I am using the following simple code to add full control to a directory, but it doesn't work.

        String dir_name = @"folder_full_path";
        DirectorySecurity dir_security = Directory.GetAccessControl(dir_name);
        FileSystemAccessRule access_rule = new FileSystemAccessRule(@"AccountName",
            FileSystemRights.FullControl, AccessControlType.Allow);
        dSecurity.AddAccessRule(access_rule);
        Directory.SetAccessControl(dir_name, dir_security);

But this code only set special permissions to the target folder. This code is almost the same as the MSDN sample. I am scratching my head for a reasonable explanation... Hope someone could shed some light on me.

Many thanks.