页面启动时添加通知[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(textViewChange:) name:@"UITextViewTextDidChangeNotification" object:self.txtSuggestion];- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text{    NSString *toBeString = [textView.text stringByReplacingCharactersInRange:range withString:text];    if (toBeString.length > kMaxLength && range.length!=1){        textView.text = [toBeString substringToIndex:kMaxLength];        return NO;    }    return YES;}-(void)textViewChange:(NSNotification *)obj{    UITextField *textField = (UITextField *)obj.object;        NSString *toBeString = textField.text;    NSString *lang = [[UIApplication sharedApplication]textInputMode].primaryLanguage; // 键盘输入模式    if ([lang isEqualToString:@"zh-Hans"]) { // 简体中文输入，包括简体拼音，健体五笔，简体手写        UITextRange *selectedRange = [textField markedTextRange];        //获取高亮部分        UITextPosition *position = [textField positionFromPosition:selectedRange.start offset:0];        // 没有高亮选择的字，则对已输入的文字进行字数统计和限制        if (!position) {            if (toBeString.length > kMaxLength) {                textField.text = [toBeString substringToIndex:kMaxLength];            }        }        // 有高亮选择的字符串，则暂不对文字进行统计和限制        else{                    }    }    // 中文输入法以外的直接对其统计限制即可，不考虑其他语种情况    else{        if (toBeString.length > kMaxLength) {            textField.text = [toBeString substringToIndex:kMaxLength];        }      }  }离开页面时[[NSNotificationCenter defaultCenter]removeObserver:self name:@"UITextFieldTextDidChangeNotification"  object:self.txtSuggestion];