All Questions
43 questions
2
votes
0
answers
86
views
Mac native function (ObjC / LibC) to call function with arguments
I maintain a 'modern' VBA library on github stdVBA. The library provides a high level wrapper on top of many low level functions in Windows OS. Mac compatibility is desired and the main obstruction is ...
- 2,784
0
votes
1
answer
134
views
Return a Variant from a c dll to Excel VBA on macos
In Paulo Bueno's project https://github.com/buenop/MinXL he returns a Variant from a C++ dll, e.g.
Declare PtrSafe Function IncrementArrayBy _
Lib "/Library/Application Support/Microsoft/...
- 724
0
votes
0
answers
111
views
Best way to return a dynamically sized array from C dll to VBA
I have read a few posts on this now but none quite answer what I am after.
I am writing a C dll (not C++) to read a specific type of data file, and return the data to vba for display in excel. For ...
- 487
0
votes
0
answers
184
views
Pass String from VBA to C DLL to Modify as a Parameter and Return
My journey learning about C DLL's and their interaction with VBA continues. The setup is I want to pass a string to the C DLL as a parameter, have the DLL modify the string, and return a return code ...
- 11
2
votes
0
answers
400
views
Unable to run C coded DLL in Excel VBA
I have a Windows 10 64-bits, Office 2013 32-bits and using MinGW64.
I followed instructions from https://www.transmissionzero.co.uk/computing/building-dlls-with-mingw/
I checked other answers ...
- 21
1
vote
2
answers
435
views
Close a txt file opened by another process in Windows programmatically
I am looking to force close a txt file that is opened by another process. Looking for suggestions, ideas on how this can be accomplished, and the caveats involved.
Python solution would be great, ...
- 974
0
votes
1
answer
51
views
I would like to replicate this nested for loop I have in c in an excel vba
Note:I'm aware that this explanation is confusing but when you look at the code I posted it will make a lot more sense. Feel free to suggest any edits.
I'm trying to recreate a a nested for loop I ...
- 7
2
votes
0
answers
59
views
Prevent Excel file from remember old DLL data. DLL Hell?
I've made simlpe C DLL:
void msgbox(long n)
{
char tmp[255];
sprintf(tmp, "%ld", n);
MessageBoxA(0, tmp, "DLL Message", MB_OK | MB_ICONINFORMATION);
}
void DLL_EXPORT ...
- 412
1
vote
1
answer
131
views
Malloc error in excel called .exe library
I'm using office 365 in 64 bit, with Windows 10 OS.
I compile my .exe file with Visual Studio 2017 Community.
Each time I met malloc() function, it report a violation of memory access.
It is nearly ...
- 1,003
0
votes
2
answers
327
views
How to call a C DLL from a VBA application and return an array?
I'm developing a a VBA application which writes and reads a serial port through a C DLL. In the code below I have managed to return a value into the VBA code in the form of a string.
What I want to ...
- 3
4
votes
2
answers
9k
views
Use DLL in excel-vba
i would love to know how to declare and use a dll in vba. I have a code written in C and i would like to use some data from an excel sheet to test my c-code. How is it possible?
Many thanks in advance
2
votes
1
answer
808
views
Error accessing 64bit DLL function
I have created a 64bit DLL file using Microsoft Visual Studio 2015.
Visual C --> Win32 Project.
The code for squareMain.c is as follows :
long _stdcall square(long a)
{
return a*a;
}
The code ...
- 287
2
votes
2
answers
954
views
How can I receive "char *d" from DLL in VBA(Excel Visual Basic)?
Now I'm trying to get a char string as the below c function.
This is a C function of DLL,
char _stdcall *fmt_hex(long long num, int nbits, char *d)
{
sprintf(d, "0x%0*llX", (nbits - 1) / ...
- 181
0
votes
0
answers
57
views
editing table using vba
I'm trying to edit the following table (the left one in the picture): I have columns of x, y, test name, pass/fail (0 if pass and 1 if fail), and "firstFAIL" column.
For each pair of x and y I have to ...
- 21
2
votes
1
answer
981
views
Send a BSTR string written in a C DLL to Excel
I am trying to send a BSTR string written in a C DLL to Excel.
Problem:
Excel VBA receives the BSTR from the C DLL. I can see the BSTR in the VBA Intermediate window and debug window.
If I try to ...
- 495
0
votes
1
answer
290
views
How do I build a Type to pass to a DLL function that takes a pointer to a struct with an array inside?
I have a C DLL that defines a struct and a function that takes a pointer to it:
header:
typedef struct {
double arr[10];
double anotherParam;
double result;
} CStruct_t;
int __stdcall ...
- 8,615
1
vote
0
answers
110
views
Unexpected Results When Returing BSTR from DLL to Microsoft Excel VBA Application
I am writing a VBA extension in C, from what I have read VBA uses BSTR, which is just a WCHAR* with a length prefix. I have a function:
__declspec(dllexport) VB_STRING _stdcall getStr()
{
return ...
- 876
2
votes
2
answers
973
views
Excel VBA script crashes when calling a DDL function written in C, which returns a string BSTR
I'm using Code::Blocks to write a DLL in C which I intend to use in a Winbatch script but for the moment I'm testing it using Excel VBA.
The moment the VBA script runs the DLL getVersion() function ...
- 23
1
vote
1
answer
406
views
How to print a variable length string of a single character
I have a need to print a variable number of a given character in conjunction with my formatted output. I was looking for something similar or equivalent to the VBA function String(num, char), but ...
- 83
1
vote
2
answers
241
views
Excel VBA not working well with C dll for decimals - works fine with integers
I have a problem that really stumps me. Ultimately, I think that the problem could very well be down to my lack of knowledge about C programming for Windows or how to properly work between C and VBA.
