Writing nice receipt in C# WPF for printing on thermal printer POS

In the past when doing this I split up the receipt into separate parts that used different fonts or alignments such as Header, Body, Footer.

I used the following class layout to encapsulate my printed text definition. (where you get the Font from and how you manage its lifetime is up to you)

public class PrintText
{
    public PrintText(string text, Font font) : this(text, font, new StringFormat()) {}

    public PrintText(string text, Font font, StringFormat stringFormat)
    {
        Text = text;
        Font = font;
        StringFormat = stringFormat;
    }

    public string Text { get; set; }

    public Font Font { get; set; }

    /// <summary> Default is horizontal string formatting </summary>
    public StringFormat StringFormat { get; set; }
}

When there are longer lists of texts using the same font & padding then using a stringbuilder to build up your text makes life easy so you get a visual of how it will look just from inspecting your code.

If you had static text you can fit it all together as so:

var sb = new StringBuilder();
sb.AppendLine("Start of receipt");
sb.AppendLine("================");
sb.AppendLine("Item 1");
sb.AppendLine("Item 2");
sb.AppendLine("================");

Or if the data is a bit dynamic pass in some object you can iterate over and append your formatted text:

private class ReceiptItem
{
    public string Name { get; set; }

    public decimal Cost { get; set; }

    public int Amount { get; set; }

    public int Discount { get; set; }

    public decimal Total { get { return Cost * Amount; } }
}

const int FIRST_COL_PAD = 20;
const int SECOND_COL_PAD = 7;
const int THIRD_COL_PAD = 20;

var sb = new StringBuilder();
sb.AppendLine("Start of receipt");
sb.AppendLine("================");

foreach (var item in receiptItems)
{
    sb.Append(item.Name.PadRight(FIRST_COL_PAD));

    var breakDown = item.Amount > 0 ? item.Amount + "x" + item.Cost : string.Empty;
    sb.Append(breakDown.PadRight(SECOND_COL_PAD));

    sb.AppendLine(string.Format("{0:0.00} A", item.Total).PadLeft(THIRD_COL_PAD));

    if (item.Discount > 0)
    {
        sb.Append(string.Format("DISCOUNT {0:D2}%", item.Discount).PadRight(FIRST_COL_PAD + SECOND_COL_PAD));
        sb.Append(string.Format("{0:0.00} A", -(item.Total / 100 * item.Discount)).PadLeft(THIRD_COL_PAD));
        sb.AppendLine();
    }
}

sb.AppendLine("================");

The output will look like:

Start of receipt
================
Joes Food           1x10      10.00 A
DISCOUNT 10%                  -1.00 A
Fun Facts           1x20      20.00 A
DISCOUNT 15%                  -3.00 A
Bag of Sand         7x40     280.00 A
================

Using the PrintText class earlier we can store our nicely formatted string builder output

var printText = new PrintText(sb.ToString(), new Font("Monospace Please...", 8));

Then finally use that when attempting to draw the string

var layoutArea = new SizeF(AvailableWidth, 0);
SizeF stringSize = g.MeasureString(printText.Text, printText.Font, layoutArea, printText.StringFormat);

RectangleF rectf = new RectangleF(new PointF(), new SizeF(AvailableWidth, stringSize.Height));

g.DrawString(printText.Text, printText.Font, Brushes.Black, rectf, printText.StringFormat);

You can also play around with a few different graphical tweaks if the text doesn't print quite right such as:

g.SmoothingMode = SmoothingMode.AntiAlias;
g.InterpolationMode = InterpolationMode.HighQualityBicubic;
g.PixelOffsetMode = PixelOffsetMode.HighQuality;

I have designed a simple and smooth receipt design, i hope it will help you.

public class PrintJob
{
    private PrintDocument PrintDocument;
    private Graphics graphics;
    private Order order { set; get; }
    private Shop shop { set; get; }
    private int InitialHeight = 360;
    public PrintJob(Order order, Shop shop)
    {
        this.order = order;
        this.shop = shop;
        AdjustHeight();
    }
    private void AdjustHeight()
    {
        var capacity = 5 * order.ItemTransactions.Capacity;
        InitialHeight += capacity;

        capacity = 5 * order.DealTransactions.Capacity;
        InitialHeight += capacity;
    }
    public void Print(string printername)
    {
        PrintDocument = new PrintDocument();
        PrintDocument.PrinterSettings.PrinterName = printername;

