C# NVPCodec类代码示例

        public PayPalResponse ECGetExpressCheckout(string token)
        {
            NVPCallerServices caller = new NVPCallerServices();
            IAPIProfile profile = getProfile();
            caller.APIProfile = profile;

            NVPCodec encoder = new NVPCodec();
            encoder["VERSION"] = "84.0";
            encoder["METHOD"] = "GetExpressCheckoutDetails";

            // Add request-specific fields to the request.
            encoder["TOKEN"] = token; // Pass the token returned in SetExpressCheckout.

            // Execute the API operation and obtain the response.
            string pStrrequestforNvp = encoder.Encode();
            string pStresponsenvp = caller.Call(pStrrequestforNvp);

            NVPCodec decoder = new NVPCodec();
            decoder.Decode(pStresponsenvp);
            PayPalResponse response = new PayPalResponse {
                token = (decoder["TOKEN"] != null) ? decoder["TOKEN"] : "",
                acknowledgement = decoder["ACK"],
                first = decoder["FIRSTNAME"],
                last = decoder["LASTNAME"],
                email = decoder["EMAIL"],
                amount = decoder["PAYMENTREQUEST_0_AMT"],
                payerID = decoder["PAYERID"]
            };
            return response;
        }

    public bool DoCheckoutPayment(string finalPaymentAmount, string token, string PayerID, ref NVPCodec decoder, ref string retMsg)
    {
        if (bSandbox)
        {
            pEndPointURL = pEndPointURL_SB;
        }

        NVPCodec encoder = new NVPCodec();
        encoder["METHOD"] = "DoExpressCheckoutPayment";
        encoder["TOKEN"] = token;
        encoder["PAYERID"] = PayerID;
        encoder["PAYMENTREQUEST_0_AMT"] = finalPaymentAmount;
        encoder["PAYMENTREQUEST_0_CURRENCYCODE"] = "USD";
        encoder["PAYMENTREQUEST_0_PAYMENTACTION"] = "Sale";

        string pStrrequestforNvp = encoder.Encode();
        string pStresponsenvp = HttpCall(pStrrequestforNvp);

        decoder = new NVPCodec();
        decoder.Decode(pStresponsenvp);

        string strAck = decoder["ACK"].ToLower();
        if (strAck != null && (strAck == "success" || strAck == "successwithwarning"))
        {
            return true;
        }
        else
        {
            retMsg = "ErrorCode=" + decoder["L_ERRORCODE0"] + "&" +
                "Desc=" + decoder["L_SHORTMESSAGE0"] + "&" +
                "Desc2=" + decoder["L_LONGMESSAGE0"];

            return false;
        }
    }

        public string GetTransactionDetailsCode(string transactionID)
        {
            NVPCallerServices caller = new NVPCallerServices();
            IAPIProfile profile = ProfileFactory.createSignatureAPIProfile();
            /*
             WARNING: Do not embed plaintext credentials in your application code.
             Doing so is insecure and against best practices.
             Your API credentials must be handled securely. Please consider
             encrypting them for use in any production environment, and ensure
             that only authorized individuals may view or modify them.
             */

            // Set up your API credentials, PayPal end point, API operation and version.
            profile.APIUsername = "sdk-three_api1.sdk.com";
            profile.APIPassword = "QFZCWN5HZM8VBG7Q";
            profile.APISignature = "AVGidzoSQiGWu.lGj3z15HLczXaaAcK6imHawrjefqgclVwBe8imgCHZ";
            profile.Environment="sandbox";
            caller.APIProfile = profile;

            NVPCodec encoder = new NVPCodec();
            encoder["VERSION"] =  "51.0";
            encoder["METHOD"] =  "GetTransactionDetails";

            // Add request-specific fields to the request.
            encoder["TRANSACTIONID"] =  transactionID;

            // Execute the API operation and obtain the response.
            string pStrrequestforNvp= encoder.Encode();
            string pStresponsenvp=caller.Call(pStrrequestforNvp);

