Sample VBA code to open an Visual-Studio-2008-created VBA DLL


E

EagleOne

2003, 2007

Possible for someone to provide a few examples written in Excel VBA, which call a DLL (Excel
VBA-compiled in VS 2008 Visual Basic)?

In short, I have the myExcelVBA.DLL but cannot find VBA examples to "call" it properly.

How/Where do I declare the libraries necessary? (Assume I need to use all libraries/references used
to run the VBA from the VBA editor window.

TIA EagleOne
 
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J

Joel

Hre is code the call the FTP dll. You need to Alis which is the entry point
into the dll. the entry poit for basic is usally the function nmae (FTP)
with an "A" at the end.

Const MAX_PATH = 260


' Set Constants
Const FTP_TRANSFER_TYPE_ASCII = &H1
Const FTP_TRANSFER_TYPE_BINARY = &H2
Const INTERNET_DEFAULT_FTP_PORT = 21
Const INTERNET_SERVICE_FTP = 1
Const INTERNET_FLAG_PASSIVE = &H8000000
Const GENERIC_WRITE = &H40000000
Const BUFFER_SIZE = 100
Const PassiveConnection As Boolean = True


Type WIN32_FIND_DATA
dwFileAttributes As Long
ftCreationTime As Currency
ftLastAccessTime As Currency
ftLastWriteTime As Currency
nFileSizeHigh As Long
nFileSizeLow As Long
dwReserved0 As Long
dwReserved1 As Long
cFileName As String * MAX_PATH
cAlternate As String * 14
End Type

' Declare wininet.dll API Functions
Public Declare Function FtpSetCurrentDirectory Lib "wininet.dll" Alias
"FtpSetCurrentDirectoryA" _
(ByVal hFtpSession As Long, ByVal lpszDirectory As String) As Boolean

Public Declare Function FtpGetCurrentDirectory Lib "wininet.dll" Alias
"FtpGetCurrentDirectoryA" _
(ByVal hFtpSession As Long, ByVal lpszCurrentDirectory As String,
lpdwCurrentDirectory As Long) As Boolean

Public Declare Function InternetWriteFile Lib "wininet.dll" _
(ByVal hFile As Long, ByRef sBuffer As Byte, ByVal lNumBytesToWite As Long, _
dwNumberOfBytesWritten As Long) As Integer

Public Declare Function FtpOpenFile Lib "wininet.dll" Alias "FtpOpenFileA" _
(ByVal hFtpSession As Long, ByVal sBuff As String, ByVal Access As Long,
ByVal Flags As Long, ByVal Context As Long) As Long

Public Declare Function FtpPutFile Lib "wininet.dll" Alias "FtpPutFileA" _
(ByVal hFtpSession As Long, ByVal lpszLocalFile As String, _
ByVal lpszRemoteFile As String, _
ByVal dwFlags As Long, ByVal dwContext As Long) As Boolean

Public Declare Function FtpDeleteFile Lib "wininet.dll" _
Alias "FtpDeleteFileA" (ByVal hFtpSession As Long, _
ByVal lpszFileName As String) As Boolean
Public Declare Function InternetCloseHandle Lib "wininet.dll" _
(ByVal hInet As Long) As Long

Public Declare Function InternetOpen Lib "wininet.dll" Alias "InternetOpenA" _
(ByVal sAgent As String, ByVal lAccessType As Long, ByVal sProxyName As
String, _
ByVal sProxyBypass As String, ByVal lFlags As Long) As Long

Public Declare Function InternetConnect Lib "wininet.dll" Alias
"InternetConnectA" _
(ByVal hInternetSession As Long, ByVal sServerName As String, ByVal
nServerPort As Integer, _
ByVal sUsername As String, ByVal sPassword As String, ByVal lService As
Long, _
ByVal lFlags As Long, ByVal lContext As Long) As Long


Public Declare Function FtpGetFile Lib "wininet.dll" Alias "FtpGetFileA" _
(ByVal hFtpSession As Long, ByVal lpszRemoteFile As String, _
ByVal lpszNewFile As String, ByVal fFailIfExists As Boolean, ByVal
dwFlagsAndAttributes As Long, _
ByVal dwFlags As Long, ByVal dwContext As Long) As Boolean

Declare Function InternetGetLastResponseInfo Lib "wininet.dll" _
Alias "InternetGetLastResponseInfoA" _
(ByRef lpdwError As Long, _
ByVal lpszErrorBuffer As String, _
ByRef lpdwErrorBufferLength As Long) As Boolean

