Code Examples – C# Code Examples

As Client Only

The following is an example of the simplest form of making a program that actually makes a payment. It is a windows form with one button making a payment for 10 SEK and printing the receipt to a TextBox. The only methods used are Create, Start, OpenAsync and PaymentAsync.

Warning: The IP address to terminal needs to be changed

Heads up: The first attempt will fail, since OpenAsync is successful but the terminal starts communicating with its host. Click the button again to start the payment.

Simplest form of implementation - Happy Flow

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using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using SwpTrmLib;
using SwpTrmLib.NexoTypes;

namespace WindowsFormsApp1
{
    public partial class Form1 : Form, ISwpTrmCallbackInterface
    {
        ISwPTrmIf_1 PAX;

        public Form1()
        {
            InitializeComponent();

        }
        private async void button1_Click(object sender, EventArgs e)
        {
            if (PAX == null)
            {
                LoginToTerminal();
            }
            var result = await PAX.PaymentAsync(10);
            if (result.ResponseResult == NexoResponseResult.Success)
            {
                textBox1.AppendText("APPROVED TRANSACTION" + Environment.NewLine);
            }
            else
            {
                textBox1.AppendText("REJECTED TRANSACTION" + Environment.NewLine);
                textBox1.AppendText(result.ResponseText + Environment.NewLine);
            }
            // The result contains the receipt information
            textBox1.AppendText(result.ReceiptBlob + Environment.NewLine);
        }

        private void CreatePAXInstance()
        {
            PAX = PAXTrmImp_1.Create(new SwpIfConfig(), this);

            PAX.Start(new SaleApplInfo()
            {
                ApplicationName = "Quick Demo-Client Only",
                ProviderIdentification = "SwP",
                SoftwareVersion = "0.1",
                POIID = "A-TEST-POIID",
                SaleCapabilities = SaleCapabilitiesEnum.PrinterReceipt.ToString() // Client only mode!
            });
        }
        private async void LoginToTerminal()
        {
            if (PAX == null)
            {
                CreatePAXInstance();
            }

            PAX.TerminalAddress = "192.168.1.34:11000";

            var res = await PAX.OpenAsync();
            if (res.Result == ResponseResult.Success)
            {
                textBox1.AppendText("Terminal connected " + Environment.NewLine);
                textBox1.AppendText("Terminal: " + res.SerialNumber + Environment.NewLine);
                textBox1.AppendText("Terminal version: " + res.SoftwareVersion + Environment.NewLine);
            }
            else
            {
                textBox1.AppendText("Failed to connect terminal " + Environment.NewLine);
                textBox1.AppendText(res.Text + Environment.NewLine);
            }
        }
        public void ConfirmationHandler(string text, IConfirmationResult callback)
        {
            throw new NotImplementedException();
        }

        public void EventNotificationHandler(EventToNotifyEnumeration type, string text)
        {
            throw new NotImplementedException();
        }

        private async void Form1_FormClosing(object sender, FormClosingEventArgs e)
        {
            await PAX.CloseAsync();
            PAX.Stop();
        }
    }
}

As Client and Server

Based on Simplest Client only the following runs as a server too. The difference is:

Removed SalesCapabilites in call to Start
Subscribed to the OnTerminalDisplay event
Added code to the callback EventNotificationHandler

Heads up: When running as a server the program needs elevated privileges. It may be avoided by entering the following command as administrator:

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netsh http add urlacl url=http://*:11000/EPASSaleToPOI/3.1/ user=Everyone

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where :11000 is the default port. If listening to another port the command must be changed.

Simplest Client And Server form of implementation - Happy Flow

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using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using SwpTrmLib;
using SwpTrmLib.NexoTypes;

namespace WindowsFormsApp1
{
    public partial class Form1 : Form, ISwpTrmCallbackInterface
    {
        ISwPTrmIf_1 PAX;

        public Form1()
        {
            InitializeComponent();

        }
        private async void button1_Click(object sender, EventArgs e)
        {
            if (PAX == null)
            {
                LoginToTerminal();
            }
            var res = await PAX.PaymentAsync(10);
            if (res.ResponseResult == NexoResponseResult.Success)
            {
                textBox1.AppendText("APPROVED TRANSACTION" + Environment.NewLine);
            }
            else
            {
                textBox1.AppendText("REJECTED TRANSACTION" + Environment.NewLine);
                textBox1.AppendText(res.ResponseText + Environment.NewLine);
            }
            // The result contains the receipt information
            textBox1.AppendText(res.ReceiptBlob + Environment.NewLine);
        }

        private void CreatePAXInstance()
        {
            PAX = PAXTrmImp_1.Create(new SwpIfConfig(), this);

            PAX.Start(new SaleApplInfo()
            {
                ApplicationName = "Quick Demo",
                ProviderIdentification = "SwP",
                SoftwareVersion = "0.1",
                POIID = "A-TEST-POIID",
                //SaleCapabilities = SaleCapabilitiesEnum.PrinterReceipt.ToString()
            });

            PAX.OnTerminalDisplay += PAX_OnTerminalDisplay;
        }
        // A DisplayRequest from the terminal
        private void PAX_OnTerminalDisplay(string message)
        {
            textBox1.AppendText(message + Environment.NewLine);
        }

        private async void LoginToTerminal()
        {
            if (PAX == null)
            {
                CreatePAXInstance();
            }