            NVPCodec decoder = new NVPCodec();
            decoder.Decode(pStresponsenvp);
            return decoder["ACK"];
        }

        public string GetBalanceCode()
        {
            NVPCallerServices caller = new NVPCallerServices();
            IAPIProfile profile = ProfileFactory.createSignatureAPIProfile();
            /*
             WARNING: Do not embed plaintext credentials in your application code.
             Doing so is insecure and against best practices.
             Your API credentials must be handled securely. Please consider
             encrypting them for use in any production environment, and ensure
             that only authorized individuals may view or modify them.
             */
            profile.APIUsername = "sdk-three_api1.sdk.com";
            profile.APIPassword = "QFZCWN5HZM8VBG7Q";
            profile.APISignature = "AVGidzoSQiGWu.lGj3z15HLczXaaAcK6imHawrjefqgclVwBe8imgCHZ";
            profile.Environment="sandbox";
            caller.APIProfile = profile;

            NVPCodec encoder = new NVPCodec();
            encoder["VERSION"] =  "51.0";
            encoder["METHOD"] =  "GetBalance";
            string pStrrequestforNvp= encoder.Encode();
            string pStresponsenvp=caller.Call(pStrrequestforNvp);

            NVPCodec decoder = new NVPCodec();
            decoder.Decode(pStresponsenvp);
            return decoder["ACK"];
        }

        public string ECSetExpressCheckout_PayLaterCode(string returnURL,string cancelURL,string amount,string paymentType,string currencyCode)
        {
            NVPCallerServices caller = new NVPCallerServices();
            IAPIProfile profile = ProfileFactory.createSignatureAPIProfile();
            /*
             WARNING: Do not embed plaintext credentials in your application code.
             Doing so is insecure and against best practices.
             Your API credentials must be handled securely. Please consider
             encrypting them for use in any production environment, and ensure
             that only authorized individuals may view or modify them.
             */
            profile.APIUsername = "sdk-three_api1.sdk.com";
            profile.APIPassword = "QFZCWN5HZM8VBG7Q";
            profile.APISignature = "AVGidzoSQiGWu.lGj3z15HLczXaaAcK6imHawrjefqgclVwBe8imgCHZ";
            profile.Environment="sandbox";
            caller.APIProfile = profile;

            NVPCodec encoder = new NVPCodec();
            encoder["VERSION"] =  "51.0";
            encoder["METHOD"] =  "SetExpressCheckout";
            encoder["RETURNURL"] =  returnURL;
            encoder["CANCELURL"] =  cancelURL;
            encoder["AMT"] =  amount;
            encoder["PAYMENTACTION"] =  paymentType;
            encoder["CURRENCYCODE"] =  currencyCode;
            encoder["L_PROMOCODE0"] = "101";
            string pStrrequestforNvp= encoder.Encode();
            string pStresponsenvp=caller.Call(pStrrequestforNvp);

            NVPCodec decoder = new NVPCodec();
            decoder.Decode(pStresponsenvp);
            return decoder["ACK"];
        }

 protected void Page_Load(object sender, EventArgs e)
 {
     try
     {
         if (Request.QueryString["Code"].ToLower() == "Cancel".ToLower())
         {
             return;
         }
         else if (Request.QueryString["Code"].ToLower() == "Sucess".ToLower())
         {
             lblAppName.InnerHtml = Session["AppName"].ToString();
             imgApp.Src = Session["AppIcon"].ToString();
             lblValidationCode.Text = Session.SessionID;
             return;
         }
         else if (Request.QueryString["Code"].ToLower() == "Error".ToLower())
         {
             lblAppName.InnerHtml = Session["AppIcon"].ToString();
             imgApp.Src = Session["AppIcon"].ToString();
             lblValidationCode.Text = Session["errorresult"].ToString();
             return;
         }
         Session["AppName"] = Request.QueryString["AppName"].ToString();
         Session["AppIcon"] = Request.QueryString["AppIcon"].ToString();
         string url = Request.Url.Scheme + "://" + Request.Url.Host + ":" + Request.Url.Port + "";
         string cancelURL = url + ResolveUrl("paypal.aspx") + "?Code=Cancel";
         string returnURL = url + ResolveUrl("paypal.aspx") + "?Code=Sucess";
         ECSetExpressCheckout objset = new ECSetExpressCheckout();
         NVPCodec decoder = new NVPCodec();
         decoder = objset.ECSetExpressCheckoutCode(returnURL, Request.QueryString["AppName"].ToString(), System.Configuration.ConfigurationManager.AppSettings["AppCode"].ToString(), cancelURL, Request.QueryString["Price"].ToString(), "Sale", Request.QueryString["Currency"].ToString());
         string strAck = decoder["ACK"];
         if (strAck != null && (strAck == "Success" || strAck == "SuccessWithWarning"))
         {
             Session["TOKEN"] = decoder["TOKEN"];
             string host1 = "www." + ASPDotNetSamples.AspNet.Constants.ENVIRONMENT + ".paypal.com";
             //
             string ECURL = string.Empty;
             if (System.Configuration.ConfigurationManager.AppSettings["ENVIRONMENT"].ToString() == "T")
             {
                 ECURL = "https://" + host1 + "/cgi-bin/webscr?cmd=_express-checkout" + "&token=" + decoder["TOKEN"];
             }
             else
             {
                 ECURL = "https://www.paypal.com/webscr?cmd=_express-checkout" + "&token=" + decoder["TOKEN"];
             }
             Response.Redirect(ECURL, false);
         }
         else
         {
             Session["errorresult"] = decoder;
             string pStrResQue = "API=" + ASPDotNetSamples.AspNet.Util.BuildResponse(decoder, "Set", "");
             Response.Redirect("paypal.aspx?Code=Error");
         }
     }
     catch (Exception ex)
     {
         Session["errorresult"] = "API=" + ex.Message;
         Response.Redirect("paypal.aspx?Code=Error");
     }
 }

