I work with a relay module that I normaly connect via USB. That all works perfectly. Now I would like to connect it via the network. All manufacturer's VB.NET code works in vba except for accessing this module over the network.
Public Declare PtrSafe Function DapiOpenModuleEx Lib "DELIB64" (ByVal moduleID As Long, ByVal nr As Long, ByRef exbuffer As DAPI_OPENMODULEEX_STRUCT, ByVal open_options As Long) As Long
' Definitions for DapiOpenEx
Public Type DAPI_OPENMODULEEX_STRUCT
address(255) As Byte
timeout As Long
portno As Long
encryption_type As Long
encryption_password(31) As Byte
End Type
'Open ETH-Module with parameter
Dim handle as Ulong
Dim MyModuleID As UInt32
MyModuleID = 42
Dim open_buffer As New DELib64.DAPI_OPENMODULEEX_STRUCT
open_buffer.address = System.String.Copy(192.168.1.1 As String) As String
open_buffer.portno = 0
handle = DELib.DapiOpenModuleEx(MyModuleID, 0, open_buffer)
I am getting an error "open_buffer.address = System.String.Copy(192.168.1.1 As String) As String "
Can someone help me with what i need to change here?
Dim handle as LongLong
Dim MyModuleID As Long
MyModuleID = 42
Dim open_buffer As Delib64.DAPI_OPENMODULEEX_STRUCT
open_buffer.address = system.String.Copy("192.168.1.1" AS String) As String
open_buffer.portno = 0
handle1 = DapiOpenModuleEx(MyModuleID, 0, open_buffer, 0)
According to your comment, the original line of code is
strcpy((char*) open_buffer.address, "192.168.1.10");
So you need to copy the ASCII (single-byte) string "192.168.1.10" into a VBA byte array. This is surprisingly hard, since the obvious approach of open_buffer.address = StrConv("192.168.1.10", vbFromUnicode) won't work (you can't assign to a fixed-size array that's part of a type).
One obvious solution would be to make a Windows API call to CopyMemory, but if we want a VBA-only solution, a simple loop should suffice:
Dim i As Long
Dim b() As Byte
b = StrConv("192.168.1.10", vbFromUnicode)
For i = 0 To UBound(b)
open_buffer.address(i) = b(i)
Next
open_buffer.address(UBound(b) + 1) = 0 ' C-strings need to be 0-terminated
(I do have the feeling that this should be easier, so I'll gladly upvote competing, simpler answers.)
Related
I want to store and compare hashed passwords in VBA.
I've read How do I properly implement Unicode passwords?, but I have no clue about where to start.
How do I normalize a unicode string in VBA?
Preferably, I'd do this without downloading the ICU the linked post refers to, because I'd like my project not to be dependent on external code.
Windows provides a built-in for normalizing strings, the NormalizeString function. However, it can be a bit tricky to use.
Here is an implementation, based on the C example in the docs provided above:
'Declare the function
Public Declare PtrSafe Function NormalizeString Lib "Normaliz.dll" (ByVal NormForm As Byte, ByVal lpSrcString As LongPtr, ByVal cwSrcLength As Long, ByVal lpDstString As LongPtr, ByVal cwDstLength As Long) As Long
'And a relevant error code
Const ERROR_INSUFFICIENT_BUFFER = 122
'And a helper enum
Public Enum NORM_FORM
NormalizationC = &H1
NormalizationD = &H2
NormalizationKC = &H5
NormalizationKD = &H6
End Enum
'Available normalization forms can be found under https://learn.microsoft.com/en-us/windows/win32/api/winnls/ne-winnls-norm_form
'KD normalization is preferred(https://stackoverflow.com/a/16173329/7296893) when hashing characters
'If you already have hashes stored, C normalization is least likely to break them
Public Function UnicodeNormalizeString(str As String, Optional norm_form As Byte = NormalizationKD) As String
If Len(str) = 0 Then 'Zero-length strings can't be normalized
UnicodeNormalizeString = str
Exit Function
End If
Dim outlenestimate As Long
'Get an initial length estimate for the string
outlenestimate = NormalizeString(norm_form, StrPtr(str), Len(str), 0, 0)
Dim i As Long
'Try 10 times
For i = 1 To 10
'Initialize buffer
UnicodeNormalizeString = String(outlenestimate, vbNullChar)
'Get either the normalized string, or a new length estimate
outlenestimate = NormalizeString(norm_form, StrPtr(str), Len(str), StrPtr(UnicodeNormalizeString), outlenestimate)
If outlenestimate > 0 Then 'We got the normalized string
'Truncate off the unused characters
UnicodeNormalizeString = Left(UnicodeNormalizeString, outlenestimate)
Exit Function
Else
If Err.LastDllError <> ERROR_INSUFFICIENT_BUFFER Then
Exit For 'An unexpected error occurred
End If
outlenestimate = outlenestimate * -1 'Use the new length estimate, try again
End If
Next
Err.Raise 5000, Description:="Failure to normalize unicode string"
End Function
Once you have declared the normalization function, always run your password through it before hashing:
If SomeHashFun(UnicodeNormalizeString(MyPassword)) = SomeHashedPassword Then
'We are in!
