Using `textField:shouldChangeCharactersInRange:`, how do I get the text including the current typed character?

Question

I'm using the code below to try and have textField2's text content get updated to match textField1's whenever the user types in textField1.

- (BOOL) textField: (UITextField *)theTextField shouldChangeCharactersInRange: (NSRange)range replacementString: (NSString *)string {    
  if (theTextField == textField1){    
     [textField2 setText:[textField1 text]];    
  }
}

However, the output I observe is that...

textField2 is "12", when textField1 is "123"

textField2 is "123", when textField1 is "1234"

... when what I want is:

textField2 is "123", when textField1 is "123"

textField2 is "1234", when textField1 is "1234"

What am I doing wrong?

Just a reminder it is staggeringly easier to always use the **"Editing Changed" event** .. just drag it in IB to a function you make. — Fattie, Dec 10 '13 at 17:27
Note the editing changed event does not capture any text changing events generated programmatically, e.g. autocorrect/autocompletion/text replacement. — shim, Mar 16 '20 at 18:00

score 273 · Accepted Answer · answered Feb 04 '10 at 08:21

273

-shouldChangeCharactersInRange gets called before text field actually changes its text, that's why you're getting old text value. To get the text after update use:

[textField2 setText:[textField1.text stringByReplacingCharactersInRange:range withString:string]];

answered Feb 04 '10 at 08:21

Vladimir

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15

This *almost* worked for me. If I typed a character, this worked. If I pressed the delete button, it'd delete two characters. For me, the following suggestion worked: http://stackoverflow.com/questions/388237/getting-the-value-of-a-uitextfield-as-keystrokes-are-entered Basically, drag'n'drop from the UITextField into your code (to create a function), then right-click on your TextField, and drag'n'drop from the circle for the "Editing Changed" to your new function. (Sigh. I miss Visual Studio sometimes..) – Mike Gledhill May 12 '13 at 18:33
I also feel this is a valid answer, but not THE answer. The best way to accomplish what you want was answered by @tomute – Pedro Borges Sep 09 '14 at 09:08
5

Or textFiel.text = (textFiel.text as NSString).stringByReplacingCharactersInRange(range, withString: string) in Swift – Max Nov 17 '14 at 10:16
@MikeGledhill You can do the same thing programmatically: `[textField addTarget:self action:@selector(textFieldEditingChanged:) forControlEvents:UIControlEventEditingChanged]` – Steve Moser Jun 19 '17 at 18:11

score 53 · Answer 2 · answered Apr 01 '13 at 12:58

-(BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
    NSString * searchStr = [textField.text stringByReplacingCharactersInRange:range withString:string];

    NSLog(@"%@",searchStr);
    return YES;
}

score 42 · Answer 3 · answered Nov 01 '16 at 14:59

42

Swift 3

Based on the accepted answer, the following should work in Swift 3:

func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {

    let newString = NSString(string: textField.text!).replacingCharacters(in: range, with: string)

    return true
}

Note

Both String and NSString have methods called replacingCharacters:inRange:withString. However, as expected, the former expects an instance of Range, while the latter expects an instance of NSRange. The textField delegate method uses an NSRange instance, thus the use of NSString in this case.

answered Nov 01 '16 at 14:59

focorner

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24

`replacingCharacters` should be `stringByReplacingCharactersInRange` – Alan Scarpa Nov 07 '16 at 15:58
1

@Alan_s I copied this snippet directly from my Xcode project and it was working fine. Are you using Xcode 8.1 with target to iOS 10.1? – focorner Nov 07 '16 at 17:05

score 26 · Answer 4 · edited May 23 '17 at 11:47

26

Instead of using the UITextFieldDelegate, try to use "Editing Changed" event of UITextField.

edited May 23 '17 at 11:47

Community

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1

answered Feb 04 '10 at 08:21

tomute

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bauerMusic · Answer 5 · 2020-05-28T02:50:34.407

In Swift(4), without NSString (pure Swift):

func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {

    if let textFieldString = textField.text, let swtRange = Range(range, in: textFieldString) {

        let fullString = textFieldString.replacingCharacters(in: swtRange, with: string)

        print("FullString: \(fullString)")
    }

    return true
}

As an extension:

extension UITextField {

    func fullTextWith(range: NSRange, replacementString: String) -> String? {

        if let fullSearchString = self.text, let swtRange = Range(range, in: fullSearchString) {

            return fullSearchString.replacingCharacters(in: swtRange, with: replacementString)
        }

        return nil
    }
}

// Usage:

func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {

    if let textFieldString = textField.fullTextWith(range: range, replacementString: string) {
        print("FullString: \(textFieldString)")
    }

    return true
}

score 8 · Answer 6 · answered Nov 20 '15 at 16:39

Swift version for it :

func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool {

    if string == " " {
        return false
    }

    let userEnteredString = textField.text

    var newString = (userEnteredString! as NSString).stringByReplacingCharactersInRange(range, withString: string) as NSString

    print(newString)

    return true
}

score 5 · Answer 7 · answered Feb 04 '10 at 08:21

5

This is the code you need,

if ([textField isEqual:self.textField1])
  textField2.text = [textField1.text stringByReplacingCharactersInRange:range withString:string];

answered Feb 04 '10 at 08:21

Deepak Danduprolu

44,595
12
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score 1 · Answer 8 · answered Aug 12 '16 at 08:07

use guard

func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool {
        guard case let textFieldString as NSString = textField.text where
            textFieldString.stringByReplacingCharactersInRange(range, withString: string).length <= maxLength else {
                return false
        }
        return true
    }

score 0 · Answer 9 · answered Jan 10 '14 at 11:17

My solution is to use UITextFieldTextDidChangeNotification.

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(copyText:) name:UITextFieldTextDidChangeNotification object:nil];

Don't forget to call [[NSNotificationCenter defaultCenter] removeObserver:self]; in dealloc method.

score 0 · Answer 10 · answered Apr 11 '17 at 14:49

0

If you need to replace the textfield text with this you can use my solution (Swift 3): https://gist.github.com/Blackjacx/2198d86442ec9b9b05c0801f4e392047

After the replacement you can just get textField.text to retrieve the composed text.

answered Apr 11 '17 at 14:49

blackjacx

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Using `textField:shouldChangeCharactersInRange:`, how do I get the text including the current typed character?

10 Answers10

Swift 3

Note

Linked