Update submitted Perforce changelist description by P4.net api

Firstly download the p4.net sdk from Perforce official site's download page.

It's a .zip file, extract it to disk and you'll find a README.txt for how to create a .net application to use the API.

And here is the C# code to update a submitted changelist's description:

 using Perforce.P4;

 namespace ModifyP4CLDescription
 {
     class Program
     {
         static void Main(string[] args)
         {
             string uri = "my_perforce_server:1666";
             string user = "my_user_name";
             string ws_client = "my_work_space_name";

             Server server = new Server(new ServerAddress(uri));
             Repository rep = new Repository(server);
             Connection con = rep.Connection;

             con.UserName = user;
             con.Client = new Client();
             con.Client.Name = ws_client;

             con.Connect(null);

             Changelist c = rep.GetChangelist();
             string newDiscription = c.Description + "modify my description";
             c.Description = newDiscription;
             ChangeCmdOptions opts = new ChangeCmdOptions(ChangeCmdFlags.Update);
             c = rep.UpdateChangelist(c, opts);
29         }
     }
 }