        PrintDocument.PrintPage += new PrintPageEventHandler(FormatPage);
        PrintDocument.Print();
    }
    void DrawAtStart(string text, int Offset)
    {
        int startX = 10;
        int startY = 5;
        Font minifont = new Font("Arial", 5);

        graphics.DrawString(text, minifont,
                 new SolidBrush(Color.Black), startX + 5, startY + Offset);
    }
    void InsertItem(string key, string value, int Offset)
    {
        Font minifont = new Font("Arial", 5);
        int startX = 10;
        int startY = 5;

        graphics.DrawString(key, minifont,
                     new SolidBrush(Color.Black), startX + 5, startY + Offset);

        graphics.DrawString(value, minifont,
                 new SolidBrush(Color.Black), startX + 130, startY + Offset);
    }
    void InsertHeaderStyleItem(string key, string value, int Offset)
    {
        int startX = 10;
        int startY = 5;
        Font itemfont = new Font("Arial", 6, FontStyle.Bold);

        graphics.DrawString(key, itemfont,
                     new SolidBrush(Color.Black), startX + 5, startY + Offset);

        graphics.DrawString(value, itemfont,
                 new SolidBrush(Color.Black), startX + 130, startY + Offset);
    }
    void DrawLine(string text, Font font, int Offset, int xOffset)
    {
        int startX = 10;
        int startY = 5;
        graphics.DrawString(text, font,
                 new SolidBrush(Color.Black), startX + xOffset, startY + Offset);
    }
    void DrawSimpleString(string text, Font font, int Offset, int xOffset)
    {
        int startX = 10;
        int startY = 5;
        graphics.DrawString(text, font,
                 new SolidBrush(Color.Black), startX + xOffset, startY + Offset);
    }
    private void FormatPage(object sender, PrintPageEventArgs e)
    {
        graphics = e.Graphics;
        Font minifont = new Font("Arial", 5);
        Font itemfont = new Font("Arial", 6);
        Font smallfont = new Font("Arial", 8);
        Font mediumfont = new Font("Arial", 10);
        Font largefont = new Font("Arial", 12);
        int Offset = 10;
        int smallinc = 10, mediuminc = 12, largeinc = 15;

        //Image image = Resources.logo;
        //e.Graphics.DrawImage(image, startX + 50, startY + Offset, 100, 30);

        //graphics.DrawString("Welcome to HOT AND CRISPY", smallfont,
        //      new SolidBrush(Color.Black), startX + 22, startY + Offset);

        Offset = Offset + largeinc + 10;

        String underLine = "-------------------------------------";
        DrawLine(underLine, largefont, Offset, 0);

        Offset = Offset + mediuminc;
        DrawAtStart("Invoice Number: " + order.Invoice, Offset);

        if (!String.Equals(order.Customer.Address, "N/A"))
        {
            Offset = Offset + mediuminc;
            DrawAtStart("Address: " + order.Customer.Address, Offset);
        }

        if (!String.Equals(order.Customer.Phone, "N/A"))
        {
            Offset = Offset + mediuminc;
            DrawAtStart("Phone # : " + order.Customer.Phone, Offset);
        }

        Offset = Offset + mediuminc;
        DrawAtStart("Date: " + order.Date, Offset);

        Offset = Offset + smallinc;
        underLine = "-------------------------";
        DrawLine(underLine, largefont, Offset, 30);

        Offset = Offset + largeinc;

        InsertHeaderStyleItem("Name. ", "Price. ", Offset);

        Offset = Offset + largeinc;
        foreach (var itran in order.ItemTransactions)
        {
            InsertItem(itran.Item.Name + " x " + itran.Quantity, itran.Total.CValue, Offset);
            Offset = Offset + smallinc;
        }
        foreach (var dtran in order.DealTransactions)
        {
            InsertItem(dtran.Deal.Name, dtran.Total.CValue, Offset);
            Offset = Offset + smallinc;

            foreach (var di in dtran.Deal.DealItems)
            {
                InsertItem(di.Item.Name + " x " + (dtran.Quantity * di.Quantity), "", Offset);
                Offset = Offset + smallinc;
            }
        }

        underLine = "-------------------------";
        DrawLine(underLine, largefont, Offset, 30);

        Offset = Offset + largeinc;
        InsertItem(" Net. Total: ", order.Total.CValue, Offset);

        if (!order.Cash.Discount.IsZero())
        {
            Offset = Offset + smallinc;
            InsertItem(" Discount: ", order.Cash.Discount.CValue, Offset);
        }

        Offset = Offset + smallinc;
        InsertHeaderStyleItem(" Amount Payable: ", order.GrossTotal.CValue, Offset);

        Offset = Offset + largeinc;
        String address = shop.Address;
        DrawSimpleString("Address: " + address, minifont, Offset, 15);

        Offset = Offset + smallinc;
        String number = "Tel: " + shop.Phone1 + " - OR - " + shop.Phone2;
        DrawSimpleString(number, minifont, Offset, 35);

        Offset = Offset + 7;
        underLine = "-------------------------------------";
        DrawLine(underLine, largefont, Offset, 0);

        Offset = Offset + mediuminc;
        String greetings = "Thanks for visiting us.";
        DrawSimpleString(greetings, mediumfont, Offset, 28);

        Offset = Offset + mediuminc;
        underLine = "-------------------------------------";
        DrawLine(underLine, largefont, Offset, 0);

        Offset += (2 * mediuminc);
        string tip = "TIP: -----------------------------";
        InsertItem(tip, "", Offset);

        Offset = Offset + largeinc;
        string DrawnBy = "Meganos Softwares: 0312-0459491 - OR - 0321-6228321";
        DrawSimpleString(DrawnBy, minifont, Offset, 15);
    }
}

Some code to add the image has been commented here due to our requirements you can add can add your logo at header, as you can see in second image.