IOS UITextView 和 UITextField 联想输入法字数限制

UITextField  输入限制

  [_tfTextFeild addTarget:self action:@selector(limitLength:) forControlEvents:UIControlEventEditingChanged];

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
    if (textField == _tfTextFeild)
    {
        if (string.length == 0) return YES;
        
        NSInteger existedLength = textField.text.length;
        NSInteger selectedLength = range.length;
        NSInteger replaceLength = string.length;
        if (existedLength - selectedLength + replaceLength > TEXT_MAXLENGTH)
        {
            return NO;
        }
    }
    
    return YES;
}

- (void)limitLength:(UITextField *)textField
{
    if (textField == _tfTextFeild)
    {
        if (textField.text.length > TEXT_MAXLENGTH)
        {
            textField.text = [textField.text substringToIndex:TEXT_MAXLENGTH];
        }
    }
}

UITextView输入限制

 [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(textViewEditChanged) name:UITextViewTextDidChangeNotification object:nil];

- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text
{
    if (textView == _contentTextView)
    {
        if (text.length == 0) return YES;
        
        NSInteger existedLength = textView.text.length;
        NSInteger selectedLength = range.length;
        NSInteger replaceLength = text.length;
        if (existedLength - selectedLength + replaceLength > TEXT_MAXLENGTH)
        {
            return NO;
        }
    }
    
    return YES;
}

- (void)textViewEditChanged
{
    if (_contentTextView.text.length > TEXT_MAXLENGTH)
    {
       _contentTextView.text = [_contentTextView.text substringToIndex:TEXT_MAXLENGTH];
    }
}