NSMutableAttributedString 的使用方法，设置格式

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];