Public Declare Function FtpFindFirstFile Lib "wininet.dll" Alias
"FtpFindFirstFileA" _
(ByVal hInternetSession As Long, ByVal lpszSearchFile As String, _
ByRef lpFindFileData As WIN32_FIND_DATA, ByVal dwFlags As Long, _
ByVal dwContext As Long) As Long


Public Declare Function InternetFindNextFile Lib "wininet.dll" Alias
"InternetFindNextFileA" _
(ByVal hInternetSession As Long, ByRef lpvFindData As WIN32_FIND_DATA) As Long



Function FTPFile(ByVal HostName As String, _
ByVal UserName As String, _
ByVal Password As String, _
ByVal LocalFileName As String, _
ByVal RemoteFileName As String, _
ByVal sDir As String, _
ByVal sMode As String) As Boolean

On Error GoTo Err_Function

' Declare variables
Dim hConnection, hOpen, hFile As Long ' Used For Handles
Dim iSize As Long ' Size of file for upload
Dim Retval As Variant ' Used for progress meter
Dim iWritten As Long ' Used by InternetWriteFile to report bytes uploaded
Dim iLoop As Long ' Loop for uploading chuncks
Dim iFile As Integer ' Used for Local file handle
Dim FileData(BUFFER_SIZE - 1) As Byte ' buffer array of BUFFER_SIZE (100)
elements 0 to 99

' Open Internet Connecion
hOpen = InternetOpen("FTP", 1, "", vbNullString, 0)

' Connect to FTP
hConnection = InternetConnect(hOpen, HostName, INTERNET_DEFAULT_FTP_PORT,
UserName, Password, INTERNET_SERVICE_FTP, IIf(PassiveConnection,
INTERNET_FLAG_PASSIVE, 0), 0)

' Change Directory
Call FtpSetCurrentDirectory(hConnection, sDir)

' Open Remote File
hFile = FtpOpenFile(hConnection, RemoteFileName, GENERIC_WRITE, IIf(sMode =
"Binary", FTP_TRANSFER_TYPE_BINARY, FTP_TRANSFER_TYPE_ASCII), 0)

' Check for successfull file handle
If hFile = 0 Then
MsgBox "Internet - Failed!"
ShowError
FTPFile = False
GoTo Exit_Function
End If

' Set Upload Flag to True
FTPFile = True

' Get next file handle number
iFile = FreeFile

' Open local file
Open LocalFileName For Binary Access Read As iFile

' Set file size
iSize = LOF(iFile)

' Iinitialise progress meter
Retval = SysCmd(acSysCmdInitMeter, "Uploading File (" & RemoteFileName &
")", iSize / 1000)

' Loop file size
For iLoop = 1 To iSize \ BUFFER_SIZE

' Update progress meter
Retval = SysCmd(acSysCmdUpdateMeter, (BUFFER_SIZE * iLoop) / 1000)

'Get file data
Get iFile, , FileData

' Write chunk to FTP checking for success
If InternetWriteFile(hFile, FileData(0), BUFFER_SIZE, iWritten) = 0 Then
MsgBox "Upload - Failed!"
ShowError
FTPFile = False
GoTo Exit_Function
Else
' Check buffer was written
If iWritten <> BUFFER_SIZE Then
MsgBox "Upload - Failed!"
ShowError
FTPFile = False
GoTo Exit_Function
End If
End If

Next iLoop

' Handle remainder using MOD

' Update progress meter
Retval = SysCmd(acSysCmdUpdateMeter, iSize / 1000)

' Get file data
Get iFile, , FileData

' Write remainder to FTP checking for success
If InternetWriteFile(hFile, FileData(0), iSize Mod BUFFER_SIZE,
iWritten) = 0 Then
MsgBox "Upload - Failed!"
ShowError
FTPFile = False
GoTo Exit_Function
Else
' Check buffer was written
If iWritten <> iSize Mod BUFFER_SIZE Then
MsgBox "Upload - Failed!"
ShowError
FTPFile = False
GoTo Exit_Function
End If
End If

Exit_Function:

' remove progress meter
Retval = SysCmd(acSysCmdRemoveMeter)

'close remote file
Call InternetCloseHandle(hFile)

'close local file
Close iFile

' Close Internet Connection
Call InternetCloseHandle(hOpen)
Call InternetCloseHandle(hConnection)

Exit Function

Err_Function:
MsgBox "Error in FTPFile : " & Err.Description
GoTo Exit_Function

End Function

Function FTPGetDir(ByVal HostName As String, ByVal User As String, _
ByVal PassWd As String, ByVal Folder As String)

