C# eBay API DetailLevel

I am developing a C# application which should return all eBay categories available. Unfortunately I am not able to solve an issue about the DetailLevel.

The DetailLevel is part of the request and tells the eBay servers how the response should look.

I have to set the DetailLevel to “ReturnAll”. By following the code samples that are available online I had not success yet.

Here is the code I am using so far:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using EbayGetCategories.ebayAPI;
using System.IO;
using System.ServiceModel;
using System.Xml;
using System.Data.OleDb;

namespace EbayGetCategories
{
    class Program
    {
        static void Main(string[] args)
        {
            int anzahl;
            string endpoint = "https://api.ebay.com/wsapi";
            string callName = "GetCategories";
            string siteId = "0";
            string appId = "YOUR_APPID";     // use your app ID
            string eBayToken = "YOUR_TOKEN";
            string version = "793";
            // Build the request URL
            string requestURL = endpoint
            + "?callname=" + callName
            + "&siteid=" + siteId
            + "&appid=" + appId
            + "&version=" + version
            + "&routing=default";
            // Create the service
            eBayAPIInterfaceClient service = new eBayAPIInterfaceClient("eBayAPI", requestURL);
            // Assign the request URL to the service locator.
            EndpointAddress address = new EndpointAddress(requestURL);
            service.Endpoint.Address = address;
            // Set credentials
            // Make the call to GeteBayOfficialTime
            var detailLevel = new DetailLevelCodeType[1];
            detailLevel[0] = DetailLevelCodeType.ReturnAll;
            GetCategoriesRequestType request = new GetCategoriesRequestType();
            request.WarningLevelSpecified = true;
            request.WarningLevel = WarningLevelCodeType.High;
            request.Version = version;
            request.DetailLevel = detailLevel;
            CustomSecurityHeaderType cred = new CustomSecurityHeaderType();
            cred.eBayAuthToken = eBayToken;
            GetCategoriesResponseType response = service.GetCategories(ref cred, request);
            Console.WriteLine(response.Ack);
            Console.WriteLine(response.CategoryCount);
            Console.ReadKey();
            OleDbConnection con = new OleDbConnection();
            OleDbCommand cmd = new OleDbCommand();
            con.ConnectionString = @"Provider=PervasiveOLEDB;" + @"Data Source=EBAYAPIWARNER;" + @"Location=192.168.0.11;";
            cmd.Connection = con;
            cmd.CommandText = "INSERT INTO 'ebay_categories' VALUES (2,2,'cat',2,'test')";
            try
            {
                con.Open();
                anzahl = cmd.ExecuteNonQuery();
                Console.WriteLine(anzahl);
                con.Close();
            }
            catch(Exception ex)
            {
                Console.WriteLine(ex.Message);
            }
        }
    }
}

The Console shows me the “Ack” values and the “CategoryCount”, which is the number of categories returned by eBay.

For “Ack” I get the value “Success” which is good so far, but CategoryCount always shows me “0”. I have a SOAP Test Tool which gives me the same result if the “DetailLevel” is not set correctly. Could you please help me to solve this issue?