string pattern = @"(?is)(?<=https?://[^/]+/)(?!abc/)";

解决方案 »

  1.   

    str=Regex.Replace(str,@"(?i)(?<=\.com/)((?!abc\.)[^/])+",m=>m.Value.ToUpper()=="ABC"?"":"ABC/"+m.Value);
      

  2.   

     string format =  @"https://www.(\w+).com/ABC/(.+)?";
                Regex g = new Regex(format);
                string mystr = @"https://www.baidu.com/AB/a.aspx";
                if (g.IsMatch(mystr))
                {
                    Console.WriteLine("yes");
                }
                else
                {
                    string t = @"https://www.(\w+).com";
                    Regex g2 = new Regex(t);
                    string url=  g2.Match(mystr).Groups[0].Value;
                    Console.WriteLine("no");
                    Console.WriteLine(url);                int index = mystr.IndexOf(url)+url.Length;
                    string newstr= mystr.Insert(index, @"/ABC");                Console.WriteLine(newstr);
                }
                Console.Read();
      

  3.   

    void Main()
    {
    string[] ary= {
    "https://www.domain.com/ABC/edit.aspx&..",
    "https://www.domain.com/user/abc.aspx&... ",
    "https://www.domain.com/ABC.html"
     };
    foreach(var str in ary)
    Console.WriteLine("{0}\t{1}",str,Regex.Replace(str,@"(?i)(?<=\.com/)[^/]+(?=/|$)",m=>m.Value.ToUpper()=="ABC"?"ABC":"ABC/"+m.Value));
    }
      

  4.   

    Result:https://www.domain.com/ABC/edit.aspx&.. https://www.domain.com/ABC/edit.aspx&..
    https://www.domain.com/user/abc.aspx&...  https://www.domain.com/ABC/user/abc.aspx&... 
    https://www.domain.com/ABC.html https://www.domain.com/ABC/ABC.html
      

  5.   


     List<string> list = new List<string>();
                list.Add("https://www.domain.com/ABC/edit.aspx&... ");
                list.Add("https://www.domain.com/user/abc.aspx& ");
                list.Add("https://www.domain.com/ABC.html ");
                Regex reg = new Regex(@"(?is)(https?://([^./]*\.)+com/)(?!ABC/)");
                foreach (string s in list)
            {
                    Console.WriteLine(reg.Replace(s,"$1ABC/"));
            }
    /****结果****https://www.domain.com/AB
    https://www.domain.com/AB
    https://www.domain.com/AB
    请按任意键继续. . .****结果****/