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

             }