问使用C# HttpClient API和postman测试之间的区别？客户端调用适用于邮递员，但不适用于C# httpClient getAsync。

EN

public void createLoan()
{
    string baseCreateLoanUrl = @"https://serverhost/create?key=";
    var strUCDExport = XDocument.Load(@"C:\CreateLoan_testcase.xml");

    using (var client = new HttpClient())
    {
        var content = new StringContent(strUCDExport.ToString(), Encoding.UTF8, Mediatype);
        string createLoanApi = string.Concat(baseCreateLoanUrl, APIKey);

        try
        {
            var response = client.PostAsync(createLoanApi, content).Result;
        }
        catch (Exception ex)
        {
            MessageBox.Show("Error Happened here...");
            throw;
        }

        if (response.IsSuccessStatusCode)
        {
            // Access variables from the returned JSON object
            string responseString = response.Content.ReadAsStringAsync().Result;
            JObject jObj = JObject.Parse(responseString);

            if (jObj.SelectToken("failure") == null)
            {
                // First get the authToken
                string LoanID = jObj["loanStatus"]["id"].ToString();
                MessageBox.Show("Loan ID: " + LoanID);
            }
            else
            {
                string getTokenErrorMsg = string.Empty;

                JArray errorOjbs = (JArray) jObj["failure"]["errors"];
                foreach (var errorObj in errorOjbs)
                {
                    getTokenErrorMsg += errorObj["message"].ToString() + Environment.NewLine;
                }
                getTokenErrorMsg.Dump();
            }
        }
    }