    public NVPCodec CancelAuthorization(string transactionID, string note)
    {
        NVPCallerServices caller = new NVPCallerServices();
        IAPIProfile profile = ProfileFactory.createSignatureAPIProfile();
        /*
         WARNING: Do not embed plaintext credentials in your application code.
         Doing so is insecure and against best practices.
         Your API credentials must be handled securely. Please consider
         encrypting them for use in any production environment, and ensure
         that only authorized individuals may view or modify them.
         */

        // Set up your API credentials, PayPal end point, API operation and version.
        caller.APIProfile = profile;

        NVPCodec encoder = new NVPCodec();
        encoder["VERSION"] = "51.0";
        encoder["METHOD"] = "DoVoid";

        // Add request-specific fields to the request.
        encoder["AUTHORIZATIONID"] = transactionID;
        encoder["NOTE"] = note;
        encoder["TRXTYPE"] = "V";

        // Execute the API operation and obtain the response.
        string pStrrequestforNvp = encoder.Encode();
        string pStresponsenvp = caller.Call(pStrrequestforNvp);

        NVPCodec decoder = new NVPCodec();
        return decoder;
    }

 public bool ShortcutExpressCheckout(string amt, ref string token, ref string 
retMsg) 
 { if (bSandbox)
 { 
 pEndPointURL = pEndPointURL_SB; 
 host = host_SB; 
 } 
 
 string returnURL = "http://localhost:1234/Checkout/CheckoutReview.aspx"; 
 string cancelURL = "http://localhost:1234/Checkout/CheckoutCancel.aspx"; 
 
 NVPCodec encoder = new NVPCodec(); 
 encoder["METHOD"] = "SetExpressCheckout"; 
 encoder["RETURNURL"] = returnURL; 
 encoder["CANCELURL"] = cancelURL; 
 encoder["BRANDNAME"] = "Wingtip Toys Sample Application"; 
 encoder["PAYMENTREQUEST_0_AMT"] = amt; 
 encoder["PAYMENTREQUEST_0_ITEMAMT"] = amt; 
 encoder["PAYMENTREQUEST_0_PAYMENTACTION"] = "Sale"; 
 encoder["PAYMENTREQUEST_0_CURRENCYCODE"] = "USD"; 
 
 // Get the Shopping Cart Products 
 using (ClassiqWheels.Logic.ShoppingCartActions myCartOrders = new
ClassiqWheels.Logic.ShoppingCartActions()) 
 { 
 List<CartItem> myOrderList = myCartOrders.GetCartItems(); 
 
 for (int i = 0; i < myOrderList.Count; i++) 
 { 
 encoder["L_PAYMENTREQUEST_0_NAME" + i] = 
myOrderList[i].Product.ProductName.ToString(); 
 encoder["L_PAYMENTREQUEST_0_AMT" + i] = 
myOrderList[i].Product.UnitPrice.ToString(); 
 encoder["L_PAYMENTREQUEST_0_QTY" + i] = 
myOrderList[i].Quantity.ToString(); 
 } 
 } 
string pStrrequestforNvp = encoder.Encode(); 
 string pStresponsenvp = HttpCall(pStrrequestforNvp); 
 
