Excel – Trouble listing printers with Excel VBA

excelprintingvba

So here's the original problem:

I have an Excel file with a button that runs a macro. This macro needs to print the sheet to 2 separate network printers. The workbook will be run on multiple different computers on the network.

My current code looks like so:

Application.ActivePrinter = "Printer-A on Ne02:"
ActiveWindow.SelectedSheets.PrintOut Copies:=1, Collate:=True, IgnorePrintAreas:=False
Application.ActivePrinter = "Printer-B on Ne05:"
ActiveWindow.SelectedSheets.PrintOut Copies:=1, Collate:=True, IgnorePrintAreas:=False

The problem lies with the on Ne02: and on Ne05:. These values differ from one computer to another. E.g.:

Printer-A on Ne03:
Printer-B on Ne02:
Printer-A on Ne07:
etc

I can circumvent the issue by displaying the "select a printer" dialog and forcing users to choose the printer manually, but I would prefer for this to be automatic.

I have tried using the Windows Script Host Object Model to list all of the printers like so:

Function FindPrinter(name As String)
    Dim nwo As New WshNetwork
    Dim i As Integer
    Dim fullName As String

    For i = 0 To (nwo.EnumPrinterConnections.Count / 2) - 1
        If InStr(nwo.EnumPrinterConnections(i * 2 + 1), name) > 0 Then
            fullName = nwo.EnumPrinterConnections(i * 2 + 1)
        End If
    Next i

    ' Returns the LAST printer that matches
    FindPrinter = fullName
End Function

Sub MyMacro()
    ActivePrinter = FindPrinter("Printer-A")
End Sub

However this fails. If I look at the output of FindPrinter, it's only returning the string "Printer-A" without the "on Ne02:"

How can I get a full list of printers installed, including this "on NeXX:" bit? Or, alternatively, how can I set a printer as active knowing only its name?

Best Answer

Run the Test sub at the bottom:

Option Explicit
Private Const HKEY_CURRENT_USER As Long = &H80000001
Private Const HKCU = HKEY_CURRENT_USER
Private Const KEY_QUERY_VALUE = &H1&
Private Const ERROR_NO_MORE_ITEMS = 259&
Private Const ERROR_MORE_DATA = 234

Private Declare Function RegOpenKeyEx Lib "advapi32" _
    Alias "RegOpenKeyExA" ( _
    ByVal HKey As Long, _
    ByVal lpSubKey As String, _
    ByVal ulOptions As Long, _
    ByVal samDesired As Long, _
    phkResult As Long) As Long

Private Declare Function RegEnumValue Lib "advapi32.dll" _
    Alias "RegEnumValueA" ( _
    ByVal HKey As Long, _
    ByVal dwIndex As Long, _
    ByVal lpValueName As String, _
    lpcbValueName As Long, _
    ByVal lpReserved As Long, _
    lpType As Long, _
    lpData As Byte, _
    lpcbData As Long) As Long

Private Declare Function RegCloseKey Lib "advapi32.dll" ( _
    ByVal HKey As Long) As Long

Public Function GetPrinterFullNames() As String()
Dim Printers() As String ' array of names to be returned
Dim PNdx As Long    ' index into Printers()
Dim HKey As Long    ' registry key handle
Dim Res As Long     ' result of API calls
Dim Ndx As Long     ' index for RegEnumValue
Dim ValueName As String ' name of each value in the printer key
Dim ValueNameLen As Long    ' length of ValueName
Dim DataType As Long        ' registry value data type
Dim ValueValue() As Byte    ' byte array of registry value value
Dim ValueValueS As String   ' ValueValue converted to String
Dim CommaPos As Long        ' position of comma character in ValueValue
Dim ColonPos As Long        ' position of colon character in ValueValue
Dim M As Long               ' string index

' registry key in HCKU listing printers
Const PRINTER_KEY = "Software\Microsoft\Windows NT\CurrentVersion\Devices"

PNdx = 0
Ndx = 0
' assume printer name is less than 256 characters
ValueName = String$(256, Chr(0))
ValueNameLen = 255
' assume the port name is less than 1000 characters
ReDim ValueValue(0 To 999)
' assume there are less than 1000 printers installed
ReDim Printers(1 To 1000)