' Declare variables
Dim hConnection, hOpen As Long ' Used For Handles
Dim lpszCurrentDirectory As String
Dim lpdwCurrentDirectory As Long
Dim lpFindFileData As WIN32_FIND_DATA
Dim hfind As Long

lpszCurrentDirectory = String(1024, Chr(0))
lpdwCurrentDirectory = 1024

' Open Internet Connecion
hOpen = InternetOpen("FTP", 1, "", vbNullString, 0)

' Connect to FTP
hConnection = InternetConnect(hOpen, HostName, INTERNET_DEFAULT_FTP_PORT,
UserName, Password, INTERNET_SERVICE_FTP, IIf(PassiveConnection,
INTERNET_FLAG_PASSIVE, 0), 0)


Status = FtpGetCurrentDirectory(hConnection, _
lpszCurrentDirectory, lpdwCurrentDirectory)

hfind = FtpFindFirstFile(hConnection, lpszCurrentDirectory, _
lpFindFileData, IIf(PassiveConnection, _
INTERNET_FLAG_PASSIVE, 0), 0)

If hfind <> 0 Then
Range("A1") = lpFindFileData.cFileName
RowCount = 2
Do While lpFindFileData.cFileName <> ""

lpFindFileData.cFileName = String(MAX_PATH, 0)
Status = InternetFindNextFile(hfind, lpFindFileData)

If Status = 0 Then
Exit Do
Else
Range("A" & RowCount) = lpFindFileData.cFileName
RowCount = RowCount + 1
End If
Loop
End If
End Function
Sub ShowError()
Dim lErr As Long, sErr As String, lenBuf As Long
'get the required buffer size
InternetGetLastResponseInfo lErr, sErr, lenBuf
'create a buffer
sErr = String(lenBuf, 0)
'retrieve the last respons info
InternetGetLastResponseInfo lErr, sErr, lenBuf
'show the last response info
MsgBox "Last Server Response : " + sErr, vbOKOnly + vbCritical
End Sub

Sub FTP()

' Upload file
If FTPFile("ftp.domain.com", "myUserName", "myPassword", "Full path and
Filename of local file", "Target Filename without path", "Directory on FTP
server", "Upload Mode - Binary or ASCII") Then
MsgBox "Upload - Complete!"
End If
End Sub
Sub test_GetDirectory()
HostName = "ftp.microsoft.com"
User = "FTP"
PassWd = "(e-mail address removed)" 'enter email account
Folder = ""

Call FTPGetDir(HostName, _
User, _
PassWd, _
Folder)

End Sub
 
E

EagleOne

Interesting Joel.

So, if I have current VBA code that performs a series worksheet procedures called FixSheetsDll()
is the appropriate method: (BTW there are no variables or Constants passing into/out of the DLL.)


Private Declare Sub FixSheetsDll Lib "????" () 'What do I use as the Lib "????"
Sub CallMyDll()

Call FixSheetsDll()

End Sub


EagleOne
 
E

EagleOne

Would someone confirm the correct syntax if the Directory is "C:\MiscDllFiles"

Private Declare Sub FixSheetsDll Lib "C:\MiscDllFiles"
Sub CallMyDll()

Call FixSheetsDll()

End Sub
 
C

Chip Pearson

which call a DLL (Excel
VBA-compiled in VS 2008 Visual Basic)

What, exactly, does that mean? Did you create an Excel 2007
code-behind workbook or did you create Class Library DLL?

If you're referring to a DLL created as a class library, that assembly
must have been created as a COM visible assembly. That allows
COM-based applications (VB, VBA, VB6, etc) to call its functions. If
it isn't COM-visible, you won't be able to call its functions. You set
this property from the Assembly Information dialog on the Application
page of the My Project member of your project.

Once you have compiled the DLL as COM-visible, open the VBA editor, go
to the Tools menu, choose References and then Browse. Locate the
typelib file for the DLL (in the same folder as the DLL itself) and
load that typelib. Use the typelib file (assm_name.tlb not
assem_name.dll) rather than the DLL file.

Once you do that, you can call members of the one or more classes that
make up the DLL. For example, if your DLL is named MyExcelDLL.dll and
the class that contains the functions is called MyFunctionClass, you
can call a function, MyRealFunction with code like

Dim MF As MyExcelDLL.MyFunctionClass
Set MF = New MyExcelDLL.MyFunctionClass
Result = MF.MyRealFunction(1234)

With NET dlls, you don't use the Declare statement. That is used only
for Win32 DLLs, such as those created with __stdcall in VC++.

Cordially,
Chip Pearson
Microsoft Most Valuable Professional
Excel Product Group, 1998 - 2009
Pearson Software Consulting, LLC
www.cpearson.com
(email on web site)
 
E

EagleOne

Chip,

Obviously, this is virgin territory for me.

