C#正则表达式分组使用

            string s = "dfasfdasfdsa*fdasfdsafdsa";
             s = "转发:dfasfdasfdsa*fdasfdsafdsa";
             //s = "转发:***dfasfdasfdsa*fdasfdsafdsa";
             //s = "转发: dfasfdasfdsa*fdasfdsafdsa";
             //s = "转发: * * * dfasfdasfdsa*fdasfdsafdsa";

             MatchCollection mc = Regex.Matches(s, @"(转发:)*[\s|*]*(?<a>\S+)");
             foreach (Match m in mc)
             {
                 string s2 = m.Groups["a"].Value;
                 //s2 = dfasfdasfdsa*fdasfdsafdsa
             }     

分组中我们使用(?<a>\S+)表示一组