End If
As shown here: https://gregstoll.com/~gregstoll/floattohex/
I need to convert a 32 bit float to a little endian hex (click the swap endiness button before converting). I've managed to do this in python by converting to big endian then reordering, but I have no idea how to approach this issue in VB as I'm entirely new to the language. Using the Hex inbuilt function returns 19a, which i assume means its not correctly evaluating my input as a single.
I've found a recommended solution here but cant get it working:
https://www.tek-tips.com/faqs.cfm?fid=6404
Any suggestions would be great, thanks in advance.
There are a number of ways you could do this - the most obvious being the Copy Memory API. Some time ago, a pretty neat solution was published here: Extracting bits from a float in vba which avoided the need for the API
Basically, you'd just need a couple of short functions:
Option Explicit
Type SingleType
Value As Single
End Type
Type FourBytesType
Value(3) As Byte
End Type
Private Function SingleToBytes(f As Single) As Variant
Dim sngType As SingleType
Dim bytesType As FourBytesType
sngType.Value = f
LSet bytesType = sngType
SingleToBytes = bytesType.Value
End Function
Private Function BytesToHex(bytes As Variant) As String
Dim result As String
Dim i As Long
For i = LBound(bytes) To UBound(bytes)
result = result & IIf(bytes(i) < 16, "0", "") & Hex(bytes(i))
Next
BytesToHex = result
End Function
If you wanted to test Endianness and reverse the array, then something like the following, which kind of uses a Byte Order Mark, could be added. I haven't tested it on a big-endian processor but I think it'd work:
Private Function IsLittleEndianProcessor() As Boolean
Const BOM As Single = 1
Const MSB As Byte = 63
Dim bytes() As Byte
Dim n As Long
bytes = SingleToBytes(BOM)
n = UBound(bytes)
IsLittleEndianProcessor = (bytes(n) = MSB)
End Function
Private Function ChangeEndianness(bytes As Variant) As Variant
Dim result() As Byte
Dim n As Long, m As Long
ReDim result(UBound(bytes))
m = UBound(bytes)
For n = LBound(bytes) To UBound(bytes)
result(m) = bytes(n)
m = m - 1
Next
ChangeEndianness = result
End Function
I'm not actually sure how you want the hex string displayed but you could step backwards through the array to write the hex if needed. Sample test would be:
Public Sub TestMe()
Dim bytes As Variant
Dim output As String
bytes = SingleToBytes(3.1415)
If Not IsLittleEndianProcessor Then
bytes = ChangeEndianness(bytes)
End If
output = BytesToHex(bytes)
Debug.Print output
End Sub
I have a DLL with the following function and is being used in my application
WritetoBuffer(BYTE* pBuffer, DATA_TYPE Type);
This is the code being used in VB 6
Dim pBuffer() as byte
ReDim pBuffer(0 To (300 * 400 * 3 - 1))
Dim ppBuf As Long
ppBuf = VarPtr(pImageBuffer(0))
Dim Rtn As Integer
Rtn = WritetoBuffer(ppBuf, 1)
I am trying to write the equivalent code in VB.NET, but I am facing difficulties in it. Tried using the following function, but it's not working.
Public Function VarPtr(ByVal e As Object) As Intptr
Dim GC As GCHandle = GCHandle.Alloc(e, GCHandleType.Pinned)
Dim GC2 As Intptr = GC.AddrOfPinnedObject.ToInt32
GC.Free()
Return GC2
End Function
I haven't used Marshal Class or similar functions before and I am not sure about the right way to do it. Can someone please advice me on this?
