string str = ",/upload/2008-10-19/标志.psd@238637,/upload/2008-10-19/标志0.psd@277244,/upload/2008-10-19/jianjie.psd@716459,/upload/2008-10-19/biaozhi.psd@222304";
        Regex reg=new Regex("(/upload/\\d+-\\d+-\\d+/[^@]+)@\\d+");
        MatchCollection mat=reg.Matches(str);
怎么通过反向引用获取(/upload/\\d+-\\d+-\\d+/[^@]+)所匹配的内容呢