How to send raw data to a printer by using Visual C# .NET

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Article ID: 322091 - View products that this article applies to.
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SUMMARY

This step-by-step article shows how to use Win32 spooler functions from a program that you create by using Visual C# .NET.

More Information

To send raw data to a printer from the Microsoft .NET Framework, your program must work with Win32 spooler functions. Through the .NET Framework, you can print by using PrintDocument, PrintController, and associated classes. However, with the .NET Framework, you cannot send preformatted printer-ready data to a printer.

You may have to send raw data to a printer to do the following:
  • Send escape sequences.
  • Download, and then use soft fonts.
  • Spool preprinted files.
To send these types and other types of raw data to a printer, your code must work with Win32 Spooler Application Programmer Interfaces (APIs). The following code shows how to read the contents of a preformatted file into memory, and then send those bytes to the printer by using WritePrinter.

NOTE: You cannot use this approach in the same print job as a native PrintDocument print job. You must either use the .NET Framework to print or send your own print job bytes.

Create a Project That Prints Preformatted Data

  1. Start Visual Studio .NET. On the File menu, click New, and then click Project. Under Project Types, click the Visual C# Projects folder. On the Templates list, click Windows Application, and then click OK. By default, Form1 is created.
  2. On the View menu, click Toolbox to display the Toolbox, and then add a button to Form1. This button is named Button1.
  3. Add another button to Form1. This button is named Button2.
  4. Double-click Button1. The code window for the form appears.
  5. Replace the Button1_Click subroutine with the following code:
    private void button1_Click(object sender, System.EventArgs e)
    {
        // Allow the user to select a file.
        OpenFileDialog ofd = new OpenFileDialog();
        if( DialogResult.OK == ofd.ShowDialog(this) )
        {
            // Allow the user to select a printer.
            PrintDialog pd  = new PrintDialog();
            pd.PrinterSettings = new PrinterSettings();
            if( DialogResult.OK == pd.ShowDialog(this) )
            {
                // Print the file to the printer.
                RawPrinterHelper.SendFileToPrinter(pd.PrinterSettings.PrinterName, ofd.FileName);
            }
        }
    }
    					
  6. Replace the Button2_Click subroutine with the following code:
    private void button2_Click(object sender, System.EventArgs e)
    {
        string s = "Hello"; // device-dependent string, need a FormFeed?
        
        // Allow the user to select a printer.
        PrintDialog pd  = new PrintDialog();
        pd.PrinterSettings = new PrinterSettings();
        if( DialogResult.OK == pd.ShowDialog(this) )
        {
            // Send a printer-specific to the printer.
            RawPrinterHelper.SendStringToPrinter(pd.PrinterSettings.PrinterName, s);
        }
    }
    					
  7. Insert the following code at the top of the file:
    using System;
    using System.Drawing;
    using System.Drawing.Printing;
    using System.Windows.Forms;
    using System.Runtime.InteropServices;
    					
  8. Add the following code inside the main application namespace but outside any class definitions:
    public class RawPrinterHelper
    {
        // Structure and API declarions:
        [StructLayout(LayoutKind.Sequential, CharSet=CharSet.Ansi)]
        public class DOCINFOA
        {
            [MarshalAs(UnmanagedType.LPStr)] public string pDocName;
            [MarshalAs(UnmanagedType.LPStr)] public string pOutputFile;
            [MarshalAs(UnmanagedType.LPStr)] public string pDataType;
        }
        [DllImport("winspool.Drv", EntryPoint="OpenPrinterA", SetLastError=true, CharSet=CharSet.Ansi, ExactSpelling=true, CallingConvention=CallingConvention.StdCall)]
        public static extern bool OpenPrinter([MarshalAs(UnmanagedType.LPStr)] string szPrinter, out IntPtr hPrinter, IntPtr pd);
    
        [DllImport("winspool.Drv", EntryPoint="ClosePrinter", SetLastError=true, ExactSpelling=true, CallingConvention=CallingConvention.StdCall)]
        public static extern bool ClosePrinter(IntPtr hPrinter);
    
        [DllImport("winspool.Drv", EntryPoint="StartDocPrinterA", SetLastError=true, CharSet=CharSet.Ansi, ExactSpelling=true, CallingConvention=CallingConvention.StdCall)]
        public static extern bool StartDocPrinter( IntPtr hPrinter, Int32 level,  [In, MarshalAs(UnmanagedType.LPStruct)] DOCINFOA di);
    
        [DllImport("winspool.Drv", EntryPoint="EndDocPrinter", SetLastError=true, ExactSpelling=true, CallingConvention=CallingConvention.StdCall)]
        public static extern bool EndDocPrinter(IntPtr hPrinter);
    