The purpose for the DLL was to compile the VBA code do as to secure same.

Therefore, I thought that, in VBA, I could call the DLL to process the compiled VBA code.

It appears that it is not that simple - therefore professionals like you exist.

That said, I am attempting to piece together a learning moment. I am not sure of:

"Use the typelib file (assm_name.tlb not assem_name.dll) rather than the DLL file." Does "assm"
mean Assembly?

i.e. If I "compiled" a VBA Sub "Test()" (w/s processing proceedure);
into a .DLL with VS 2008 Visual Basic Express,
how could I execute the VBA code in the DLL with VBA?

In short, for security I compiled Test() sub into a DLL.

How can I execute, using VBA, the contents of myExcelVBA.DLL?

Sorry, if I am not getting it. Hindsight is not available to me now.

Thanks EagleOne
 
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E

EagleOne

Forgot to mention that Test() does not pass variables either in/out.but just i.e., formats the
activesheet. Thus it is not a function per se.

Really I am trying to learn about VBA and DLLs. I got the VBA lightly down - I am just trying to
learn how to protect the code.

I would like to have the DLL work in 2003 and 2007 Excel VBA.

I believe that the main difference between a DLL and a Com Addin is Installing/Regestering the DLL
to be called in Office. I previously thought it was fine to have a DLL called vis VBA.

Chip, just shoot me.
 
E

EagleOne

Chip, I found the following but do not fully comprehend its impact.

Imports System
Imports System.Runtime.InteropServices

<Assembly: ComVisibleAttribute(False)>
Namespace InteroperabilityLibrary

<ComVisibleAttribute(False)> _
Public Class BaseClass

Sub SomeSub(valueOne As Integer)
End Sub

End Class

' This class violates the rule.
<ComVisibleAttribute(True)> _
Public Class DerivedClass
Inherits BaseClass

Sub AnotherSub(valueOne As Integer, valueTwo As Integer)
End Sub

End Class

End Namespace


I learn best if I have a "Template" that can be modified.

One of my challenges is that I never had assess to VB6.

Do you have a template that I could review so that I can get perspective to the task?


I am aware of the following on your site:
http://www.cpearson.com/excel/workbooktimebomb.aspx
http://www.cpearson.com/excel/creatingcomaddin.aspx
www.cpearson.com/Excel/creatingnetfunctionlib.aspx

Since I do not have any .NET nor VB6 (just VS 2008 Visual Basic Express), my mind can not make the
leap.

EagleOne
 
C

Chip Pearson

If you follow the example on the web page at
http://www.cpearson.com/excel/CreatingNETFunctionLib.aspx , you'll
have a class lib of functions that can be called from both a worksheet
cell, and, by setting a reference to the typelib.tlb file, in VBA. In
the code you posted, the line

<ComVisibleAttribute(False)> _

should be

<ClassInterface(ClassInterfaceType.AutoDual), ComVisible(True)> _


After all the functions in the class, use following, right before the
End Class marker. No changes are required for this code.

<ComRegisterFunctionAttribute()> _
Public Shared Sub RegisterFunction(ByVal type As Type)
Registry.ClassesRoot.CreateSubKey(GetSubkeyName(type))
End Sub

<ComUnregisterFunctionAttribute()> _
Public Shared Sub UnregisterFunction(ByVal type As Type)
Registry.ClassesRoot.DeleteSubKey(GetSubkeyName(type), False)
End Sub

Private Shared Function GetSubkeyName(ByVal type As Type) As String
Dim S As New System.Text.StringBuilder()
S.Append ("CLSID\{")
S.Append(type.GUID.ToString().ToUpper())
S.Append ("}\Programmable")
Return S.ToString()
End Function

You can't really "compile" VBA code into a DLL. You can, of course,
write the functionally equivalent code in one of the NET languages and
use that DLL, or you can have functions in VBA that do nothing beyond
calling functions in the NET dll.

There may be limitations on what can be done in the Express version of
VBNET. I'm don't they might be -- I use the Pro version of VS2008.

Cordially,
Chip Pearson
Microsoft Most Valuable Professional
Excel Product Group, 1998 - 2009
Pearson Software Consulting, LLC
www.cpearson.com
(email on web site)
 
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C

Chip Pearson

I meant to add that if you want a copy of the entire VB.NET project,
send me an email at (e-mail address removed) and I'll zip up a copy for you.

Cordially,
Chip Pearson
Microsoft Most Valuable Professional
Excel Product Group, 1998 - 2009
Pearson Software Consulting, LLC
www.cpearson.com
(email on web site)
 

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