要从Acumatica REST API中获取联系人/联系人用户信息中的角色数组，您可以使用以下代码示例：

using System;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Threading.Tasks;

namespace AcumaticaAPIExample
{
    class Program
    {
        static async Task Main(string[] args)
        {
            // Acumatica REST API endpoint
            string apiUrl = "https://your-acumatica-url/entity/Default/17.200.001/Contact";

            // Acumatica API credentials
            string username = "your-username";
            string password = "your-password";

            using (HttpClient client = new HttpClient())
            {
                // Set basic authentication header
                string authHeaderValue = Convert.ToBase64String(System.Text.Encoding.ASCII.GetBytes($"{username}:{password}"));
                client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Basic", authHeaderValue);

                // Send GET request to Acumatica REST API
                HttpResponseMessage response = await client.GetAsync(apiUrl);

                // Check if request was successful
                if (response.IsSuccessStatusCode)
                {
                    // Read response content as JSON
                    dynamic jsonData = await response.Content.ReadAsAsync();

                    // Get the "Roles" array from the response
                    dynamic roles = jsonData.value[0].Roles;

                    // Iterate through the roles array
                    foreach (dynamic role in roles)
                    {
                        string roleName = role.Description;
                        Console.WriteLine(roleName);
                    }
                }
                else
                {
                    Console.WriteLine($"Error: {response.StatusCode}");
                }
            }
        }
    }
}

请注意，您需要将https://your-acumatica-url/entity/Default/17.200.001/Contact替换为您实际的Acumatica REST API端点。您还需要将your-username和your-password替换为您的Acumatica API凭据。

此代码示例使用HttpClient发送GET请求来获取联系人/联系人用户信息。然后，它从响应中提取了角色数组并对其进行迭代，打印每个角色的描述。