' open the key whose values enumerate installed printers
Res = RegOpenKeyEx(HKCU, PRINTER_KEY, 0&, _
    KEY_QUERY_VALUE, HKey)
' start enumeration loop of printers
Res = RegEnumValue(HKey, Ndx, ValueName, _
    ValueNameLen, 0&, DataType, ValueValue(0), 1000)
' loop until all values have been enumerated
Do Until Res = ERROR_NO_MORE_ITEMS
    M = InStr(1, ValueName, Chr(0))
    If M > 1 Then
        ' clean up the ValueName
        ValueName = Left(ValueName, M - 1)
    End If
    ' find position of a comma and colon in the port name
    CommaPos = InStr(1, ValueValue, ",")
    ColonPos = InStr(1, ValueValue, ":")
    ' ValueValue byte array to ValueValueS string
    On Error Resume Next
    ValueValueS = Mid(ValueValue, CommaPos + 1, ColonPos - CommaPos)
    On Error GoTo 0
    ' next slot in Printers
    PNdx = PNdx + 1
    Printers(PNdx) = ValueName & " on " & ValueValueS
    ' reset some variables
    ValueName = String(255, Chr(0))
    ValueNameLen = 255
    ReDim ValueValue(0 To 999)
    ValueValueS = vbNullString
    ' tell RegEnumValue to get the next registry value
    Ndx = Ndx + 1
    ' get the next printer
    Res = RegEnumValue(HKey, Ndx, ValueName, ValueNameLen, _
        0&, DataType, ValueValue(0), 1000)
    ' test for error
    If (Res <> 0) And (Res <> ERROR_MORE_DATA) Then
        Exit Do
    End If
Loop
' shrink Printers down to used size
ReDim Preserve Printers(1 To PNdx)
Res = RegCloseKey(HKey)
' Return the result array
GetPrinterFullNames = Printers
End Function

Sub Test()
    Dim Printers() As String
    Dim N As Long
    Dim S As String
    Printers = GetPrinterFullNames()
    For N = LBound(Printers) To UBound(Printers)
        S = S & Printers(N) & vbNewLine
    Next N
    MsgBox S, vbOKOnly, "Printers"
End Sub

Related Solutions

C# – How to create an Excel (.XLS and .XLSX) file in C# without installing Microsoft Office

You can use a library called ExcelLibrary. It's a free, open source library posted on Google Code:

ExcelLibrary

This looks to be a port of the PHP ExcelWriter that you mentioned above. It will not write to the new .xlsx format yet, but they are working on adding that functionality in.

It's very simple, small and easy to use. Plus it has a DataSetHelper that lets you use DataSets and DataTables to easily work with Excel data.

ExcelLibrary seems to still only work for the older Excel format (.xls files), but may be adding support in the future for newer 2007/2010 formats.

You can also use EPPlus, which works only for Excel 2007/2010 format files (.xlsx files). There's also NPOI which works with both.

There are a few known bugs with each library as noted in the comments. In all, EPPlus seems to be the best choice as time goes on. It seems to be more actively updated and documented as well.

Also, as noted by @АртёмЦарионов below, EPPlus has support for Pivot Tables and ExcelLibrary may have some support (Pivot table issue in ExcelLibrary)

Here are a couple links for quick reference:
ExcelLibrary - GNU Lesser GPL
EPPlus - GNU (LGPL) - No longer maintained
EPPlus 5 - Polyform Noncommercial - Starting May 2020
NPOI - Apache License

Here some example code for ExcelLibrary:

Here is an example taking data from a database and creating a workbook from it. Note that the ExcelLibrary code is the single line at the bottom:

//Create the data set and table
DataSet ds = new DataSet("New_DataSet");
DataTable dt = new DataTable("New_DataTable");

//Set the locale for each
ds.Locale = System.Threading.Thread.CurrentThread.CurrentCulture;
dt.Locale = System.Threading.Thread.CurrentThread.CurrentCulture;

//Open a DB connection (in this example with OleDB)
OleDbConnection con = new OleDbConnection(dbConnectionString);
con.Open();

//Create a query and fill the data table with the data from the DB
string sql = "SELECT Whatever FROM MyDBTable;";
OleDbCommand cmd = new OleDbCommand(sql, con);
OleDbDataAdapter adptr = new OleDbDataAdapter();

adptr.SelectCommand = cmd;
adptr.Fill(dt);
con.Close();

//Add the table to the data set
ds.Tables.Add(dt);

//Here's the easy part. Create the Excel worksheet from the data set
ExcelLibrary.DataSetHelper.CreateWorkbook("MyExcelFile.xls", ds);

Creating the Excel file is as easy as that. You can also manually create Excel files, but the above functionality is what really impressed me.