As #Dai commented, .ToInt32 is incorrect here, and you can’t free the handle before you use it.
Dim pBuffer(300 * 400 * 3 - 1) As Byte
Dim pinned = GCHandle.Alloc(pBuffer, GCHandleType.Pinned)
Dim Rtn As Integer = WritetoBuffer(pinned.AddrOfPinnedObject(), 1)
pinned.Free()
Try this. You need GCHandle to stay alive while you make your call. Just returning the address of the pointer is not enough from what I understand. When you're done then free the handle.
Dim Handle As GCHandle = GCHandle.Alloc(pBuffer, GCHandleType.Pinned)
Dim ppbuf As IntPtr = Handle.AddrOfPinnedObject.ToInt32
Dim Rtn As Integer
Rtn = WritetoBuffer(ppbuf, 1)
Handle.Free()
In cases such as this you shouldn't need to get a pointer of your byte array. Due to the fact that since BYTE* pBuffer is used as an array, that is all you need it to be in VB.NET as well.
Thus you could declare your P/Invoke like this:
<DllImport("yourfile.dll")> _
Public Shared Function WritetoBuffer(ByVal pBuffer As Byte(), ByVal Type As Integer) As Integer
End Function
...and then use it like this:
Dim pBuffer() as byte
ReDim pBuffer(0 To (300 * 400 * 3 - 1))
Dim Rtn As Integer = WritetoBuffer(pBuffer, 1)
I have a old code in VB.Now I convert it into vb.net.There is a line in a code
Dim pCParameters As Integer
pCParameters = VarPtr(Parameters)
When I execute code the error occure that
Name 'VarPtr' is not declared.
VarPtr not supported in vb.net.So how I replace it.
This is not as straight forward because your variables in .NET are managed. To do exactly what you are asking you need to look at GCHandle.Alloc and pin the variable so it cannot be moved. Then you can get its memory address.
Something like this (from memory):
GCHandle handle = GCHandle.Alloc(pCParameters , Pinned )
IntPtr ptr = handle.AddressOfPinnedObject
Yes I found the answer.The new VarPtr function is
Public Function VarPtr(ByVal e As Object) As Integer
Dim GC As GCHandle = GCHandle.Alloc(e, GCHandleType.Pinned)
Dim GC2 As Integer = GC.AddrOfPinnedObject.ToInt32
GC.Free()
Return GC2
Using VB6. It's not hard to roll your own, but I wondered if was a prebuilt one out there?
Prompted by Bob's comment: Google found this wrapper for UrlEscape in a newsgroup post from Karl Peterson.
Private Declare Function UrlEscape Lib "Shlwapi.dll" Alias "UrlEscapeA" ( _
ByVal pszURL As String, ByVal pszEscaped As String, ByRef pcchEscaped As Long, _
ByVal dwFlags As Long) As Long
Private Const URL_DONT_ESCAPE_EXTRA_INFO As Long = &H2000000
Private Function EscapeURL(ByVal URL As String) As String
' Purpose: A thin wrapper for the URLEscape API function. '
Dim EscTxt As String
Dim nLen As Long
' Create a maximum sized buffer. '
nLen = Len(URL) * 3
EscTxt = Space$(nLen)
If UrlEscape(URL, EscTxt, nLen, URL_DONT_ESCAPE_EXTRA_INFO) = 0 Then
EscapeURL = Left$(EscTxt, nLen)
End If
End Function
Disclaimer: I haven't tried this code myself.
You should use CoInternetParseUrl(), with URL_ENCODE.
The sample from MSDN, modified for your purposes. Of course, you'll have to figure out how to call CoInternetParseUrl() from VB6, but you seem well on your way to that.
#include <wininet.h>
// ...
WCHAR encoded_url[INTERNET_MAX_URL_LENGTH];
DWORD encoded_url_len = ARRAYSIZE(encoded_url);
// Assumes |url| contains the value you want to encode.
HRESULT hr = CoInternetParseUrl(url, PARSE_CANONICALIZE, URL_ENCODE, encoded_url,
INTERNET_MAX_URL_LENGTH, & encoded_url_len, 0);
if (SUCCEEDED(hr)) {
// Do stuff...
}
You may want to use PARSE_ENCODE instead of PARSE_CANONICALIZE, depending on your needs.
Also, consider using google-url. May be difficult since it's C++ and not COM based.