- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
    if (range.location > 0 && range.length == 1 && string.length == 0)
    {
        textField.text = [textField.text substringToIndex:
 
textField.text.length - 1];
        return NO;
    }
    return YES;
}

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
    {
        if (range.location > 0 && range.length == 1 && string.length == 0)
        {
            // Stores cursor position
            UITextPosition *beginning = textField.beginningOfDocument;
            UITextPosition *start = [textField positionFromPosition:beginning offset:range.location];
            NSInteger cursorOffset = [textField offsetFromPosition:beginning toPosition:start] + string.length;
            // Save the current text, in case iOS deletes the whole text
            NSString *text = textField.text;
            // Trigger deletion
            [textField deleteBackward];
            // iOS deleted the entire string
            if (textField.text.length != text.length - 1)
            {
                textField.text = [text stringByReplacingCharactersInRange:range withString:string];
                // Update cursor position
                UITextPosition *newCursorPosition = [textField positionFromPosition:textField.beginningOfDocument offset:cursorOffset];
                UITextRange *newSelectedRange = [textField textRangeFromPosition:newCursorPosition toPosition:newCursorPosition];
                [textField setSelectedTextRange:newSelectedRange];
            }
            return NO;
        }
        return YES;
    }