Try this:
using System;
using System.Drawing;
using System.Drawing.Printing;
using System.IO;
using System.Runtime.InteropServices;
using System.Windows.Forms;
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?
// Fix from Nicholas Piasecki:
// dwCount = szString.Length;
dwCount = (szString.Length + 1) * Marshal.SystemMaxDBCSCharSize;
// 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;
}
}