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Sending Data to LPT1

Posted on 2006-07-21
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Last Modified: 2007-12-19
I am trying to send data to the LPT port for a label printer.
I am using VB.NET-VS2005
I have tried several things and none of them are working, and am running out of forums to ask.

The following is what I have tried:

*********1
FileOpen(1, "LPT1", OpenMode.Output)
PrintLine(1, "data")
FileClose(1)
--Got an error about tape drives and other devices and not to use
\\.\

*********2
FileOpen(1, "C:\TEMP\label.txt", OpenMode.Output)
PrintLine(1, "data")
FileClose(1)
Shell("C:\Windows\System32\Command.com Copy C:\TEMP\Label.txt LPT1:")

This created a file, but I need to copy it to the LPT port.
THe copy command works through windows command window,
but fails  with the shell command in VB.NET.

I am in need of a solution, I have been searching the internet all day for a solution.
Any help would be greatly appreciated.
0
Comment
Question by:kpaubel
9 Comments
 
LVL 5

Expert Comment

by:Davidshc76
ID: 17158830

Private Sub Command1_Click()
PrintThisFile "C:\welcome.txt"
End Sub

Public Sub PrintThisFile(FileName As String)
    On Error Resume Next
    Dim X As Long
    x= ShellExecute(me.hWnd, "Print", FileName, vbNullString, vbNullString, SW_SHOWMAXIMIZED)
End Sub
0
 

Author Comment

by:kpaubel
ID: 17159703
I am using VB.NET-VS2005, not vb 6. I can get it working by starting up a process
and using notepad to print. I would rather go directly to the LPT port as this is the preferred method. I can see samples on the internet for the COM ports, but when I try to utilize the LPT port it fails.

0
 
LVL 28

Expert Comment

by:iboutchkine
ID: 17167309
try this


Imports System.IO
Imports System.Drawing.Printing
Imports System.Runtime.InteropServices

Public Class Form1
    Inherits System.Windows.Forms.Form


    ' Click event handler for a button - designed to show how to use the
    ' SendFileToPrinter and SendBytesToPrinter functions.
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        ' Allow the user to select a file.
        Dim ofd As New OpenFileDialog()
        If ofd.ShowDialog(Me) Then
            ' Allow the user to select a printer.
            Dim pd As New PrintDialog()
            pd.PrinterSettings = New PrinterSettings()
            If pd.ShowDialog(Me) Then
                ' Print the file to the printer.
                RawPrinterHelper.SendFileToPrinter(pd.PrinterSettings.PrinterName, ofd.FileName)
            End If
        End If
    End Sub ' Button1_Click()

    ' Click event handler for a button - designed to show how to use the
    ' SendBytesToPrinter function to send a string to the printer.
    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        Dim s As String
        Dim pd As New PrintDialog()

        ' You need a string to send.
        s = "         Hello, this is a test" & vbCrLf
        s &= "         Second line"
        ' Open the printer dialog box, and then allow the user to select a printer.
        pd.PrinterSettings = New PrinterSettings()
        If pd.ShowDialog(Me) Then
            RawPrinterHelper.SendStringToPrinter(pd.PrinterSettings.PrinterName, s)
        End If

        ' a new page
        s = "         second line" & vbCrLf
        RawPrinterHelper.SendStringToPrinter(pd.PrinterSettings.PrinterName, s)

    End Sub ' Button2_Click()

End Class


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
    <DllImport("kernel32.dll", EntryPoint:="GetLastError", _
       SetLastError:=True, CharSet:=CharSet.Unicode, _
       ExactSpelling:=True, CallingConvention:=CallingConvention.StdCall)> _
    Public Shared Function GetLastError() As Int32
    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 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 = GetLastError()
        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)
        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)
        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)
    End Function
End Class
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Author Comment

by:kpaubel
ID: 17175964
In the routine SendBytestoPrinter at the OpenPrinter line I am receiving the follwoing error

A call to PInvoke function 'InventoryManager!InventoryManager.RawPrinterHelper::OpenPrinter' has unbalanced the stack. This is likely because the managed PInvoke signature does not match the unmanaged target signature. Check that the calling convention and parameters of the PInvoke signature match the target unmanaged signature.

0
 
LVL 5

Expert Comment

by:Davidshc76
ID: 17182023

Shell(String.Format("c:\command.com /c copy {0} lpt1", fileName))

uses XP to print

http://www.planet-source-code.com/vb/scripts/ShowCode.asp?txtCodeId=3791&lngWId=10
0
 

Author Comment

by:kpaubel
ID: 17201491
Thanks all for your posts on this. I have found a simpler soloution with much less code. Just in case anyone else is following this and wants to view the solution I found, you can view it at

https://support.zebra.com/cpws/docs/zpl/zpl_elp_vbnet.htm

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