NSMutableAttributedString *attrString = [[NSMutableAttributedString alloc] initWithString:title];    NSRange range = NSMakeRange(0, [attrString length]);        [attrString beginEditing];    [attrString addAttribute:NSLinkAttributeName value:aURL range:range];        // make the text appear in blue    [attrString addAttribute:NSForegroundColorAttributeName value:[NSColor blueColor] range:range];        // next make the text appear with an underline    [attrString addAttribute:NSUnderlineStyleAttributeName value:[NSNumber numberWithInteger:NSSingleUnderlineStyle] range:range];        // allow truncation    NSMutableParagraphStyle *ps = [[NSParagraphStyle defaultParagraphStyle] mutableCopy];    [ps setLineBreakMode:NSLineBreakByTruncatingTail];    [attrString addAttribute:NSParagraphStyleAttributeName value:ps range:range];    [ps release];        [attrString endEditing];        return [attrString autorelease];

转载自：http://blog.csdn.net/ch_soft/article/details/6877508