COnvertion issue

Hello,

you need to change your json response, you have sponse name SubSurveyNumber and one property of response also with same name as "SubSurveyNumber" so please change that and create one class with below property then it will work,

  public class SubSurveyDetails
    {
        public string DistrictLG_Code { get; set; }
        public string SubDistrict { get; set; }
        public string SubSurveyNumber { get; set; }
        public string SurveyNumber { get; set; }
        public string VillageCode { get; set; }

    }

List response = JavaScriptSerializer().Deserialize>(result);

Can you please check GetSubsurveyno class.... does it has all the properties which the JSON tag has? 

Json :

{
  "SubSurveyNumber": [
    {
      "DistrictLG_Code": "Token is Expired!",
      "SubDistrict": "Get New Token.",
      "VillageCode": "",
      "SurveyNumber": "",
      "SubSurveyNumber": ""
    }
  ]
}

Your class should be something like this 

public class SubSurveyNumber {
 public string DistrictLG_Code { get; set; }
 public string SubDistrict { get; set; }
 public string VillageCode { get; set; }
 public string SurveyNumber { get; set; }
 public string SubSurveyNumber { get; set; }

}
public class Application {
 public IList SubSurveyNumber { get; set; }

}