c# - Print raw data to a thermal-printer using .NET

Question

I'm trying to print out raw ascii data to a thermal printer. I do this by using this code example: http://support.microsoft.com/kb/322091 but my printer prints always only one character and this not until I press the form feed button. If I print something with notepad the printer will do a form feed automatically but without printing any text.

The printer is connected via usb over a lpt2usb adapter and Windows 7 uses the "Generic -> Generic / Text Only" driver.

Anyone knows what is going wrong? How is it possible to print some words and do some form feeds? Are there some control characters I have to send? And if yes: How do I send them?

Edit 14.04.2010 21:51

My code (C#) looks like this:

PrinterSettings s =  new PrinterSettings();
s.PrinterName = "Generic / Text Only";

RawPrinterHelper.SendStringToPrinter(s.PrinterName, "Test");

This code will return a "T" after I pressed the form feed button (This litte black button here: swissmania.ch/images/935-151.jpg - sorry, not enough reputation for two hyperlinks)

Edit 15.04.2010 16:56

I'm using now the code form here: c-sharpcorner.com/UploadFile/johnodonell/PrintingDirectlytothePrinter11222005001207AM/PrintingDirectlytothePrinter.aspx

I modified it a bit that I can use the following code:

byte[] toSend;
// 10 = line feed
// 13 carriage return/form feed
toSend = new byte[1] { 13 };
PrintDirect.WritePrinter(lhPrinter, toSend, toSend.Length, ref pcWritten);

Running this code has the same effekt like pressing the form feed button, it works fine!

But code like this still does not work:

byte[] toSend;
// 10 = line feed
// 13 carriage return/form feed
toSend = new byte[2] { 66, 67 };
PrintDirect.WritePrinter(lhPrinter, toSend, toSend.Length, ref pcWritten);

This will print out just a "B" but I expect "BC" and after running any code I have to reconnect the USB cable to make it work agian. Any ideas?

Answer 1

Quick step by step solution

Because code was not provided, I make it work with help of provided links, and here is the code:

Code

using System;
using System.Runtime.InteropServices;
using System.Windows;

[StructLayout(LayoutKind.Sequential)]
public struct DOCINFO {
    [MarshalAs(UnmanagedType.LPWStr)]
    public string pDocName;
    [MarshalAs(UnmanagedType.LPWStr)] 
    public string pOutputFile;
    [MarshalAs(UnmanagedType.LPWStr)] 
    public string pDataType;
}

public class PrintDirect {
    [DllImport("winspool.drv", CharSet = CharSet.Unicode, ExactSpelling = false, CallingConvention = CallingConvention.StdCall)]
    public static extern long OpenPrinter(string pPrinterName, ref IntPtr phPrinter, int pDefault);

    [DllImport("winspool.drv", CharSet = CharSet.Unicode, ExactSpelling = false, CallingConvention = CallingConvention.StdCall)]
    public static extern long StartDocPrinter(IntPtr hPrinter, int Level, ref DOCINFO pDocInfo);

    [DllImport("winspool.drv", CharSet = CharSet.Unicode, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
    public static extern long StartPagePrinter(IntPtr hPrinter);

    [DllImport("winspool.drv", CharSet = CharSet.Ansi, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
    public static extern long WritePrinter(IntPtr hPrinter, string data, int buf, ref int pcWritten);

    [DllImport("winspool.drv", CharSet = CharSet.Unicode, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
    public static extern long EndPagePrinter(IntPtr hPrinter);

    [DllImport("winspool.drv", CharSet = CharSet.Unicode, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
    public static extern long EndDocPrinter(IntPtr hPrinter);

    [DllImport("winspool.drv", CharSet = CharSet.Unicode, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
    public static extern long ClosePrinter(IntPtr hPrinter);
}

private void Print(String printerAddress, String text, String documentName) {
    IntPtr printer = new IntPtr();

    // A pointer to a value that receives the number of bytes of data that were written to the printer.
    int pcWritten = 0;

    DOCINFO docInfo = new DOCINFO();
    docInfo.pDocName = documentName;
    docInfo.pDataType = "RAW";

    PrintDirect.OpenPrinter(printerAddress, ref printer, 0);
    PrintDirect.StartDocPrinter(printer, 1, ref docInfo);
    PrintDirect.StartPagePrinter(printer);

    try {
    PrintDirect.WritePrinter(printer, text, text.Length, ref pcWritten);
    } catch (Exception e) {
        Console.WriteLine(e.Message);
    }

    PrintDirect.EndPagePrinter(printer);
    PrintDirect.EndDocPrinter(printer);
    PrintDirect.ClosePrinter(printer);
}

Usage

String printerAddress = "\\ComputerName\PrinterName";
String documentName = "My document";
String documentText = "This is an example of printing directly to a printer.";

this.Print(printerAddress, documentText, documentName);

Sources:

• How to send raw data to a printer by using Visual C# .NET (link is no longer active)
• HOWTO: Send Raw Data to a Printer by Using the Win32 API