iOS之label添加下劃線

             UILabel *linkLabel = [[UILabel alloc]init];

            linkLabel.frame = CGRectMake(10, introduceLabel.frame.origin.y +introduceLabel.frame.size.height +10, [UIScreen mainScreen].bounds.size.width - 20, 20);

            NSMutableAttributedString *content = [[NSMutableAttributedString alloc]initWithString:[NSString stringWithFormat:@"%@",data[@"skipLinkText"]]];

            NSRange contentRange = {0,[content length]};

            [content addAttribute:NSUnderlineStyleAttributeName value:[NSNumber numberWithInteger:NSUnderlineStyleSingle] range:contentRange];

            linkLabel.attributedText = content;

            linkLabel.textColor = [UIColor blueColor];

            linkLabel.font = [UIFont systemFontOfSize:10];

            [linkLabel setLineBreakMode:NSLineBreakByWordWrapping];

            linkLabel.numberOfLines = 2;

            CGSize maximumLabelSize = CGSizeMake([UIScreen mainScreen].bounds.size.width - 20, 9999);

            CGSize expectSize = [linkLabel sizeThatFits:maximumLabelSize];

            linkLabel.frame = CGRectMake(10, introduceLabel.frame.origin.y +introduceLabel.frame.size.height +10, expectSize.width, expectSize.height);

            [self.infoScrollView addSubview:linkLabel];