PayPal API Http調用問題

Question

我已經為用戶集成了一個選項，通過PayPal在我正在創建的網上商店進行在線購物。 當我開始收到此錯誤時突然出現問題：

You must write ContentLength bytes to the request stream before calling [Begin]GetResponse. 

Http調用的代碼如下：

   public string HttpCall(string NvpRequest)
        {
            string url = pEndPointURL;

            string strPost = NvpRequest + "&" + buildCredentialsNVPString();
            strPost = strPost + "&BUTTONSOURCE=" + HttpUtility.UrlEncode(BNCode);

            HttpWebRequest objRequest = (HttpWebRequest)WebRequest.Create(url);
            objRequest.Timeout = Timeout;
            objRequest.Method = "POST";
            objRequest.ContentLength = strPost.Length;

            try
            {
                using (StreamWriter myWriter = new StreamWriter(objRequest.GetRequestStream()))
                {
                    myWriter.Write(strPost.ToString());
                }
            }
            catch (Exception e)
            {

            }

            //Retrieve the Response returned from the NVP API call to PayPal. 
            HttpWebResponse objResponse = (HttpWebResponse)objRequest.GetResponse(); // this is the line where the exception occurs...
            string result;
            using (StreamReader sr = new StreamReader(objResponse.GetResponseStream()))
            {
                result = sr.ReadToEnd();
            }

            return result;
        }

有人可以幫我解決這個問題嗎？ 它一天前工作正常，現在它給我這個錯誤？

Answer 1

好的，如果有人有興趣，我可以通過在創建Web請求之前添加以下行來修復錯誤（我能夠通過像這樣下載到Tls12來修復它）：

`ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12`;

干杯:-)

編輯試試這個：

 public string HttpCall(string NvpRequest)
    {
        string url = pEndPointURL;

        string strPost = NvpRequest + "&" + buildCredentialsNVPString();
        strPost = strPost + "&BUTTONSOURCE=" + HttpUtility.UrlEncode(BNCode);
        ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls;
        // Try using Tls11 if it doesnt works for you with Tls
        HttpWebRequest objRequest = (HttpWebRequest)WebRequest.Create(url);
        objRequest.Timeout = Timeout;
        objRequest.Method = WebRequestMethods.Http.Post;
        objRequest.ContentLength = strPost.Length;
        try
        {

            using (StreamWriter myWriter = new StreamWriter(objRequest.GetRequestStream()))
            {
                myWriter.Write(strPost.ToString());
            }
        }
        catch (Exception e)
        {

        }

        //Retrieve the Response returned from the NVP API call to PayPal. 
        HttpWebResponse objResponse = (HttpWebResponse)objRequest.GetResponse();
        string result;
        using (StreamReader sr = new StreamReader(objResponse.GetResponseStream()))
        {
            result = sr.ReadToEnd();
        }

        return result;
    }

Answer 2

public string HttpCall(string NvpRequest) //CallNvpServer
{
    string url = pendpointurl;

    //To Add the credentials from the profile
    string strPost = NvpRequest + "&" + buildCredentialsNVPString();
    strPost = strPost + "&BUTTONSOURCE=" + HttpUtility.UrlEncode( BNCode );

    HttpWebRequest objRequest = (HttpWebRequest)WebRequest.Create(url);
    objRequest.Timeout = Timeout;
    objRequest.Method = "POST";
    objRequest.ContentLength = strPost.Length;

    try
    {
        using (StreamWriter myWriter = new StreamWriter(objRequest.GetRequestStream()))
        {
            myWriter.Write(strPost);
        }
    }
    catch (Exception e)
    {
        /*
        if (log.IsFatalEnabled)
        {
            log.Fatal(e.Message, this);
        }*/
    }

    //Retrieve the Response returned from the NVP API call to PayPal


    HttpWebResponse objResponse = (HttpWebResponse)objRequest.GetResponse();
    string result;
    using (StreamReader sr = new StreamReader(objResponse.GetResponseStream()))
    {
        result = sr.ReadToEnd();
    }

    //Logging the response of the transaction
    /* if (log.IsInfoEnabled)
     {
         log.Info("Result :" +
                   " Elapsed Time : " + (DateTime.Now - startDate).Milliseconds + " ms" +
                  result);
     }
     */
    return result;
}

Answer 3

經過幾個小時的浪費，結果證明是Tls協議版本。

ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;