        [DllImport("winspool.Drv", EntryPoint="StartPagePrinter", SetLastError=true, ExactSpelling=true, CallingConvention=CallingConvention.StdCall)]
        public static extern bool StartPagePrinter(IntPtr hPrinter);
    
        [DllImport("winspool.Drv", EntryPoint="EndPagePrinter", SetLastError=true, ExactSpelling=true, CallingConvention=CallingConvention.StdCall)]
        public static extern bool EndPagePrinter(IntPtr hPrinter);
    
        [DllImport("winspool.Drv", EntryPoint="WritePrinter", SetLastError=true, ExactSpelling=true, CallingConvention=CallingConvention.StdCall)]
        public static extern bool WritePrinter(IntPtr hPrinter, IntPtr pBytes, Int32 dwCount, out Int32 dwWritten );
    
        // SendBytesToPrinter()
        // When the function is given a printer name and an unmanaged array
        // of bytes, the function sends those bytes to the print queue.
        // Returns true on success, false on failure.
        public static bool SendBytesToPrinter( string szPrinterName, IntPtr pBytes, Int32 dwCount)
        {
            Int32    dwError = 0, dwWritten = 0;
            IntPtr    hPrinter = new IntPtr(0);
            DOCINFOA    di = new DOCINFOA();
            bool    bSuccess = false; // Assume failure unless you specifically succeed.
    
            di.pDocName = "My C#.NET RAW Document";
            di.pDataType = "RAW";
    
            // Open the printer.
            if( OpenPrinter( szPrinterName.Normalize(), out hPrinter, IntPtr.Zero ) )
            {
                // Start a document.
                if( StartDocPrinter(hPrinter, 1, di) )
                {
                    // Start a page.
                    if( StartPagePrinter(hPrinter) )
                    {
                        // Write your bytes.
                        bSuccess = WritePrinter(hPrinter, pBytes, dwCount, out dwWritten);
                        EndPagePrinter(hPrinter);
                    }
                    EndDocPrinter(hPrinter);
                }
                ClosePrinter(hPrinter);
            }
            // If you did not succeed, GetLastError may give more information
            // about why not.
            if( bSuccess == false )
            {
                    dwError = Marshal.GetLastWin32Error();
            }
            return bSuccess;
        }
    
        public static bool SendFileToPrinter( string szPrinterName, string szFileName )
        {
            // Open the file.
            FileStream fs = new FileStream(szFileName, FileMode.Open);
            // Create a BinaryReader on the file.
            BinaryReader br = new BinaryReader(fs);
            // Dim an array of bytes big enough to hold the file's contents.
            Byte []bytes = new Byte[fs.Length];
            bool bSuccess = false;
            // Your unmanaged pointer.
            IntPtr pUnmanagedBytes = new IntPtr(0);
            int nLength;
    
            nLength = Convert.ToInt32(fs.Length);
            // Read the contents of the file into the array.
            bytes = br.ReadBytes( nLength );
            // Allocate some unmanaged memory for those bytes.
            pUnmanagedBytes = Marshal.AllocCoTaskMem(nLength);
            // Copy the managed byte array into the unmanaged array.
            Marshal.Copy(bytes, 0, pUnmanagedBytes, nLength);
            // Send the unmanaged bytes to the printer.
            bSuccess = SendBytesToPrinter(szPrinterName, pUnmanagedBytes, nLength);
            // Free the unmanaged memory that you allocated earlier.
            Marshal.FreeCoTaskMem(pUnmanagedBytes);
            return bSuccess;
        }
        public static bool SendStringToPrinter( string szPrinterName, string szString )
        {
            IntPtr pBytes;
            Int32 dwCount;
            // How many characters are in the string?
            dwCount = szString.Length;
            // Assume that the printer is expecting ANSI text, and then convert
            // the string to ANSI text.
            pBytes = Marshal.StringToCoTaskMemAnsi(szString);
            // Send the converted ANSI string to the printer.
            SendBytesToPrinter(szPrinterName, pBytes, dwCount);
            Marshal.FreeCoTaskMem(pBytes);
            return true;
        }
    }
    					
  9. Press F5 to build, and then run the program.
  10. Click Button1 to load and print a file's contents.
  11. Click Button2 to print a string. (You may have to eject the page manually because the string is sent without the formfeed command.)

REFERENCES

For more information, click the following article numbers to view the articles in the Microsoft Knowledge Base:
138594 How to send raw data to a printer by using the Win32 API

Properties

Article ID: 322091 - Last Review: May 9, 2006 - Revision: 5.0
APPLIES TO
  • Microsoft .NET Framework Software Development Kit 1.0 Service Pack 2
  • Microsoft Windows XP Professional
  • the operating system: Microsoft Windows XP 64-Bit Edition
Keywords: 
kbhowtomaster kbdswgdi2003swept KB322091

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