UITextField Value Changed Event?

Question

How can I make it so that when the contents of a text field changes, a function is called?

kovpas · Accepted Answer · 2018-07-29T11:42:12.207

138

Objective-C

[myTextField addTarget:self 
                action:@selector(textFieldDidChange:) 
      forControlEvents:UIControlEventEditingChanged];

Swift 4

myTextField.addTarget(self, action: #selector(textFieldDidChange(sender:)), for: .editingChanged)

@objc func textFieldDidChange(sender: UITextField) {...}

edited Jul 29 '18 at 11:42

answered Oct 23 '10 at 21:42

kovpas

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Weird, based on UIControlEventDidEnd & UIControlEventDidBegin, one would assume that it was UIControlEventValueChanged... What exactly does UIControlEventValueChanged do then? – Jarrod Feb 22 '12 at 00:01
@kovpas if we change value programmatically then it didn't get call, any idea what to do ?. for example myTextField.text = "Krishna" – Krishna Sharma Jul 21 '20 at 17:37

score 26 · Answer 2 · answered Jan 25 '13 at 21:30

26

Actually, there is no value changed event for UITextField, use UIControlEventEditingChanged

answered Jan 25 '13 at 21:30

Dmitry Shevchenko

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score 8 · Answer 3 · answered Nov 11 '13 at 15:31

I resolved the issue changing the behavior of shouldChangeChractersInRange. If you return NO the changes won't be applied by iOS internally, instead you have the opportunity to change it manually and perform any actions after the changes.

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
    //Replace the string manually in the textbox
    textField.text = [textField.text stringByReplacingCharactersInRange:range withString:string];
    //perform any logic here now that you are sure the textbox text has changed
    [self didChangeTextInTextField:textField];
    return NO; //this make iOS not to perform any action
}

Note that setting text property will move cursor to the end of text, which might affect editing — jarnoh, Mar 04 '14 at 18:43

score 3 · Answer 4 · answered Jul 27 '18 at 06:53

3

this is my solution.

Swift 4

textField.addTarget(self, action: #selector(self.textFieldDidChange(sender:)), for: .editingChanged)

@objc func textFieldDidChange(sender: UITextField){
   print("textFieldDidChange is called")
}

answered Jul 27 '18 at 06:53

wsnjy

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1
7

score 2 · Answer 5 · answered Jul 19 '16 at 07:02

2

For swift this comes handy -

textField.addTarget(self, action: #selector(onTextChange), forControlEvents: UIControlEvents.EditingChanged)

answered Jul 19 '16 at 07:02

Vivek Bansal

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UITextField Value Changed Event?

5 Answers5

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