问提供了一个无效的请求URI。请求URI必须是绝对URI，或者必须设置BaseAddress。尝试使用webservice

EN

public class Customer
{
    public int id { get; set; }
    public string id_default_group { get; set; }
    public string id_lang { get; set; }
    public string newsletter_date_add { get; set; }
    public string ip_registration_newsletter { get; set; }
    public string last_passwd_gen { get; set; }
    public string secure_key { get; set; }
    public string deleted { get; set; }
    public string passwd { get; set; }
    public string lastname { get; set; }
    public string firstname { get; set; }
    public string email { get; set; }
    public string id_gender { get; set; }
    public string birthday { get; set; }
    public string newsletter { get; set; }
    public string optin { get; set; }
    public string website { get; set; }
    public string company { get; set; }
    public string siret { get; set; }
    public string ape { get; set; }
    public string outstanding_allow_amount { get; set; }
    public string show_public_prices { get; set; }
    public string id_risk { get; set; }
    public string max_payment_days { get; set; }
    public string active { get; set; }
    public string note { get; set; }
    public string is_guest { get; set; }
    public string id_shop { get; set; }
    public string id_shop_group { get; set; }
    public string date_add { get; set; }
    public string date_upd { get; set; }
    public string reset_password_token { get; set; }
    public string reset_password_validity { get; set; }

}

class Program
{

    static void ShowProduct(Customer customer)
    {
        Console.WriteLine($"Email: {customer.email}\tFirst Name: {customer.firstname}");
    }

    static async Task<Uri> CreateCustomerAsync(Customer customer)
    {
        HttpClient client = new HttpClient();
        HttpResponseMessage response = await client.PostAsJsonAsync("api/customers/1?output_format=JSON", customer);
        response.EnsureSuccessStatusCode();

        // return URI of the created resource.
        return response.Headers.Location;
    }
    static void Main()
    {
        RunAsync().Wait();
    }
    static async Task RunAsync()
    {
        NetworkCredential hd = new NetworkCredential("INHFTLZLMLP1TUTJE7JL9LETCCEW63FN", "");
        HttpClientHandler handler = new HttpClientHandler {Credentials = hd };
        HttpClient client = new HttpClient(handler);

        client.BaseAddress = new Uri("http://localhost:8080/newprestashop/");
        client.DefaultRequestHeaders.Accept.Clear();
        client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));

            try
            {

                Customer customer = new Customer();
                var url = await CreateCustomerAsync(customer);
                // Get the product
                customer = await GetProductAsync(url.PathAndQuery);
                ShowProduct(customer);


            }
            catch (Exception e)
            {
                Console.WriteLine(e.Message);
            }

            Console.ReadLine();
        }

    static async Task<Customer> GetProductAsync(string path)
    {
        Customer customer = null;
        HttpClient client = new HttpClient();
        HttpResponseMessage response = await client.GetAsync(path);
        if (response.IsSuccessStatusCode)
        {
            customer = await response.Content.ReadAsAsync<Customer>();
        }
        return customer;
    }

}