How To Retrieve Settings From a Printer Driver (190218)


The information in this article applies to:

  • Microsoft Visual Basic Learning Edition for Windows 5.0
  • Microsoft Visual Basic Learning Edition for Windows 6.0
  • Microsoft Visual Basic Professional Edition for Windows 5.0
  • Microsoft Visual Basic Professional Edition for Windows 6.0
  • Microsoft Visual Basic Enterprise Edition for Windows 5.0
  • Microsoft Visual Basic Enterprise Edition for Windows 6.0
  • Microsoft Visual Basic Standard Edition, 32-bit, for Windows 4.0
  • Microsoft Visual Basic Professional Edition, 32-bit, for Windows 4.0
  • Microsoft Visual Basic Enterprise Edition, 32-bit, for Windows 4.0
This article was previously published under Q190218

SUMMARY

The Visual Basic Printer object allows you to get to many of a printer driver's properties, but it does not give you access to all of them. The following sample demonstrates how to retrieve information from a printer driver using the WIN32 API.

MORE INFORMATION

A printer's settings are stored in a structure called the DEVMODE. This sample retrieves the DEVMODE for the current default printer and displays its settings in a ListBox. Note that these are numeric values that must be compared to constants to determine their meaning. This article only includes the constants for the values the code actually displays. Other constants can be found in the REFERENCES section at the end of this article.

The sample below contains two custom functions, StripNulls and ByteToString. StripNulls simply takes a String and removes all characters starting at the first Null. This is used in place of the RTrim function because in Visual Basic 5.0, fixed-length strings are padded with Nulls instead of the spaces used in Visual Basic 4.0. The ByteToString function converts an array of Bytes into a String. The DEVMODE contains two such arrays.

There are two special notes about the following sample when running under Windows NT. First, many monochrome drivers have their dmColor property set to 2, which means they report being capable of color printing, but really are not. Also, some settings for the "Generic / Text Only" printer driver may not be accurate under NT.

Step-by-Step Example

  1. Open a new Standard EXE project. Form1 is created by default.
  2. Add a CommandButton and a ListBox to the Form.
  3. Add the following code to the Form's module:
          Option Explicit

      Private Const NULLPTR = 0&
      ' Constants for DEVMODE
      Private Const CCHDEVICENAME = 32
      Private Const CCHFORMNAME = 32
      ' Constants for DocumentProperties
      Private Const DM_MODIFY = 8
      Private Const DM_COPY = 2
      Private Const DM_IN_BUFFER = DM_MODIFY
      Private Const DM_OUT_BUFFER = DM_COPY
      ' Constants for dmOrientation
      Private Const DMORIENT_PORTRAIT = 1
      Private Const DMORIENT_LANDSCAPE = 2
      ' Constants for dmPrintQuality
      Private Const DMRES_DRAFT = (-1)
      Private Const DMRES_HIGH = (-4)
      Private Const DMRES_LOW = (-2)
      Private Const DMRES_MEDIUM = (-3)
      ' Constants for dmTTOption
      Private Const DMTT_BITMAP = 1
      Private Const DMTT_DOWNLOAD = 2
      Private Const DMTT_DOWNLOAD_OUTLINE = 4
      Private Const DMTT_SUBDEV = 3
      ' Constants for dmColor
      Private Const DMCOLOR_COLOR = 2
      Private Const DMCOLOR_MONOCHROME = 1
      ' Constants for dmCollate
      Private Const DMCOLLATE_FALSE = 0
      Private Const DMCOLLATE_TRUE = 1
      Private Const DM_COLLATE As Long = &H8000
      ' Constants for dmDuplex
      Private Const DM_DUPLEX = &H1000&
      Private Const DMDUP_HORIZONTAL = 3
      Private Const DMDUP_SIMPLEX = 1
      Private Const DMDUP_VERTICAL = 2

