How do I check when a UITextField changes

Question

I am trying to check when a text field changes  equivalent too the function used for textView - textViewDidChange so far I have done this      func textFieldDidBeginEditing textField  UITextField            if self status text        amp  amp  self username text                     self topRightButton enabled   false           else                  self topRightButton enabled   true                   Which kind of works  but the topRightButton is enabled as soon as the text field is pressed on  I want it to be enabled only when text is actually typed in

User · Answer

Just in case you are interested in a SwiftUI solution, this it's working for me:

 TextField("write your answer here...",
            text: Binding(
                     get: {
                        return self.query
                       },
                     set: { (newValue) in
                        self.fetch(query: newValue) // any action you need
                                return self.query = newValue
                      }
            )
  )

I have to say it's not my idea, I read it in this blog: SwiftUI binding: A very simple trick

User · Answer

Swift 3   textField addTarget self  action   selector ViewController textFieldDidChange sender     for  UIControlEvents editingChanged

User · Answer

txf Subject addTarget self  action  selector didChangeFirstText   for   editingChanged    objc func didChangeText textField UITextField        let str   textField text     if str  contains                 let newstr   str  replacingOccurrences of       with              textField text   newstr           objc func didChangeFirstText textField UITextField        if textField text                  textField text

User · Answer

You can use this delegate method from UITextFieldDelegate  It fires with every character change    Objective C  textField shouldChangeCharactersInRange replacementString   Swift  textField   shouldChangeCharactersInRange replacementString     However THIS ONLY FIRES BEFORE a change is made  indeed  a change is only made if you do return true from here

User · Answer

You can make this connection in interface builder    In your storyboard  click the assistant editor at the top of the screen  two circles in the middle    Ctrl   Click on the textfield in interface builder  Drag from EditingChanged to inside your view controller class in the assistant view   Name your function   textDidChange  for example  and click connect

User · Answer

Swift 3 0 1   Some of the other swift 3 0 answers are not up to date   textField addTarget self  action   selector ViewController textFieldDidChange                                 for  UIControlEvents editingChanged   func textFieldDidChange   textField  UITextField

User · Answer

This is how you can add a textField text change listener using Swift 3   Declare your class as UITextFieldDelegate  override func viewDidLoad         super viewDidLoad        textField delegate   self      textField addTarget self  action   selector UITextFieldDelegate textFieldShouldEndEditing       for  UIControlEvents editingChanged      Then just traditionally add a textFieldShouldEndEditing function   func textFieldShouldEndEditing   textField  UITextField  - gt  Bool      do stuff         return true

User · Answer

The way I ve handled it so far  in  UITextFieldDelegate  func textField textField  UITextField  shouldChangeCharactersInRange range  NSRange  replacementString string  String  - gt  Bool          text hasn t changed yet  you have to compute the text AFTER the edit yourself     let updatedString    textField text as NSString    stringByReplacingCharactersInRange range  withString  string          do whatever you need with this updated string  your code           always return true so that changes propagate     return true     Swift4 version   func textField   textField  UITextField  shouldChangeCharactersIn range  NSRange  replacementString string  String  - gt  Bool       let updatedString    textField text as NSString    replacingCharacters in  range  with  string      return true

User · Answer

Maybe use RxSwift    need  pod  RxSwift         gt  3 0  pod  RxCocoa         gt  3 0    add imports obviously  import RxSwift import RxCocoa   So u have a textfield   UITextField  let observable  Observable lt String  gt    textField rx text asObservable   observable subscribe              onNext    string  String   in                 print string                U have other 3 methods     onError onCompleted onDisposed onNext

User · Answer

Swift 4  textField addTarget self  action   selector textIsChanging   for  UIControlEvents editingChanged    objc func textIsChanging   textField UITextField      print   TextField is changing        If you want to make a change once the user has typed in completely  It will be called once user dismiss keyboard or press enter    textField addTarget self  action   selector textDidChange   for  UIControlEvents editingDidEnd     objc func textDidChange   textField UITextField            print   TextField did changed

User · Answer

SWIFT  Swift 4 2  textfield addTarget self  action   selector ViewController textFieldDidChange       for   editingChanged    and   objc func textFieldDidChange   textField  UITextField         SWIFT 3  amp  swift 4 1  textField addTarget self  action   selector ViewController textFieldDidChange       for   editingChanged    and  func textFieldDidChange   textField  UITextField         SWIFT 2 2  textField addTarget self  action   selector ViewController textFieldDidChange       forControlEvents  UIControlEvents EditingChanged    and  func textFieldDidChange textField  UITextField          your code     OBJECTIVE-C   textField addTarget self action  selector textFieldDidChange   forControlEvents UIControlEventEditingChanged     and textFieldDidChange method is  - void textFieldDidChange   UITextField    textField        your code

