textViewのdelegateモニタユーザの正しい姿勢

- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text {
    
    NSString *targetString = [textView.text stringByReplacingCharactersInRange:range withString:text];

    if (targetString.length  > _inputCount) {
        textView.text = [targetString substringToIndex:_inputCount];
        return NO;
    }
    return YES;
}