      Private Type DEVMODE
          dmDeviceName(1 To CCHDEVICENAME) As Byte
          dmSpecVersion As Integer
          dmDriverVersion As Integer
          dmSize As Integer
          dmDriverExtra As Integer
          dmFields As Long
          dmOrientation As Integer
          dmPaperSize As Integer
          dmPaperLength As Integer
          dmPaperWidth As Integer
          dmScale As Integer
          dmCopies As Integer
          dmDefaultSource As Integer
          dmPrintQuality As Integer
          dmColor As Integer
          dmDuplex As Integer
          dmYResolution As Integer
          dmTTOption As Integer
          dmCollate As Integer
          dmFormName(1 To CCHFORMNAME) As Byte
          dmUnusedPadding As Integer
          dmBitsPerPel As Integer
          dmPelsWidth As Long
          dmPelsHeight As Long
          dmDisplayFlags As Long
          dmDisplayFrequency As Long
                
      End Type

      Private Declare Function OpenPrinter Lib "winspool.drv" Alias _
      "OpenPrinterA" (ByVal pPrinterName As String, phPrinter As Long, _
      ByVal pDefault As Long) As Long

      Private Declare Function DocumentProperties Lib "winspool.drv" _ 
      Alias "DocumentPropertiesA" (ByVal hwnd As Long, _ 
      ByVal hPrinter As Long, ByVal pDeviceName As String, _ 
      pDevModeOutput As Any, ByVal pDevModeInput As Long, _ ByVal fMode As Long)
      As Long      

      Private Declare Function ClosePrinter Lib "winspool.drv" _
      (ByVal hPrinter As Long) As Long

      Private Declare Sub CopyMemory Lib "KERNEL32" Alias "RtlMoveMemory" _
      (hpvDest As Any, hpvSource As Any, ByVal cbCopy As Long)

      Function StripNulls(OriginalStr As String) As String
         If (InStr(OriginalStr, Chr(0)) > 0) Then
            OriginalStr = Left(OriginalStr, InStr(OriginalStr, Chr(0)) - 1)
         End If
         StripNulls = Trim(OriginalStr)
      End Function

      Function ByteToString(ByteArray() As Byte) As String
        Dim TempStr As String
        Dim I As Integer

        For I = 1 To CCHDEVICENAME
            TempStr = TempStr & Chr(ByteArray(I))
        Next I
        ByteToString = StripNulls(TempStr)
      End Function

      Function GetPrinterSettings(szPrinterName As String, hdc As Long) _
      As Boolean
      Dim hPrinter As Long
      Dim nSize As Long
      Dim pDevMode As DEVMODE
      Dim aDevMode() As Byte
      Dim TempStr As String

        If OpenPrinter(szPrinterName, hPrinter, NULLPTR) <> 0 Then
           nSize = DocumentProperties(NULLPTR, hPrinter, szPrinterName, _
           NULLPTR, NULLPTR, 0)
          If nSize < 1 Then
            GetPrinterSettings = False
            Exit Function
          End If
          ReDim aDevMode(1 To nSize)
          nSize = DocumentProperties(NULLPTR, hPrinter, szPrinterName, _
          aDevMode(1), NULLPTR, DM_OUT_BUFFER)
          If nSize < 0 Then
            GetPrinterSettings = False
            Exit Function
          End If
         Call CopyMemory(pDevMode, aDevMode(1), Len(pDevMode))


         List1.Clear   ' empty the ListBox
         List1.AddItem "Printer Name: " & _
         ByteToString(pDevMode.dmDeviceName)

         If pDevMode.dmOrientation = DMORIENT_PORTRAIT Then
            TempStr = "PORTRAIT"
         ElseIf pDevMode.dmOrientation = DMORIENT_LANDSCAPE Then
            TempStr = "LANDSCAPE"
         Else
            TempStr = "UNDEFINED"
         End If
         List1.AddItem "Orientation: " & TempStr

