Tuesday, February 28, 2012

xcode 4.2.1 - limiting character length in TextField


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?

3 comments:

  1. 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;
    }

    ReplyDelete
  2. 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)

    ReplyDelete
  3. 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]];
    }
    }
    }

    ReplyDelete