iOS UILabel自定义行间距

NSString *hintStr = @"输入材料标题搜索材料\n注:可根据材料序号直接搜索, 如TPO23";

CGSize size = [toolset returnTextStringSizeWithString:hintStr withBoundSize:CGSizeMake(Main_Screen_Width - 72, MAXFLOAT) withFont:FZHei(15)];

self.mHintLabelLayoutH.constant = size.height + 20;

[self.mHitLabel setNeedsLayout];

NSMutableAttributedString *prefixAttr = [[NSMutableAttributedString alloc] initWithString:hintStr];

[prefixAttr addAttribute:NSFontAttributeName value:FZHei(17) range:NSMakeRange(0, hintStr.length)];

[prefixAttr addAttribute:NSForegroundColorAttributeName value:ColorHui range:NSMakeRange(0, hintStr.length)];

[prefixAttr addAttribute:NSForegroundColorAttributeName value:HexRGB(0xc0c0c0) range:NSMakeRange(11, 21)];

[prefixAttr addAttribute:NSFontAttributeName value:FZHei(13) range:NSMakeRange(11, 21)];

NSMutableParagraphStyle *paragraphString = [[NSMutableParagraphStyle alloc] init];

[paragraphString setLineSpacing:8];    //设置行间距

[prefixAttr addAttribute:NSParagraphStyleAttributeName value:paragraphString range:NSMakeRange(0, hintStr.length)];

self.mHitLabel.attributedText = prefixAttr;