DirectPayment method Paypal problem

I am trying to implement Direct payment method as I have user's credit card information etc in my database. This is the sample that I am referring:

using System;
using System.Collections.Generic;
using System.Text;
using com.paypal.sdk.services;
using com.paypal.sdk.profiles;
using com.paypal.sdk.util;
using com.paypal.soap.api;

namespace ASPDotNetSamples
{
    public class DoDirectPayment
    {
        public DoDirectPayment()
        {
        }
        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)
        {

            com.paypal.soap.api.DoDirectPaymentReq req = new com.paypal.soap.api.DoDirectPaymentReq();


            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";
        开发者_开发百科    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"];

        }
    }
}

This is the link:

https://cms.paypal.com/cms_content/US/en_US/files/developer/nvp_DoDirectPayment_cs.txt

However, I am getting error 'NVPCallerServices' cannot be found. I already have reference to paypal_base. Can anybody tell me what is the issue?

Yeah, thats the Pay Pal API :)

The sample is likely a bit outdated. The NVPCallerServices class seems to be named CallerServices now.

So try to replace the line

NVPCallerServices caller = new NVPCallerServices();

with

CallerServices caller = new CallerServices();