         Select Case pDevMode.dmPrintQuality
            Case DMRES_DRAFT
                TempStr = "DRAFT"
            Case DMRES_HIGH
                TempStr = "HIGH"
            Case DMRES_LOW
                TempStr = "LOW"
            Case DMRES_MEDIUM
                TempStr = "MEDIUM"
            Case Else   ' positive value
                TempStr = CStr(pDevMode.dmPrintQuality) & " dpi"
         End Select
         List1.AddItem "Print Quality: " & TempStr

         Select Case pDevMode.dmTTOption
            Case DMTT_BITMAP    ' default for dot-matrix printers
                TempStr = "TrueType fonts as graphics"
            Case DMTT_DOWNLOAD  ' default for HP printers that use PCL
                TempStr = "Downloads TrueType fonts as soft fonts"
            Case DMTT_SUBDEV    ' default for PostScript printers
                TempStr = "Substitute device fonts for TrueType fonts"
            Case Else
                TempStr = "UNDEFINED"
         End Select
         List1.AddItem "TrueType Option: " & TempStr

         ' Windows NT drivers often return COLOR from Monochrome printers
         If pDevMode.dmColor = DMCOLOR_MONOCHROME Then
            TempStr = "MONOCHROME"
         ElseIf pDevMode.dmColor = DMCOLOR_COLOR Then
            TempStr = "COLOR"
         Else
            TempStr = "UNDEFINED"
         End If
         List1.AddItem "Color or Monochrome: " & TempStr

         If pDevMode.dmScale = 0 Then
            TempStr = "NONE"
         Else
            TempStr = CStr(pDevMode.dmScale)
         End If
         List1.AddItem "Scale Factor: " & TempStr

        If pDevMode.dmFields And DM_COLLATE Then
            If pDevMode.dmCollate = DMCOLLATE_FALSE Then
               TempStr = "Collating is supported, but turned off"
            ElseIf pDevMode.dmCollate = DMCOLLATE_TRUE Then
               TempStr = "Collating is supported and turned on"
            End If
         Else
            TempStr = "Collating is unsupported"
         End If
         List1.AddItem TempStr        
         If pDevMode.dmFields And DM_DUPLEX Then
            If pDevMode.dmDuplex = DMDUP_SIMPLEX Then
               TempStr = "Duplex is supported, but turned off (1)"
            ElseIf pDevMode.dmDuplex = DMDUP_VERTICAL Then
               TempStr = "Duplex is set to VERTICAL (2)"
            ElseIf pDevMode.dmDuplex = DMDUP_HORIZONTAL Then
               TempStr = "Duplex is set to HORIZONTAL (3)"
            Else
               TempStr = "Duplex is set to undefined value of " & _
                  pDevMode.dmDuplex
            End If
         Else
            TempStr = "Duplex is unsupported"
         End If
         List1.AddItem TempStr

         List1.AddItem "Y Resolution: " & pDevMode.dmYResolution & " dpi"
         List1.AddItem "Copies: " & CStr(pDevMode.dmCopies)
         ' Add any other items of interest ...

         Call ClosePrinter(hPrinter)
         GetPrinterSettings = True
      Else
         GetPrinterSettings = False
      End If
      End Function

      Private Sub Command1_Click()
      If GetPrinterSettings(Printer.DeviceName, Printer.hdc) = False Then
         List1.AddItem "No Settings Retrieved!"
         MsgBox "Unable to retrieve Printer settings.", , "Failure"
      End If
      End Sub
  4. Run the project and click on Command1. The current default printer's settings will be displayed in the ListBox.

REFERENCES

To find additional constants, please search on DEVMODE in either the Win32 Programmer's Reference or the Microsoft Developer Network (MSDN) Library CD-ROM.
Modification Type:MinorLast Reviewed:7/14/2004
Keywords:kbAPI kbhowto kbprint KB190218
©2004 Microsoft Corporation. All rights reserved.