正则怎么获得21456688754

Question

http://item.taobao.com/item.htm?id=21456688754&ali_refid=a3_420763_1007:1102249745:7:4043f4c103d9bc6af0a150eaaa84293d:809ab74692c8b2532811f1c84fbbe72b&ali_trackid=1_809ab74692c8b2532811f1c84fbbe72b正则

Answer 1

public static void Main()
        {
            string str = @"http://item.taobao.com/item.htm?id=21456688754&ali_refid=a3_420763_1007:1102249745:7:4043f4c103d9bc6af0a150eaaa84293d:809ab74692c8b2532811f1c84fbbe72b&ali_trackid=1_809ab74692c8b2532811f1c84fbbe72b";
            Regex reg = new Regex(@"(?<=id=)(\d+)");
            if (reg.IsMatch(str))
            {
                Match m = reg.Match(str);
                Console.WriteLine(m.Value);
            }
            Console.Read();
        }输出：
21456688754

Answer 2

string s = "http://item.taobao.com/item.htm?id=21456688754&ali_refid=a3_420763_1007:1102249745:7:4043f4c103d9bc6af0a150eaaa84293d:809ab74692c8b2532811f1c84fbbe72b&ali_trackid=1_809ab74692c8b2532811f1c84fbbe72b";
string id = HttpUtility.ParseQueryString(new Uri(s).Query)["id"];
Response.Write(id);