而不是依赖于结束帧的高度。UIKeyboardWillShowNotification也会在键盘帧改变时发送，所以它应该覆盖所有的用例。
// You have to set this up in storyboard first!.
// It's a vertical spacing constraint between view and bottom of superview.
@IBOutlet weak var bottomSpacingConstraint: NSLayoutConstraint!
override func viewDidLoad() {
super.viewDidLoad()
NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("keyboardNotification:"), name:UIKeyboardWillShowNotification, object: nil);
NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("keyboardNotification:"), name:UIKeyboardWillHideNotification, object: nil);
}
deinit {
NSNotificationCenter.defaultCenter().removeObserver(self)
}
func keyboardNotification(notification: NSNotification) {
let isShowing = notification.name == UIKeyboardWillShowNotification
if let userInfo = notification.userInfo {
let endFrame = (userInfo[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.CGRectValue()
let endFrameHeight = endFrame?.size.height ?? 0.0
let duration:NSTimeInterval = (userInfo[UIKeyboardAnimationDurationUserInfoKey] as? NSNumber)?.doubleValue ?? 0
let animationCurveRawNSN = userInfo[UIKeyboardAnimationCurveUserInfoKey] as? NSNumber
let animationCurveRaw = animationCurveRawNSN?.unsignedLongValue ?? UIViewAnimationOptions.CurveEaseInOut.rawValue
let animationCurve:UIViewAnimationOptions = UIViewAnimationOptions(rawValue: animationCurveRaw)
self.bottomSpacingConstraint?.constant = isShowing ? endFrameHeight : 0.0
UIView.animateWithDuration(duration,
delay: NSTimeInterval(0),
options: animationCurve,
animations: { self.view.layoutIfNeeded() },
completion: nil)
}
}