 NVPCodec decoder = new NVPCodec(); 
 decoder.Decode(pStresponsenvp); 
 
 string strAck = decoder["ACK"].ToLower(); 
 if (strAck != null && (strAck == "success" || strAck == 
"successwithwarning")) 
 { 
 token = decoder["TOKEN"];
     string ECURL = "https://" + host + "/cgi-bin/webscr?cmd=_express-checkout"+"&token="+ token;
     retMsg = ECURL; 
 return true; 
     } 
 else 
 { 
 retMsg = "ErrorCode=" + decoder["L_ERRORCODE0"] + "&" + 
 "Desc=" + decoder["L_SHORTMESSAGE0"] + "&" + 
 "Desc2=" + decoder["L_LONGMESSAGE0"]; 
 return false; 
 } 

        public NVPCodec ECSetExpressCheckoutCode(string returnURL, string appName,string appCode, string cancelURL, string appAMT, string paymentType, string currencyCode)
        {
            NVPCallerServices caller = new NVPCallerServices();
            IAPIProfile profile = ProfileFactory.createSignatureAPIProfile();
            /*
             WARNING: Do not embed plaintext credentials in your application code.
             Doing so is insecure and against best practices.
             Your API credentials must be handled securely. Please consider
             encrypting them for use in any production environment, and ensure
             that only authorized individuals may view or modify them.
             */

            // Set up your API credentials, PayPal end point, API operation and version.
            if (System.Configuration.ConfigurationManager.AppSettings["ENVIRONMENT"].ToString() == "T")
            {
                profile.APIUsername = "sdk-three_api1.sdk.com";
                profile.APIPassword = "QFZCWN5HZM8VBG7Q";
                profile.APISignature = "AVGidzoSQiGWu.lGj3z15HLczXaaAcK6imHawrjefqgclVwBe8imgCHZ";
                profile.Environment = "sandbox";
            }
            else if (System.Configuration.ConfigurationManager.AppSettings["ENVIRONMENT"].ToString() == "L")
            {

                profile.APIUsername = "murty.korada_api1.cybertech.com";
                profile.APIPassword = "KKKC8PY8E4R9LN48";
                profile.APISignature = "AFcWxV21C7fd0v3bYYYRCpSSRl31Ab5GxWPc-1XSb8rJctwNCFHIYb84";
                profile.Environment = "live";
            }
            else
            {
                profile.APIUsername = "sdk-three_api1.sdk.com";
                profile.APIPassword = "QFZCWN5HZM8VBG7Q";
                profile.APISignature = "AVGidzoSQiGWu.lGj3z15HLczXaaAcK6imHawrjefqgclVwBe8imgCHZ";
                profile.Environment = "sandbox";
            }
            caller.APIProfile = profile;
            NVPCodec encoder = new NVPCodec();
            encoder["VERSION"] =  "65.1";
            encoder["METHOD"] =  "SetExpressCheckout";
            // Add request-specific fields to the request.
            encoder["RETURNURL"] =  returnURL;
            encoder["CANCELURL"] =  cancelURL;
            encoder["AMT"] = appAMT;
            encoder["ITEMCATEGORY"] = "Digital";
            encoder["L_NAME0"] = appName;
            encoder["L_NUMBER0"] = appCode;
            encoder["L_AMT0"] = appAMT;
            encoder["L_QTY0"] ="1";
            encoder["PAYMENTACTION"] =  paymentType;
            encoder["CURRENCYCODE"] =  currencyCode;
            encoder["SOLUTIONTYPE"] = "Sole";
            // Execute the API operation and obtain the response.
            string pStrrequestforNvp= encoder.Encode();
            string pStresponsenvp=caller.Call(pStrrequestforNvp);

            NVPCodec decoder = new NVPCodec();
            decoder.Decode(pStresponsenvp);
            return decoder;
        }

    /// <summary>
    /// ConfirmPayment: The method that calls DoExpressCheckoutPayment, invoked from the 
    /// Billing Page EC placement
    /// </summary>
    /// <param name="token"></param>
    /// <param ref name="retMsg"></param>
    /// <returns></returns>
    public bool ConfirmPayment(string finalPaymentAmount, string token, string PayerId, ref NVPCodec decoder, ref string retMsg )
    {
        if (Env == "pilot")
        {
            pendpointurl = "https://pilot-payflowpro.paypal.com";
        }

