Set maxlength to specific UITextField

Question

i tried to set maxlength to my UITextfield but it also affects my other UITextfield.

i tried to use :

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
    // Prevent crashing undo bug – see note below.
    if(range.length + range.location > textField.text.length)
    {
        return NO;
    }

    NSUInteger newLength = [textField.text length] + [string length] - range.length;
    return newLength <= 25;
}

i would like to set maxlength to specific uitextfield only.

Add a check: `if (textField == myTextField) { //what you did goes here }` — Yun CHEN, May 07 '18 at 09:33
You need to add tag to the textfield, and compare the tag in shouldChangeCharactersInRange method — Vinaykrishnan, May 07 '18 at 09:45

score 0 · Accepted Answer · answered May 07 '18 at 09:41

First, check the editing textfield. Then check the length of the string

- (BOOL)textField:(UITextField *) textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {

    /// always allow other textfields
    if (textField != specificTextfield) {
         return YES;
    }

    /// check max length

    NSUInteger oldLength = [textField.text length];
    NSUInteger replacementLength = [string length];
    NSUInteger rangeLength = range.length;

    NSUInteger newLength = oldLength - rangeLength + replacementLength;

    BOOL returnKey = [string rangeOfString: @"\n"].location != NSNotFound;

    return newLength <= MAXLENGTH || returnKey;
}

Ref: Set UITextField Maximum Length

Vinaykrishnan · Answer 2 · 2018-05-07T14:12:33.800

Add tag to your textfield. and in the delegate shouldChangeCharactersInRange method check whether the textfield corresponds to the particular tag.

#define MAXLENGTH 10

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{
if (textField.tag == 1){
    NSUInteger oldLength = [textField.text length];
    NSUInteger replacementLength = [string length];
    NSUInteger rangeLength = range.length;
    NSUInteger newLength = oldLength - rangeLength + replacementLength;
    BOOL returnKey = [string rangeOfString: @"\n"].location != NSNotFound;
    return newLength <= MAXLENGTH || returnKey;
}
return true;
}

score -1 · Answer 3 · edited May 07 '18 at 09:58

-1

It is for swift, Try this

func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
    let length = ((txtPhoneNumber.text?.count)! - range.length) + string.count
    if length <= 9 {
        return true
    }
    return false
}

edited May 07 '18 at 09:58

M Reza

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answered May 07 '18 at 09:37

Jatin Patel

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i used objective - c – KikX May 07 '18 at 09:42

Set maxlength to specific UITextField

3 Answers3