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")
}
}
以下是我对Swift 2.2的解决方案:
首先注册键盘显示/隐藏通知
NSNotificationCenter.defaultCenter().addObserver(self,
selector: #selector(MessageThreadVC.keyboardWillShow(_:)),
name: UIKeyboardWillShowNotification,
object: nil)
NSNotificationCenter.defaultCenter().addObserver(self,
selector: #selector(MessageThreadVC.keyboardWillHide(_:)),
name: UIKeyboardWillHideNotification,
object: nil)
然后在与这些通知相对应的方法中，向上或向下移动主视图
func keyboardWillShow(sender: NSNotification) {
if let keyboardSize = (sender.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.CGRectValue() {
self.view.frame.origin.y = -keyboardSize.height
}
}
func keyboardWillHide(sender: NSNotification) {
self.view.frame.origin.y = 0
}
诀窍在于“keyboardWillShow”部分，每次“QuickType建议栏”被展开或折叠时，该部分都会被调用。然后我们总是设置主视图的y坐标等于键盘总高度的负值(包括或不包括“QuickType栏”部分)。
最后不要忘记删除观察者
deinit {
NSNotificationCenter.defaultCenter().removeObserver(self)
}
func registerForKeyboardNotifications(){
//Keyboard
NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(keyboardWasShown), name: UIKeyboardDidShowNotification, object: nil)
NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(keyboardWillBeHidden), name: UIKeyboardDidHideNotification, object: nil)
}
func deregisterFromKeyboardNotifications(){
NSNotificationCenter.defaultCenter().removeObserver(self, name: UIKeyboardWillShowNotification, object: nil)
NSNotificationCenter.defaultCenter().removeObserver(self, name: UIKeyboardWillHideNotification, object: nil)
}
func keyboardWasShown(notification: NSNotification){
let userInfo: NSDictionary = notification.userInfo!
let keyboardInfoFrame = userInfo.objectForKey(UIKeyboardFrameEndUserInfoKey)?.CGRectValue()
let windowFrame:CGRect = (UIApplication.sharedApplication().keyWindow!.convertRect(self.view.frame, fromView:self.view))
let keyboardFrame = CGRectIntersection(windowFrame, keyboardInfoFrame!)
let coveredFrame = UIApplication.sharedApplication().keyWindow!.convertRect(keyboardFrame, toView:self.view)
let contentInsets = UIEdgeInsetsMake(0, 0, (coveredFrame.size.height), 0.0)
self.scrollViewInAddCase .contentInset = contentInsets;
self.scrollViewInAddCase.scrollIndicatorInsets = contentInsets;
self.scrollViewInAddCase.contentSize = CGSizeMake((self.scrollViewInAddCase.contentSize.width), (self.scrollViewInAddCase.contentSize.height))
}
/**
this method will fire when keyboard was hidden
- parameter notification: contains keyboard details
*/
func keyboardWillBeHidden (notification: NSNotification) {
self.scrollViewInAddCase.contentInset = UIEdgeInsetsZero
self.scrollViewInAddCase.scrollIndicatorInsets = UIEdgeInsetsZero
}
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
}
} }
如果视图上有多个文本字段，那么我建议您查看这个方法。当在字段之间切换时，你不会有视图跑开的问题，它会简单地适应所需的文本字段。它在swift 5中工作
override func viewDidLoad() {
super.viewDidLoad()
registerForKeyboardNotification()
}
扩展中的所有方法
extension StartViewController: UITextFieldDelegate {
func registerForKeyboardNotification() {
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow(sender:)), name: UIResponder.keyboardWillShowNotification, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide(sender:)), name: UIResponder.keyboardWillHideNotification, object: nil)
}
@objc func keyboardWillShow(sender: NSNotification) {
guard let userInfo = sender.userInfo,
let keyboardFrame = userInfo[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue,
let currentTextField = UIResponder.currentFirst() as? UITextField else { return }
let keyboardTopY = keyboardFrame.cgRectValue.origin.y
let convertedTextFieldFrame = view.convert(currentTextField.frame, from: currentTextField.superview)
let textFieldBottomY = convertedTextFieldFrame.origin.y + convertedTextFieldFrame.size.height
if textFieldBottomY > keyboardTopY {
let textBoxY = convertedTextFieldFrame.origin.y
let newFrameY = (textBoxY - keyboardTopY / 2) * -1
view.frame.origin.y = newFrameY
}
}
@objc func keyboardWillHide(sender: NSNotification) {
self.view.frame.origin.y = 0
}
func textFieldShouldReturn(_ textField: UITextField) -> Bool {
switch textField {
case emailTextField :
passwordTextField.becomeFirstResponder()
default:
emailTextField.becomeFirstResponder()
}
return true
}
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
super.touchesBegan(touches , with:event)
view.endEditing(true)
}
}
最后我们用UIResponder建立方法
extension UIResponder {
private struct Static {
static weak var responder: UIResponder?
}
static func currentFirst() -> UIResponder? {
Static.responder = nil
UIApplication.shared.sendAction(#selector(UIResponder._trap), to: nil, from: nil, for: nil)
return Static.responder
}
@objc private func _trap() {
Static.responder = self
}
}
