HOWTO: Retrieve Settings From a Printer Driver

ID: Q190218


The information in this article applies to:
  • Microsoft Visual Basic Learning, Professional, and Enterprise Editions for Windows, versions 5.0, 6.0
  • Microsoft Visual Basic Standard, Professional, and Enterprise Editions, 32-bit only, for Windows, version 4.0


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, pDevModeInput As Any, 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) Then
             nSize = DocumentProperties(NULLPTR, hPrinter, szPrinterName, _
             NULLPTR, NULLPTR, 0)
             ReDim aDevMode(1 To nSize)
             nSize = DocumentProperties(NULLPTR, hPrinter, szPrinterName, _
             aDevMode(1), NULLPTR, DM_OUT_BUFFER)
             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.

Additional query words:

Keywords : kbAPI kbPrinting kbSDKWin32 kbVBp kbVBp400 kbVBp500 kbVBp600 kbGrpVB kbDSupport
Version : WINDOWS:4.0,5.0,6.0
Platform : WINDOWS
Issue type : kbhowto


Last Reviewed: January 5, 2000
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