Credit: The class file below is from http://support.microsoft.com/kb/322090
Important: The original class contains a bug in the SendFileToPrinter method that may cause problems. It fails to close the file send to the printer, meaning you will get locking errors if you repeatedly create and print the same spoolfile in a single module. The patch inserted in the orinal class is:
' --- start patch
fs.close
' --- end patchYou need to manyaly patch this issue if you copy/paste the code from the MS Support website.
The class enables you to send either files or strings of bytes as raw data to the printer. To use the class you need the following imports
Imports System.IO
Imports System.Drawing.Printing
Imports System.Runtime.InteropServices
Calling the class in it's basic form is extremely simple:
Sending a file named "direct.dat" to the printer named "HP Laserjet 5" on your system:
dim s_printername as string = "HP Laserjet 5"
dim s_filename as string = "direct.dat"
rawprinterhelper.sendfiletoprinter(s_printername,s_filename)
Examples including some error checking and selecting a printer can be found on the url mentioned at the top of the article.
Usage:
- Copy/paste theimports to the very top of the module you will put the class in
- Copy/paste the class below in the module
- Call the rawprinterhelper.sendfiletoprinter from your code
#Region "class_RawPrinterHelper http://support.microsoft.com/kb/322090"
Public Class RawPrinterHelper
' Structure and API declarions:
<StructLayout(LayoutKind.Sequential, CharSet:=CharSet.Unicode)> _
Structure DOCINFOW
<MarshalAs(UnmanagedType.LPWStr)> Public pDocName As String
<MarshalAs(UnmanagedType.LPWStr)> Public pOutputFile As String
<MarshalAs(UnmanagedType.LPWStr)> Public pDataType As String
End Structure
<DllImport("winspool.Drv", EntryPoint:="OpenPrinterW", _
SetLastError:=True, CharSet:=CharSet.Unicode, _
ExactSpelling:=True, CallingConvention:=CallingConvention.StdCall)> _
Public Shared Function OpenPrinter(ByVal src As String, ByRef hPrinter As IntPtr, ByVal pd As Long) As Boolean
End Function
<DllImport("winspool.Drv", EntryPoint:="ClosePrinter", _
SetLastError:=True, CharSet:=CharSet.Unicode, _
ExactSpelling:=True, CallingConvention:=CallingConvention.StdCall)> _
Public Shared Function ClosePrinter(ByVal hPrinter As IntPtr) As Boolean
End Function
<DllImport("winspool.Drv", EntryPoint:="StartDocPrinterW", _
SetLastError:=True, CharSet:=CharSet.Unicode, _
ExactSpelling:=True, CallingConvention:=CallingConvention.StdCall)> _
Public Shared Function StartDocPrinter(ByVal hPrinter As IntPtr, ByVal level As Int32, ByRef pDI As DOCINFOW) As Boolean
End Function
<DllImport("winspool.Drv", EntryPoint:="EndDocPrinter", _
SetLastError:=True, CharSet:=CharSet.Unicode, _
ExactSpelling:=True, CallingConvention:=CallingConvention.StdCall)> _
Public Shared Function EndDocPrinter(ByVal hPrinter As IntPtr) As Boolean
End Function
<DllImport("winspool.Drv", EntryPoint:="StartPagePrinter", _
SetLastError:=True, CharSet:=CharSet.Unicode, _
ExactSpelling:=True, CallingConvention:=CallingConvention.StdCall)> _
Public Shared Function StartPagePrinter(ByVal hPrinter As IntPtr) As Boolean
End Function
<DllImport("winspool.Drv", EntryPoint:="EndPagePrinter", _
SetLastError:=True, CharSet:=CharSet.Unicode, _
ExactSpelling:=True, CallingConvention:=CallingConvention.StdCall)> _
Public Shared Function EndPagePrinter(ByVal hPrinter As IntPtr) As Boolean
End Function
<DllImport("winspool.Drv", EntryPoint:="WritePrinter", _
SetLastError:=True, CharSet:=CharSet.Unicode, _
ExactSpelling:=True, CallingConvention:=CallingConvention.StdCall)> _
Public Shared Function WritePrinter(ByVal hPrinter As IntPtr, ByVal pBytes As IntPtr, ByVal dwCount As Int32, ByRef dwWritten As Int32) As Boolean
End Function
' 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 or False on failure.
Public Shared Function SendBytesToPrinter(ByVal szPrinterName As String, ByVal pBytes As IntPtr, ByVal dwCount As Int32) As Boolean
Dim hPrinter As IntPtr ' The printer handle.
Dim dwError As Int32 ' Last error - in case there was trouble.
Dim di As New DOCINFOW ' Describes your document (name, port, data type).
Dim dwWritten As Int32 ' The number of bytes written by WritePrinter().
Dim bSuccess As Boolean ' Your success code.
' Set up the DOCINFO structure.
With di
.pDocName = "My Visual Basic .NET RAW Document"
.pDataType = "RAW"
End With
' Assume failure unless you specifically succeed.
bSuccess = False
If OpenPrinter(szPrinterName, hPrinter, 0) Then
If StartDocPrinter(hPrinter, 1, di) Then
If StartPagePrinter(hPrinter) Then
' Write your printer-specific bytes to the printer.
bSuccess = WritePrinter(hPrinter, pBytes, dwCount, dwWritten)
EndPagePrinter(hPrinter)
End If
EndDocPrinter(hPrinter)
End If
ClosePrinter(hPrinter)
End If
' If you did not succeed, GetLastError may give more information
' about why not.
If bSuccess = False Then
dwError = Marshal.GetLastWin32Error()
End If
Return bSuccess
End Function ' SendBytesToPrinter()
' SendFileToPrinter()
' When the function is given a file name and a printer name,
' the function reads the contents of the file and sends the
' contents to the printer.
' Presumes that the file contains printer-ready data.
' Shows how to use the SendBytesToPrinter function.
' Returns True on success or False on failure.
Public Shared Function SendFileToPrinter(ByVal szPrinterName As String, ByVal szFileName As String) As Boolean
' Open the file.
Dim fs As New FileStream(szFileName, FileMode.Open)
' Create a BinaryReader on the file.
Dim br As New BinaryReader(fs)
' Dim an array of bytes large enough to hold the file's contents.
Dim bytes(fs.Length) As Byte
Dim bSuccess As Boolean
' Your unmanaged pointer.
Dim pUnmanagedBytes As IntPtr
' Read the contents of the file into the array.
bytes = br.ReadBytes(fs.Length)
' Allocate some unmanaged memory for those bytes.
pUnmanagedBytes = Marshal.AllocCoTaskMem(fs.Length)
' Copy the managed byte array into the unmanaged array.
Marshal.Copy(bytes, 0, pUnmanagedBytes, fs.Length)
' Send the unmanaged bytes to the printer.
bSuccess = SendBytesToPrinter(szPrinterName, pUnmanagedBytes, fs.Length)
' Free the unmanaged memory that you allocated earlier.
Marshal.FreeCoTaskMem(pUnmanagedBytes)
' --- start patch
fs.close
' --- end patch
Return bSuccess
End Function ' SendFileToPrinter()
' When the function is given a string and a printer name,
' the function sends the string to the printer as raw bytes.
Public Shared Function SendStringToPrinter(ByVal szPrinterName As String, ByVal szString As String) As Integer
Dim pBytes As IntPtr
Dim dwCount As Int32
' 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 1
End Function
End Class
#End Region