Tip 93: Retrieving the Names of Installed Printers

May 22, 1995

Abstract

The Windows® initialization file, WIN.INI, contains a list of all printers attached to the computer system. This article contains an example program that retrieves the name of each printer stored in the WIN.INI initialization file.

Using GetProfileString and GetPrivateProfileString

The Devices section of the WIN.INI initialization file contains the names of all printers attached to your computer system. You can retrieve this list of printer names by using two Windows® application programming interface (API) functions.

The Windows API GetProfileString and GetPrivateProfileString functions can be used to retrieve the name of a printer as stored in the WIN.INI file. For a complete discussion of these functions, see the articles listed in the "Additional References" section of this article.

Example Program

This program retrieves the names of all installed printers from the WIN.INI initialization file. The printer names are displayed in a List Box control.

  1. Create a new project in Visual Basic. Form1 is created by default.

  2. Add the following Constant, Declare, and Type statements to the General Declarations section of Form1 (note that each Declare statement must be typed as a single line of text):
    Option Explicit
Private Type WindowsDevice
   WindowsDeviceUserName As String
   WindowsDeviceShortName As String
   WindowsDevicePortName As String
End Type
Private Declare Function GetProfileString Lib "Kernel" (ByVal lpAppName 
   As String, ByVal lpKeyName As String, ByVal lpDefault As String, ByVal 
   lpReturnedString As String, ByVal nSize As Integer) As Integer
Private Declare Function GetPrivateProfileString Lib "Kernel" (ByVal lpAppName 
   As String, ByVal lpKeyName As String, ByVal lpDefault As String, ByVal 
   lpReturnedString As String, ByVal nSize As Integer, ByVal lpFileName As 
   String) As Integer
Private Declare Function GetProfileKeys Lib "Kernel" Alias "GetProfileString" 
   (ByVal lpAppName As String, ByVal lpKeyName As Long, ByVal lpDefault As 
    String, ByVal lpReturnedString As String, ByVal nSize As Integer) As Integer
Private Declare Function GetPrivateProfileKeys Lib "Kernel" Alias 
   "GetPrivateProfileString" (ByVal lpAppName As String, ByVal lpKeyName As 
   Long, ByVal lpDefault As String, ByVal lpReturnedString As String, ByVal 
   nSize As Integer, ByVal lpFileName As String) As Integer
Const WINDOWS_SECTION_NAME = "windows"
Const DEVICES_SECTION_NAME = "devices"
Const DEVICE_KEY_NAME = "device"
Const NO_PRINTER = "(none)"
  3. Add a Text Box control to Form1. Text1 is created by default.

  4. Add a Command Button control to Form1. Command1 is created by default.

  5. Add the following code to the Click event for Command1 (note that the List1.AddItem statement must be typed as a single line of code):
    Private Sub Command1_Click()
Dim OrgPrinter As WindowsDevice
Call GetDefaultPrinter(OrgPrinter)
Text1.Text = OrgPrinter.WindowsDeviceUserName