Excel – way to crack the password on an Excel VBA Project

You can try this direct VBA approach which doesn't require HEX editing. It will work for any files (*.xls, *.xlsm, *.xlam ...).

Tested and works on:

Excel 2007
Excel 2010
Excel 2013 - 32 bit version
Excel 2016 - 32 bit version

Looking for 64 bit version? See this answer

How it works

I will try my best to explain how it works - please excuse my English.

The VBE will call a system function to create the password dialog box.
If user enters the right password and click OK, this function returns 1. If user enters the wrong password or click Cancel, this function returns 0.
After the dialog box is closed, the VBE checks the returned value of the system function
if this value is 1, the VBE will "think" that the password is right, hence the locked VBA project will be opened.
The code below swaps the memory of the original function used to display the password dialog with a user defined function that will always return 1 when being called.

Using the code

Please backup your files first!

Open the file(s) that contain your locked VBA Projects

Create a new xlsm file and store this code in Module1

code credited to Siwtom (nick name), a Vietnamese developer

Option Explicit

Private Const PAGE_EXECUTE_READWRITE = &H40

Private Declare Sub MoveMemory Lib "kernel32" Alias "RtlMoveMemory" _
        (Destination As Long, Source As Long, ByVal Length As Long)

Private Declare Function VirtualProtect Lib "kernel32" (lpAddress As Long, _
        ByVal dwSize As Long, ByVal flNewProtect As Long, lpflOldProtect As Long) As Long

Private Declare Function GetModuleHandleA Lib "kernel32" (ByVal lpModuleName As String) As Long

Private Declare Function GetProcAddress Lib "kernel32" (ByVal hModule As Long, _
        ByVal lpProcName As String) As Long

Private Declare Function DialogBoxParam Lib "user32" Alias "DialogBoxParamA" (ByVal hInstance As Long, _
        ByVal pTemplateName As Long, ByVal hWndParent As Long, _
        ByVal lpDialogFunc As Long, ByVal dwInitParam As Long) As Integer

Dim HookBytes(0 To 5) As Byte
Dim OriginBytes(0 To 5) As Byte
Dim pFunc As Long
Dim Flag As Boolean

Private Function GetPtr(ByVal Value As Long) As Long
    GetPtr = Value
End Function

Public Sub RecoverBytes()
    If Flag Then MoveMemory ByVal pFunc, ByVal VarPtr(OriginBytes(0)), 6
End Sub

Public Function Hook() As Boolean
    Dim TmpBytes(0 To 5) As Byte
    Dim p As Long
    Dim OriginProtect As Long

    Hook = False

    pFunc = GetProcAddress(GetModuleHandleA("user32.dll"), "DialogBoxParamA")


    If VirtualProtect(ByVal pFunc, 6, PAGE_EXECUTE_READWRITE, OriginProtect) <> 0 Then

        MoveMemory ByVal VarPtr(TmpBytes(0)), ByVal pFunc, 6
        If TmpBytes(0) <> &H68 Then

            MoveMemory ByVal VarPtr(OriginBytes(0)), ByVal pFunc, 6

            p = GetPtr(AddressOf MyDialogBoxParam)

            HookBytes(0) = &H68
            MoveMemory ByVal VarPtr(HookBytes(1)), ByVal VarPtr(p), 4
            HookBytes(5) = &HC3

            MoveMemory ByVal pFunc, ByVal VarPtr(HookBytes(0)), 6
            Flag = True
            Hook = True
        End If
    End If
End Function

Private Function MyDialogBoxParam(ByVal hInstance As Long, _
        ByVal pTemplateName As Long, ByVal hWndParent As Long, _
        ByVal lpDialogFunc As Long, ByVal dwInitParam As Long) As Integer
    If pTemplateName = 4070 Then
        MyDialogBoxParam = 1
    Else
        RecoverBytes
        MyDialogBoxParam = DialogBoxParam(hInstance, pTemplateName, _
                           hWndParent, lpDialogFunc, dwInitParam)
        Hook
    End If
End Function

Paste this code under the above code in Module1 and run it

Sub unprotected()
    If Hook Then
        MsgBox "VBA Project is unprotected!", vbInformation, "*****"
    End If
End Sub

Come back to your VBA Projects and enjoy.