xcode 4.2.1 - limiting character length in TextField

Question

I have been trying to limit a textField by many codes available out there in the internet but with no luck.

I have added UIViewController<UITextFieldDelegate> in my header file

and textField.delegate = self; in my viewDidLoad

and implemented the following fundtion in my .m file:

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
    NSString *newString = [textField.text stringByReplacingCharactersInRange:range withString:string];
    return !([newString length] > 5);
}

this stil does not limit my text field. any idea?

possible duplicate of [iPhone SDK: Set Max Character length TextField](http://stackoverflow.com/questions/433337/iphone-sdk-set-max-character-length-textfield) — Ilanchezhian, Feb 27 '12 at 07:19
What have you done to try to debug it? Have you tried logging the `[newString length]`, for example? — dbrajkovic, Feb 27 '12 at 07:22
I use the simulator. and enter the character from a custom made keyboard — Jan, Feb 27 '12 at 08:17
Is it custom made keyboard? Then, are you geting any call back when a key is pressed and before appending that key value to the string? — Ilanchezhian, Feb 27 '12 at 09:06

score 2 · Accepted Answer · edited May 23 '17 at 12:12

2

Do it as following as it has been the exact duplicate of this

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
    NSUInteger newLength = [textField.text length] + [string length] - range.length;
    return (newLength > 5) ? NO : YES;
}

edited May 23 '17 at 12:12

Community

1
1

answered Feb 27 '12 at 07:26

Ilanchezhian

17,426
1
53
55

score 0 · Answer 2 · answered Feb 27 '12 at 07:22

0

The replacement string is just the 1 character that was pressed, not the whole string so you need to add It to the current textfield.text before counting. Your count is probably always 1 (or more if pasting a word)

answered Feb 27 '12 at 07:22

Darren

10,182
20
95
162

Your newstring only contains the replacement string which is only the new character entered, so it is always only 1 character. You new to add textfield.text to newstring to get the full string. Maybe with stringwithformat:@"%@%@",textfield.text,replacementstring]; then count it. – Darren Feb 27 '12 at 09:07

score 0 · Answer 3 · answered Feb 27 '12 at 07:24

I implement this in my code and it works:

This code eliminate all the letters only accept numbers, but like I delete the character, you could delete everything that its over length 5 and it keeps a nice effect that appears and disappears

- (void)textFieldDidBeginEditing:(UITextField *)textField {
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(textChanged:) name:UITextFieldTextDidChangeNotification object:textField];
}


- (void)textChanged:(NSNotification *)textField {
    NSString *text = [[textField object] text];
    NSString *last = [text substringFromIndex:[text length] -1];
    NSArray *accept = [NSArray arrayWithObjects:@"0", @"1", @"2", @"3", @"4", @"5", @"6", @"7" , @"8", @"9", @".", nil];

    for (int i=0; i<[accept count]; i++) {
        NSLog(@"%@", [accept objectAtIndex:i]);
        if (![last isEqualToString:[accept objectAtIndex:i]]) {
            [[textField object] setText:[text substringToIndex:[text length]-1]];
        }
    }
}

This code does not specify the limit size and it gives me errors when debugging says: Range or index out of bounds — Jan, Feb 27 '12 at 07:41
juts check if the length its over 5 eliminate the last character — Eduardo Iglesias, Feb 27 '12 at 18:18

xcode 4.2.1 - limiting character length in TextField

3 Answers3