Dim NumPrinters As Integer
ReDim InstalledPrinters(0) As WindowsDevice
Call GetInstalledPrinters(InstalledPrinters())
For NumPrinters = 1 To UBound(InstalledPrinters)
List1.AddItem InstalledPrinters(NumPrinters).WindowsDeviceUserName + " 
on " + InstalledPrinters(NumPrinters).WindowsDevicePortName
Next
List1.AddItem NO_PRINTER, 0
End Sub
  6. Create a new function called GetDefaultPrinter. Add the following code to this function:
    Private Sub GetDefaultPrinter(recDefaultPrinter As WindowsDevice)
Dim StrPos As Integer
Dim DefaultPrinter As String
Dim RC As Integer
DefaultPrinter = GetString(WINDOWS_SECTION_NAME, DEVICE_KEY_NAME, "", "")
StrPos = InStr(DefaultPrinter, ",")
recDefaultPrinter.WindowsDeviceUserName = Left$(DefaultPrinter, StrPos - 1)
DefaultPrinter = Mid$(DefaultPrinter, StrPos + 1)
StrPos = InStr(DefaultPrinter, ",")
recDefaultPrinter.WindowsDeviceShortName = Left$(DefaultPrinter, StrPos - 1)
recDefaultPrinter.WindowsDevicePortName = Mid$(DefaultPrinter, StrPos + 1)
End Sub
  7. Create a new function called GetInstalledPrinter. Add the following code to this function (note that the InstalledPrinter lines must be typed as a single line of code):
    Private Sub GetInstalledPrinters(recInstalledPrinters() As WindowsDevice)
Dim StrPos As Integer
Dim PrtSub As Integer
Dim InstalledPrinter As String
ReDim PrinterNames(0) As String
Call GetKeyNames(DEVICES_SECTION_NAME, PrinterNames(), "")
ReDim recInstalledPrinters(UBound(PrinterNames))
For PrtSub = 1 To UBound(PrinterNames)
InstalledPrinter = GetString(DEVICES_SECTION_NAME, PrinterNames(PrtSub), 
"", "")
StrPos = InStr(InstalledPrinter, ",")
recInstalledPrinters(PrtSub).WindowsDeviceUserName = 
PrinterNames(PrtSub)
recInstalledPrinters(PrtSub).WindowsDeviceShortName = 
Left$(InstalledPrinter, StrPos - 1)
InstalledPrinter = Mid$(InstalledPrinter, StrPos + 1)
StrPos = InStr(InstalledPrinter, ",")
If StrPos > 0 Then
recInstalledPrinters(PrtSub).WindowsDevicePortName = 
Left$(InstalledPrinter, StrPos - 1)
Else
recInstalledPrinters(PrtSub).WindowsDevicePortName = 
InstalledPrinter
End If
Next
End Sub
  8. Create a new function called GetString. Add the following code to this function (note that the Function and KeyValueLength lines must each be typed as a single line of code):
    Function GetString(SectionName As String, KeyName As String, DefaultValue 
As String, ProfileName As String) As String
Dim KeyValueLength As Integer
Dim KeyValue As String
KeyValue = Space$(256)
If Trim$(ProfileName) = "" Then
KeyValueLength = GetProfileString(SectionName, KeyName, DefaultValue, 
KeyValue, Len(KeyValue))
Else
KeyValueLength = GetPrivateProfileString(SectionName, KeyName, 
DefaultValue, KeyValue, Len(KeyValue), ProfileName)
End If
GetString = Left$(KeyValue, KeyValueLength)
End Function
  9. Create a new function called GetKeyName. Add the following code to this function (note that the Sub and KeyNamesLength lines must each be typed as a single line of code):
    Sub GetKeyNames(SectionName As String, KeyNames() As String, ProfileName 
   As String)
    Dim StrPos As Integer
    Dim KeyCount As Integer
    Dim Start As Integer
    Dim KeyNamesLength As Integer
    Dim KeyNameString As String
    KeyNameString = Space$(1024)
    If Trim$(ProfileName) = "" Then
        KeyNamesLength = GetProfileKeys(SectionName, 0, "", KeyNameString, 
            Len(KeyNameString))
    Else
        KeyNamesLength = GetPrivateProfileKeys(SectionName, 0, "", 
            KeyNameString, Len(KeyNameString), ProfileName)
    End If
    KeyCount = 0
    ReDim KeyNames(0)
    If KeyNamesLength > 0 Then
        KeyNameString = Left$(KeyNameString, KeyNamesLength)
        If Right$(KeyNameString, 1) <> Chr$(0) Then
            KeyNameString = KeyNameString + Chr$(0)
        End If
        KeyNamesLength = Len(KeyNameString)
        Start = 1
        Do
            StrPos = InStr(Start, KeyNameString, Chr$(0))
            If StrPos > 0 Then
                KeyCount = KeyCount + 1
                ReDim Preserve KeyNames(KeyCount)
                KeyNames(KeyCount) = Mid$(KeyNameString, Start, StrPos - Start)
                If StrPos < KeyNamesLength Then
                    Start = StrPos + 1
                Else
                    Exit Do
                End If
            Else
                Exit Do
            End If
        Loop
        End If
End Sub

Run the example program by pressing the F5 function key. Click the Command Button control. The name of the default printer is displayed in the Text Box control, and a list of all installed printers is displayed in the List Box control.

Additional References

Knowledge Base Q105839. "Changing WIN.INI Printer Settings from VB using Windows API."

"Accessing Initialization Files." (MSDN Library, Periodicals)

"Querying Windows for Printer Information." (MSDN Library, Periodicals)

"Tip #30: Retrieving the Default Printer's Name from WIN.INI."