參考:http://blog.sina.com.cn/s/blog_a3dbd02a01012ixk.html
參考2:http://www.tuicool.com/articles/Fvqia2
NSMutableAttributedString *attrString =[[NSMutableAttributedStringalloc]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:NSForegroundColorAttributeNamevalue:[NSColorblueColor] range:range];
// next make the text appear with anunderline
[attrString addAttribute:NSUnderlineStyleAttributeNamevalue:[NSNumbernumberWithInteger:NSSingleUnderlineStyle]range:range];
// allow truncation
NSMutableParagraphStyle *ps = [[NSParagraphStyledefaultParagraphStyle] mutableCopy];
[ps setLineBreakMode:NSLineBreakByTruncatingTail];
[attrString addAttribute:NSParagraphStyleAttributeName value:ps range:range];
[ps release];
[attrString endEditing];