        NVPCodec encoder = new NVPCodec();

        encoder["TOKEN"] = token;
        encoder["TENDER"] = "P";
        encoder["ACTION"] = "D";
        if ("Authorization" == "Sale")
        {
            encoder["TRXTYPE"] = "A";
        }
        else /* sale */
        {
            encoder["TRXTYPE"] = "S";
        }
        encoder["PAYERID"] = PayerId;
        encoder["AMT"] = finalPaymentAmount;

        // unique request ID
        string unique_id;

        if (HttpContext.Current.Session["unique_id"] == null)
        {
            System.Guid uid = System.Guid.NewGuid();
            unique_id = uid.ToString();
            HttpContext.Current.Session["unique_id"] = unique_id;
        }
        else
        {
            unique_id = (string)HttpContext.Current.Session["unique_id"];
        }

        string pStrrequestforNvp = encoder.Encode();
        string pStresponsenvp = HttpCall(pStrrequestforNvp,unique_id);

        decoder = new NVPCodec();
        decoder.Decode(pStresponsenvp);

        string strAck = decoder["RESULT"].ToLower();
        if (strAck != null && strAck == "0")
        {
            return true;
        }
        else
        {
            retMsg = "ErrorCode=" + strAck + "&" +
                "Desc=" + decoder["RESPMSG"];

            return false;
        }
    }

        public string MassPayCode(string emailSubject,string receiverType,string currencyCode,string ReceiverEmail0,string amount0,string UniqueID0,string Note0,string ReceiverEmail1,string amount1,string UniqueID1,string Note1)
        {
            NVPCallerServices caller = new NVPCallerServices();
            IAPIProfile profile = ProfileFactory.createSignatureAPIProfile();
            /*
             WARNING: Do not embed plaintext credentials in your application code.
             Doing so is insecure and against best practices.
             Your API credentials must be handled securely. Please consider
             encrypting them for use in any production environment, and ensure
             that only authorized individuals may view or modify them.
             */

            // Set up your API credentials, PayPal end point, API operation and version.
            profile.APIUsername = "sdk-three_api1.sdk.com";
            profile.APIPassword = "QFZCWN5HZM8VBG7Q";
            profile.APISignature = "AVGidzoSQiGWu.lGj3z15HLczXaaAcK6imHawrjefqgclVwBe8imgCHZ";
            profile.Environment="sandbox";
            caller.APIProfile = profile;

            NVPCodec encoder = new NVPCodec();
            encoder["VERSION"] =  "51.0";
            encoder["METHOD"] =  "MassPay";

            // Add request-specific fields to the request.
            encoder["EMAILSUBJECT"] =  emailSubject;
            encoder["RECEIVERTYPE"] =  receiverType;
            encoder["CURRENCYCODE"]=currencyCode;

            if(ReceiverEmail0.Length>0)
            {
                encoder["L_EMAIL0"] =  ReceiverEmail0;
                encoder["L_Amt0"] =  amount0;
                encoder["L_UNIQUEID0"] =  UniqueID0;
                encoder["L_NOTE0"] =  Note0;
            }

            if(ReceiverEmail1.Length>0)
            {
                encoder["L_EMAIL1"] =  ReceiverEmail1;
                encoder["L_Amt1"] =  amount1;
                encoder["L_UNIQUEID1"] =  UniqueID1;
                encoder["L_NOTE1"] =  Note1;
            }

            // Execute the API operation and obtain the response.
            string pStrrequestforNvp= encoder.Encode();
            string pStresponsenvp=caller.Call(pStrrequestforNvp);

            NVPCodec decoder = new NVPCodec();
            decoder.Decode(pStresponsenvp);
            return decoder["ACK"];
        }

    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            // Verify user has completed the checkout process.
            if (Session["userCheckoutCompleted"] != "true")
            {
                Session["userCheckoutCompleted"] = "";
                Response.Redirect("CheckoutError.aspx?" + "Desc=Unvalidated%20Checkout.");
            }

            NVPAPICaller payPalCaller = new NVPAPICaller();

            string retMsg = "";
            string token = "";
            string finalPaymentAmount = "";
            string PayerID = "";
            NVPCodec decoder = new NVPCodec();

            token = Session["token"].ToString();
            PayerID = Session["payerId"].ToString();
            finalPaymentAmount = Session["payment_amt"].ToString();

            bool ret = payPalCaller.DoCheckoutPayment(finalPaymentAmount, token, PayerID, ref decoder, ref retMsg);
            if (ret)
            {
                // Retrieve PayPal confirmation value.
                string PaymentConfirmation = decoder["PAYMENTINFO_0_TRANSACTIONID"].ToString();
                TransactionId.Text = PaymentConfirmation;

