ios - 调整文字下划线前导

Question

我想将一行文本上的下划线向下移动（远离文本），即 调整领先。但这不起作用：

NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
paragraphStyle.lineSpacing = 5.0f;

 NSMutableAttributedString *string = [[NSMutableAttributedString alloc] initWithString:@"Something"];
 [string addAttribute:NSUnderlineStyleAttributeName value:[NSNumber numberWithInt:NSUnderlineStyleSingle] range:NSMakeRange(0, string.length)];
 [string addAttribute:NSParagraphStyleAttributeName value:paragraphStyle range:NSMakeRange(0, string.length)];

可能吗？