给属性字符串添加下划线

 NSString *text = @"Privacy Policy.";

    NSMutableAttributedString * attributedText = [[NSMutableAttributedString alloc] initWithString: text];

    NSRange range = NSMakeRange(0, [attributedText length]);

    [attributedText beginEditing];

       // next make the text appear with an underline

    NSRange underLineRange = range;

    range.length -= 1;

    [attributedText addAttribute: NSUnderlineStyleAttributeName value:[NSNumber numberWithInt:NSSingleUnderlineStyle] range:underLineRange];

    [attributedText addAttribute:NSFontAttributeName value:PRDefaultFontWithSize(NO, 12) range:range];

    [attributedText addAttribute:NSForegroundColorAttributeName value:[NSColor colorWithDeviceRed:237/255.0 green:187/255.0 blue:112/255.0 alpha:1] range:underLineRange];

    [attributedText addAttribute:NSForegroundColorAttributeName value:[NSColor colorWithDeviceRed:128/255.0 green:128/255.0 blue:128/255.0 alpha:1]range:NSMakeRange([attributedText length]-1, 1)];

    

    [attributedText endEditing];