                // Get dataaccess context.
                DataAccess da = new DataAccess();
                Customer aCustomer = (Customer)Session["Customer"];
                aCustomer.Orders[0].OrderID = PaymentConfirmation;
                aCustomer = CartFunctions.setOrderId(aCustomer, PaymentConfirmation);
                // Add order to DB.

                da.addCustomer(aCustomer);
                da.addOrder(aCustomer);
                da.addOrderline(aCustomer);

                // Clear Order

                aCustomer = CartFunctions.clearOrder(aCustomer);

            }
            else
            {
                Response.Redirect("CheckoutError.aspx?" + retMsg);
            }
        }
    }

        public NVPCodec ECGetExpressCheckoutCode(string token)
        {
            NVPCallerServices caller = new NVPCallerServices();
            IAPIProfile profile = ProfileFactory.createSignatureAPIProfile();
            /*
             WARNING: Do not embed plaintext credentials in your application code.
             Doing so is insecure and against best practices.
             Your API credentials must be handled securely. Please consider
             encrypting them for use in any production environment, and ensure
             that only authorized individuals may view or modify them.
             */

            // Set up your API credentials, PayPal end point, API operation and version.
            if (System.Configuration.ConfigurationManager.AppSettings["ENVIRONMENT"].ToString() == "T")
            {
                profile.APIUsername = "sdk-three_api1.sdk.com";
                profile.APIPassword = "QFZCWN5HZM8VBG7Q";
                profile.APISignature = "AVGidzoSQiGWu.lGj3z15HLczXaaAcK6imHawrjefqgclVwBe8imgCHZ";
                profile.Environment = "sandbox";
            }
            else if (System.Configuration.ConfigurationManager.AppSettings["ENVIRONMENT"].ToString() == "L")
            {
                profile.APIUsername = "murty.korada_api1.cybertech.com";
                profile.APIPassword = "KKKC8PY8E4R9LN48";
                profile.APISignature = "AFcWxV21C7fd0v3bYYYRCpSSRl31Ab5GxWPc-1XSb8rJctwNCFHIYb84";
                profile.Environment = "live";
            }
            else
            {
                profile.APIUsername = "sdk-three_api1.sdk.com";
                profile.APIPassword = "QFZCWN5HZM8VBG7Q";
                profile.APISignature = "AVGidzoSQiGWu.lGj3z15HLczXaaAcK6imHawrjefqgclVwBe8imgCHZ";
                profile.Environment = "sandbox";
            }
            caller.APIProfile = profile;

            NVPCodec encoder = new NVPCodec();
            encoder["VERSION"] =  "65.1";
            encoder["METHOD"] =  "GetExpressCheckoutDetails";

            // Add request-specific fields to the request.
            encoder["TOKEN"] =  token; // Pass the token returned in SetExpressCheckout.

            // Execute the API operation and obtain the response.
            string pStrrequestforNvp= encoder.Encode();
            string pStresponsenvp=caller.Call(pStrrequestforNvp);

            NVPCodec decoder = new NVPCodec();
            decoder.Decode(pStresponsenvp);
            return decoder;
        }

        public string ECDoExpressCheckout(string token, string payerID, string amount, Cart cart)
        {
            Settings settings = new Settings();
            NVPCallerServices caller = new NVPCallerServices();
            IAPIProfile profile = getProfile();
            caller.APIProfile = profile;

            NVPCodec encoder = new NVPCodec();
            encoder.Add("VERSION","84.0");
            encoder.Add("METHOD","DoExpressCheckoutPayment");

