一个Label，某行居中展示。

需求样式如下：

image.png

实现方式，在label上使用富文本展示

NSString *endTime = @"2022 - 02 - 22 13：56";
NSString *endTimeLine = [NSString stringWithFormat:@"到期时间: %@", endTime];
NSString *str = [NSString stringWithFormat:@"现在市场不太友好，动不动就跌几天。主流币都跌百分之五十左右了。\n\n%@",endTimeLine];
if (str.length) {
            UILabel *lab = [[UILabel alloc] init];
            CGFloat labMaxW = 300;
            CGFloat labH = ceilf(lab.font.lineHeight);
            CGFloat labW = ceilf([str boundingRectWithSize:fittingSize options:NSStringDrawingUsesLineFragmentOrigin | NSStringDrawingUsesFontLeading attributes:attr context:nil].size.width);
            if (labW > labMaxW) {
                labW = labMaxW;
                labH = ceilf([str boundingRectWithSize:fittingSize options:NSStringDrawingUsesLineFragmentOrigin | NSStringDrawingUsesFontLeading attributes:attr context:nil].size.height);
            }
            [lab setBounds:CGRectMake(0, 0, labW, labH)];
            NSMutableAttributedString *attriStr = [[NSMutableAttributedString alloc] initWithString:str];
            NSRange range = [str rangeOfString: endTime];
            [attriStr addAttribute:NSForegroundColorAttributeName value:[UIColor redColor] range: range];
            
            NSRange rangeEndTimeLine = [str rangeOfString: endTimeLine];
            NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
            paragraphStyle.alignment = NSTextAlignmentCenter;
            [attriStr addAttribute:NSParagraphStyleAttributeName value:paragraphStyle range: rangeEndTimeLine];
            lab.attributedText = attriStr;
        }