User · Answer

Swift 4 2  write this in viewDidLoad     to detect if TextField changed TextField addTarget self  action   selector textFieldDidChange                                          for  UIControl Event editingChanged    write this outside viewDidLoad   objc func textFieldDidChange   textField  UITextField           do something     You could change the event by UIControl Event editingDidBegin or what ever you want to detect

User · Answer

There s now a UITextField delegate method available on iOS13  optional func textFieldDidChangeSelection   textField  UITextField

User · Answer

swift 4  In viewDidLoad           ADD BUTTON TO DISMISS KEYBOARD         Init a keyboard toolbar      let toolbar   UIView frame  CGRect x  0  y  view frame size height 44  width  view frame size width  height  44       toolbar backgroundColor   UIColor clear         Add done button     let doneButt   UIButton frame  CGRect x  toolbar frame size width - 60  y  0  width  44  height  44       doneButt setTitle  Done   for   normal      doneButt setTitleColor MAIN COLOR  for   normal      doneButt titleLabel  font   UIFont name   Titillium-Semibold   size  13      doneButt addTarget self  action   selector dismissKeyboard   for   touchUpInside      toolbar addSubview doneButt       USDTextField inputAccessoryView   toolbar   Add this function        objc func dismissKeyboard             Causes the view  or one of its embedded text fields  to resign the first responder status        view endEditing true

User · Answer

textField   shouldChangeCharactersIn replacementString   worked for me in Xcode 8  Swift 3 if you want to check every single keypress   func textField   textField  UITextField  shouldChangeCharactersIn range  NSRange  replacementString string  String  - gt  Bool           Whatever code you want to run here         Keep in mind that the textfield hasn t yet been updated         so use  string  instead of  textField text  if you want to        access the string the textfield will have after a user presses a key      var statusText   self status text     var usernameText   self username text      switch textField      case self status          statusText   string     case self username          usernameText   string     default          break            if statusText        amp  amp  usernameText                 self topRightButton enabled   false       else              self topRightButton enabled   true              Return false if you don t want the textfield to be updated     return true

User · Answer

You should follow this steps    Make a Outlet reference to the textfield AssignUITextFieldDelegate to the controller class  Configure yourTextField delegate Implement whatever function you need   Sample code   import UIKit  class ViewController  UIViewController  UITextFieldDelegate         IBOutlet var yourTextFiled   UITextField       override func viewDidLoad             super viewDidLoad            yourTextFiled delegate   self             func textFieldDidEndEditing   textField  UITextField               your code            func textFieldShouldReturn   textField  UITextField  - gt  Bool              your code

User · Answer

Swift 4  Conform to UITextFieldDelegate   func textField   textField  UITextField  shouldChangeCharactersIn range  NSRange  replacementString string  String  - gt  Bool          figure out what the new string will be after the pending edit     let updatedString    textField text as NSString    replacingCharacters in  range  with  string          Do whatever you want here          Return true so that the change happens     return true

User · Answer

In case it is not possible to bind the addTarget to your UITextField  I advise you to bind one of them as suggested above  and insert the code for execution at the end of the shouldChangeCharactersIn method   nameTextField addTarget self  action   selector RegistrationViewController textFieldDidChange       for   editingChanged    objc func textFieldDidChange   textField  UITextField        if phoneNumberTextField text  count    17  amp  amp  nameTextField text  count  gt  0           continueButtonOutlet backgroundColor   UIColor  green        else           continueButtonOutlet backgroundColor    systemGray           And in call in shouldChangeCharactersIn func   func textField   textField  UITextField  shouldChangeCharactersIn range  NSRange  replacementString string  String  - gt  Bool        guard let text   textField text else           return true           let lastText    text as NSString  replacingCharacters in  range  with  string  as String      if phoneNumberTextField    textField           textField text   lastText format   7 NNN -NNN-NN-NN   oldString  text          textFieldDidChange phoneNumberTextField          return false           return true

User · Answer

Swift 5 0  textField addTarget self  action   selector ViewController textFieldDidChange                                 for   editingChanged    and handle method    objc func textFieldDidChange   textField  UITextField         Swift 4 0  textField addTarget self  action   selector ViewController textFieldDidChange                                 for  UIControlEvents editingChanged    and handle method    objc func textFieldDidChange   textField  UITextField         Swift 3 0  textField addTarget self  action   selector textFieldDidChange textField     for   editingChanged    and handle method   func textFieldDidChange textField  UITextField

[ios] How do I check when a UITextField changes?

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