            // Add request-specific fields to the request.
            encoder.Add("TOKEN",token);
            encoder.Add("PAYERID",payerID);
            encoder.Add("RETURNURL",getSiteURL() + "Payment/PayPalCheckout");
            encoder.Add("CANCELURL",getSiteURL() + "Payment");
            encoder.Add("PAYMENTREQUEST_0_AMT",amount);
            encoder.Add("PAYMENTREQUEST_0_PAYMENTACTION","Sale");
            encoder.Add("PAYMENTREQUEST_0_CURRENCYCODE","USD");
            encoder.Add("BRANDNAME",settings.Get("SiteName"));
            encoder.Add("LOGIN","Login");
            encoder.Add("HDRIMG",settings.Get("EmailLogo"));
            encoder.Add("CUSTOMERSERVICENUMBER",settings.Get("PhoneNumber"));
            encoder.Add("PAYMENTREQUEST_0_SHIPPINGAMT",cart.shipping_price.ToString());
            encoder.Add("PAYMENTREQUEST_0_DESC","Your " + settings.Get("SiteName") + " Order");
            encoder.Add("ALLOWNOTE","0");
            encoder.Add("NOSHIPPING","1");
            int count = 0;
            decimal total = 0;
            foreach (CartItem item in cart.CartItems) {
                encoder.Add("L_PAYMENTREQUEST_0_NUMBER" + count, item.partID.ToString());
                encoder.Add("L_PAYMENTREQUEST_0_NAME" + count, item.shortDesc);
                encoder.Add("L_PAYMENTREQUEST_0_AMT" + count, String.Format("{0:N2}", item.price));
                encoder.Add("L_PAYMENTREQUEST_0_QTY" + count, item.quantity.ToString());
                encoder.Add("L_PAYMENTREQUEST_0_ITEMCATEGORY" + count, "Physical");
                encoder.Add("L_PAYMENTREQUEST_0_ITEMURL" + count, settings.Get("SiteURL") + "part/" + item.partID);
                total += item.price * item.quantity;
                count++;
            }
            encoder.Add("PAYMENTREQUEST_0_TAXAMT", String.Format("{0:N2}", cart.tax));
            encoder.Add("PAYMENTREQUEST_0_ITEMAMT", String.Format("{0:N2}", total));
            // Execute the API operation and obtain the response.
            string pStrrequestforNvp = encoder.Encode();
            string pStresponsenvp = caller.Call(pStrrequestforNvp);

            NVPCodec decoder = new NVPCodec();
            decoder.Decode(pStresponsenvp);
            return decoder["ACK"];
        }

        public string DoDirectPaymentCode(string paymentAction,string amount,string creditCardType,string creditCardNumber,string expdate_month,string cvv2Number,string firstName,string lastName,string address1,string city,string state,string zip,string countryCode,string currencyCode)
        {
            NVPCallerServices caller = new NVPCallerServices();
            IAPIProfile profile = ProfileFactory.createSignatureAPIProfile();
            /*
             WARNING: Do not embed plaintext credentials in your application code.
             Doing so is insecure and against best practices.
             Your API credentials must be handled securely. Please consider
             encrypting them for use in any production environment, and ensure
             that only authorized individuals may view or modify them.
             */

            // Set up your API credentials, PayPal end point, API operation and version.
            profile.APIUsername = "sdk-three_api1.sdk.com";
            profile.APIPassword = "QFZCWN5HZM8VBG7Q";
            profile.APISignature = "AVGidzoSQiGWu.lGj3z15HLczXaaAcK6imHawrjefqgclVwBe8imgCHZ";
            profile.Environment="sandbox";
            caller.APIProfile = profile;

            NVPCodec encoder = new NVPCodec();
            encoder["VERSION"] =  "51.0";
            encoder["METHOD"] =  "DoDirectPayment";

            // Add request-specific fields to the request.
            encoder["PAYMENTACTION"] =  paymentAction;
            encoder["AMT"] =  amount;
            encoder["CREDITCARDTYPE"] =  creditCardType;
            encoder["ACCT"] =  creditCardNumber;
            encoder["EXPDATE"] =  expdate_month;
            encoder["CVV2"] =  cvv2Number;
            encoder["FIRSTNAME"] =  firstName;
            encoder["LASTNAME"] =  lastName;
            encoder["STREET"] =  address1;
            encoder["CITY"] =  city;
            encoder["STATE"] =  state;
            encoder["ZIP"] =  zip;
            encoder["COUNTRYCODE"] = countryCode;
            encoder["CURRENCYCODE"] =  currencyCode;

            // Execute the API operation and obtain the response.
            string pStrrequestforNvp= encoder.Encode();
            string pStresponsenvp=caller.Call(pStrrequestforNvp);

            NVPCodec decoder = new NVPCodec();
            decoder.Decode(pStresponsenvp);
            return decoder["ACK"];
        }