#pragma mark - UITextViewDelegate- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text{    UITextRange *selectedRange1 = [textView markedTextRange];    //获取高亮部分    UITextPosition *pos = [textView positionFromPosition:selectedRange1.start offset:0];    //获取高亮部分内容    //NSString * selectedtext = [textView textInRange:selectedRange];        //如果有高亮且当前字数开始位置小于最大限制时允许输入    if (selectedRange1 && pos) {        NSInteger startOffset = [textView offsetFromPosition:textView.beginningOfDocument toPosition:selectedRange1.start];        NSInteger endOffset = [textView offsetFromPosition:textView.beginningOfDocument toPosition:selectedRange1.end];        NSRange offsetRange = NSMakeRange(startOffset, endOffset - startOffset);                if (offsetRange.location < MAX_LIMIT_NUMS) {            return YES;        }        else        {            return NO;        }    }            NSString *comcatstr = [textView.text stringByReplacingCharactersInRange:range withString:text];        //    NSInteger caninputlen = MAX_LIMIT_NUMS - comcatstr.length;    NSInteger caninputlen = MAX_LIMIT_NUMS -  [comcatstr getStringLengthIfIsEmojiLengthAsOne];            if (caninputlen >= 0)    {        return YES;    }    else    {        //        NSInteger len = text.length + caninputlen;        NSInteger len = [text getStringLengthIfIsEmojiLengthAsOne] + caninputlen;                //防止当text.length + caninputlen < 0时，使得rg.length为一个非法最大正数出错        NSRange rg = {0,MAX(len,0)};                if (rg.length > 0)        {            NSString *s = @"";            //判断是否只普通的字符或asc码(对于中文和表情返回NO)            BOOL asc = [text canBeConvertedToEncoding:NSASCIIStringEncoding];            if (asc) {                s = [text substringWithRange:rg];//因为是ascii码直接取就可以了不会错            }            else            {                __block NSInteger idx = 0;                __block NSString  *trimString = @"";//截取出的字串                //使用字符串遍历，这个方法能准确知道每个emoji是占一个unicode还是两个                [text enumerateSubstringsInRange:NSMakeRange(0, [text length])                                         options:NSStringEnumerationByComposedCharacterSequences                                      usingBlock: ^(NSString* substring, NSRange substringRange, NSRange enclosingRange, BOOL* stop) {                                          //                                          NSInteger steplen = substring.length;                                          NSInteger steplen = [substring getStringLengthIfIsEmojiLengthAsOne];                                                                                    if (idx >= rg.length) {                                              *stop = YES; //取出所需要就break，提高效率                                              return ;                                          }                                                                                    trimString = [trimString stringByAppendingString:substring];                                                                                    idx = idx + steplen;                                      }];                                s = trimString;            }                                    __block BOOL hasAttachment = NO;            [textView.attributedText enumerateAttributesInRange:NSMakeRange(0, textView.attributedText.length) options:NSAttributedStringEnumerationReverse usingBlock:^(NSDictionary *attrs, NSRange range, BOOL *stop) {                                if(attrs[@"NSAttachment"])                {                    *stop  = YES;                    hasAttachment = YES;                }            }];                        if (textView.text.length > MAX_LIMIT_NUMS) {                [self showHudTipStr:@"输入已达上限"];                if (hasAttachment) {                                        [textView.attributedText attributedSubstringFromRange:NSMakeRange(0, MAX_LIMIT_NUMS)];                                                        } else {                                        //rang是指从当前光标处进行替换处理(注意如果执行此句后面返回的是YES会触发didchange事件)                    [textView setText:[textView.text stringByReplacingCharactersInRange:range withString:s]];                }            }                                    //既然是超出部分截取了，哪一定是最大限制了。                        self.inputNumberTipsLabel.text = [NSString stringWithFormat:@"%d/%ld",0,(long)MAX_LIMIT_NUMS];        }        if (textView.text.length >= MAX_LIMIT_NUMS) {            [self showHudTipStr:@"输入已达上限"];        }        return NO;    }    }- (void)textViewDidChange:(UITextView *)textView{    // 占位文本显示与否    //    _submitEvaluationBtn.enabled = self.evaluationTextView.hasText;        UITextRange *selectedRange1 = [textView markedTextRange];    //获取高亮部分    UITextPosition *pos = [textView positionFromPosition:selectedRange1.start offset:0];        //如果在变化中是高亮部分在变，就不要计算字符了    if (selectedRange1 && pos) {        return;    }        NSString  *nsTextContent = textView.text;    //    NSInteger existTextNum = nsTextContent.length;    NSInteger existTextNum = [nsTextContent getStringLengthIfIsEmojiLengthAsOne];            if (existTextNum >= MAX_LIMIT_NUMS)    {        [self showHudTipStr:@"输入已达上限"];        __block BOOL hasAttachment = NO;        [textView.attributedText enumerateAttributesInRange:NSMakeRange(0, textView.attributedText.length) options:NSAttributedStringEnumerationReverse usingBlock:^(NSDictionary *attrs, NSRange range, BOOL *stop) {                        if(attrs[@"NSAttachment"])            {                *stop  = YES;                hasAttachment = YES;            }        }];                if (hasAttachment) {                        textView.attributedText = [textView.attributedText attributedSubstringFromRange:NSMakeRange(0, MAX_LIMIT_NUMS + [textView.text emojiCount])];                    } else {            //截取到最大位置的字符(由于超出截部分在should时被处理了所在这里这了提高效率不再判断)            NSString *s = [nsTextContent substringToIndex:(MAX_LIMIT_NUMS + [textView.text emojiCount])];                        [textView setText:s];        }    }        //不让显示负数 口口日        self.inputNumberTipsLabel.text = [NSString stringWithFormat:@"%tu/%tu",MAX(0,MAX_LIMIT_NUMS - existTextNum),MAX_LIMIT_NUMS];}