            PAX.TerminalAddress = "192.168.1.34:11000";

            var res = await PAX.OpenAsync();
            if (res.Result == ResponseResult.Success)
            {
                textBox1.AppendText("Terminal connected " + Environment.NewLine);
                textBox1.AppendText("Terminal: " + res.SerialNumber + Environment.NewLine);
                textBox1.AppendText("Terminal version: " + res.SoftwareVersion + Environment.NewLine);
            }
            else
            {
                textBox1.AppendText("Failed to connect terminal " + Environment.NewLine);
                textBox1.AppendText(res.Text + Environment.NewLine);
            }
        }
        public void ConfirmationHandler(string text, IConfirmationResult callback)
        {
            throw new NotImplementedException();
        }

        public void EventNotificationHandler(EventToNotifyEnumeration type, string text)
        {
            textBox1.AppendText($"Event: {type} - {text}" + Environment.NewLine);
        }

        private async void Form1_FormClosing(object sender, FormClosingEventArgs e)
        {
            if (PAX != null)
            {
                await PAX.CloseAsync();
                PAX.Stop();
            }
        }
    }
}

Changes From Client Only

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    PAX.Start(new SaleApplInfo()
    {
        ApplicationName = "Quick Demo",
        ProviderIdentification = "SwP",
        SoftwareVersion = "0.1",
        POIID = "A-POIID",
        //SaleCapabilities = SaleCapabilitiesEnum.PrinterReceipt.ToString()
    });

    PAX.OnTerminalDisplay += PAX_OnTerminalDisplay;

and

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public void EventNotificationHandler(EventToNotifyEnumeration type, string text)
{
    textBox1.AppendText($"Event: {type} - {text}" + Environment.NewLine);
}

Get CNA For Customer

Based on either Simplest Client or Client And Server, let’s take it a bit further and find out who the customer is before starting the actual purchase transaction. The only change is in the button1_click where GetPaymentInstrumentAsync is called. The result contains among others masked PAN and CNA - CardNumberAlias.

This is a very simple way to handle members. The CNA will be the same in all our PAX terminals.

Get to know the customer before deciding amount - Happy Flow

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    private async void button1_Click(object sender, EventArgs e)
    {
        if (PAX == null)
        {
            LoginToTerminal();
        }
        var cardres = await PAX.GetPaymentInstrumentAsync();
        if (cardres.Result == NexoResponseResult.Success)
        {
            textBox1.AppendText($"CNA: {cardres.CNA}" + Environment.NewLine);
            textBox1.AppendText($"for card: {cardres.PAN}" + Environment.NewLine);

            var res = await PAX.PaymentAsync(10);
            if (res.ResponseResult == NexoResponseResult.Success)
            {
                textBox1.AppendText("APPROVED TRANSACTION" + Environment.NewLine);
            }
            else
            {
                textBox1.AppendText("REJECTED TRANSACTION" + Environment.NewLine);
                textBox1.AppendText(res.ResponseText + Environment.NewLine);
            }
            // The result contains the receipt information
            textBox1.AppendText(res.ReceiptBlob + Environment.NewLine);
        }
    }

Handle Loyalty - Ask For Membership

Based on the version Get CNA For Customer, let’s see if CNA exists in the database and if so, give the customer a better price. If the costumer is not a member, ask them to join so they can get a better price next time.

The only change is to create a list of members and add CNA to that list if the customer wants to join. Other that creating the Members which is a list of strings, there are only changes in the button1_click. The important addition is the call to RequestCustomerConfirmationAsync. It requests the terminal to show a message and asks for a yes/no response. The member CustomerConfirmation of the result is true or false.

Note!: The delay before a new request after a finished transaction is needed. If the delay is not added, the request will get a failure due to terminal being busy

Remember: to add List<string> Member;

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private async void button1_Click(object sender, EventArgs e)
{
    decimal priceofproduct = 10;
    bool asktojoin = false;

    if (PAX == null)
    {
        LoginToTerminal();
        if (Members == null) {
            Members = new List<string>();
        }
    }
    var cardres = await PAX.GetPaymentInstrumentAsync();
    if (cardres.Result == NexoResponseResult.Success)
    {
        textBox1.AppendText($"CNA: {cardres.CNA}" + Environment.NewLine);
        textBox1.AppendText($"for card: {cardres.PAN}" + Environment.NewLine);

        if (Members.Contains(cardres.CNA))
        {
            priceofproduct = 8;
        }
        else
        {
            asktojoin = true;
        }

        var res = await PAX.PaymentAsync(priceofproduct);
        if (res.ResponseResult == NexoResponseResult.Success)
        {
            textBox1.AppendText("APPROVED TRANSACTION" + Environment.NewLine);
        }
        else
        {
            textBox1.AppendText("REJECTED TRANSACTION" + Environment.NewLine);
            textBox1.AppendText(res.ResponseText + Environment.NewLine);
        }
        // The result contains the receipt information
        textBox1.AppendText(res.ReceiptBlob + Environment.NewLine);

        if (asktojoin)
        {
            await Task.Delay(3000);
            var confirmres = await PAX.RequestCustomerConfirmationAsync("Would you like to join?");
            if (confirmres.ResponseResult == NexoResponseResult.Success && confirmres.Confirmation == true)
            {
                Members.Add(cardres.CNA);
            }
        }
    }
}