...
- 39
1
vote
2
answers
4k
views
C++ to VBA (Excel)
So, basically, in Excel, I have 4 columns of data (all with strings) that I want to process, and want to have the results in another column, like this (nevermind the square brackets, they just ...
- 23
0
votes
3
answers
56
views
checking and setting variable, efficiently
I am new to programming and have a simple question: is there a "better" or more efficient way of doing this...
if (x != 0) {
y = x;
}
or
if (getMethod() != null) {
value = getMethod();
}
I'm ...
- 35
4
votes
1
answer
214
views
How to Pass value as dynamic array from vb to c
I have below declaration:
Type routineStruct
man As String * 3
number As String * 5
End Type
Type vbToC
sch As String * 4
routine(0 To 10000) As routineStruct
End Type
vbfun As vbToC
Now ...
0
votes
1
answer
498
views
LPARAM as pointer to VBA variable
I'm building a very simple win32 console application which is coded in C and compiled using Visual Studio 2010/2013. It will have a message queue running in a separate thread from the main one. The ...
- 371
2
votes
1
answer
871
views
copy multiple pdf files data to excel in different worksheets
I have created a vba script to copy all data from multiple pdf files and paste in a excel in different tabs with the same name of the pdf files.
Problem is its copying data from pdf files and pasting ...
- 247
1
vote
1
answer
115
views
How to print a C BSTR in Excel 16 for Mac with VBA?
I have a C function which returns a BSTR like "Hello world" and in Excel 11 I can call this function to print the string with the msgbox vba function.
With Excel 16, I only have an returned empty ...
- 87
2
votes
1
answer
1k
views
Implementing Rosseta Code FFT into VBA Excel
I attempted to implement the FFT Rosetta Code into VBA excel. I was unable to reconstruct the same output data exactly as written in the Rosetta Code. At first I thought it was type conversion ...
- 809
-6
votes
2
answers
330
views
Translate this simple C code to VBA
I am looking to print an output that constitutes a string and a float.
For example, I calculated the density of a box using D = Mass/Volume. I would now like to generate an output saying "The density ...
- 11
4
votes
1
answer
1k
views
DLL compiled from C source code. Not able to use in excel VBA. File not found error
I have written a function in C (for some bitwise operations on 64-bit) and I want to use that function in my excel vba macro.
I used steps described here to create a DLL file using cygwin (64-bit).
...
- 43
0
votes
1
answer
219
views
VBA and dlls in C: Strategy for more responsive and controllable Excel performance?
I have an Excel workbook that another (3rd party. Not under my control) application pushes data onto. I have written various VBA functions that are triggered via an Worksheet.Change event when certain ...
- 23
0
votes
1
answer
330
views
Avoid basic rand() bias in Monte Carlo simulation?
I am rewriting a monte carlo simulation in C from Objective C to use in a dll from VBA/Excel. The "engine" in the calculation is the creation of a random number between 0 and 10001 that is compared to ...
- 23
1
vote
1
answer
64
views
Problems comparing integers to hardcoded values in a dll called from VBA
I am about to transfer a project I have written in Applescript and Objective C to Excel/VBA/dll. I have started with the Objective C functions that I want to place in a dll and call via VBA.
First of ...
- 23
2
votes
0
answers
99
views
C dll call from VBA : strange behavior
I write a C dll compiled in 64 bits with the following function:
in the .h :
_FF_EXPORT double __stdcall add(double a, double b);
in the .c :
double __stdcall add(double a, double b)
{
return a+...
- 1,762
0
votes
1
answer
48
views
MS Access: Search through Table for the same part of the String
I am trying to loop through Column Values inside my Table.
I have a register form, which provides the user with UNIQUE ID, based uppon his information.
For example:
Country = Austria
Each user that ...
- 1,059
1
vote
1
answer
576
views
Porting a VBA Type / C struct to a Python ctypes.Structure: array of strings with fixed length
I am trying to port a piece of VBA code to Python. This effort includes calling a function in a Windows DLL. The function requires a pointer to a C struct (in VBA, they are called "Type") as a ...
- 3,691
1
vote
2
answers
175
views
Logic for grouping similar parameters
I am trying to figure out the best logic for grouping parameters within a certain tolerance. It's easier to explain with an example...
Task1: parameter1=140
Task2: parameter1=137
Task3: parameter1=...
- 115
2
votes
1
answer
310
views
C function in Excel 64 bit does not work as a worksheet function but works well in VBA
I am writing a 64 bit Dll in C which is then used in Excel 64 bit, and I am following a sample project from https://sites.google.com/site/jrlhost/links/excelcdll.
The example is simple. We write a ...
- 23
1
vote
1
answer
970
views
calling a dll function from MS access
hi I'm trying to call this function in ms access vba. It just throws up bad calling convention. I tried to recompile access but zilch. I have called dll functions before so perhaps I’ve missed ...
- 11
1
vote
0
answers
734
views
Getting IDispatch interface pointer for running application (e.g. Excel)
Suppose I can write (in pseudocode)
ptr = CreateObject("Excel.Application")
And doing that creates an instance of excel.exe and gives me the dispatch pointer for the Excel.Application interface.
Is ...
- 234k
1
vote
1
answer
215
views
Declare a variable Registry in VBA?
New to VBA here. We can decare a variable as "Register" in C/C++ for very-very frequently accessed variable, ex- Loop iterator variables.
Does similar system exist in Visual Basic for Application. I ...
- 11
1
vote
1
answer
578
views
Call an executable of OCaml or C from VBA code
Under Ubuntu I have coded a very simple ml.ml in OCaml:
let () = print_string "hello world, in OCaml\n"
And a simple c.cin C:
#include <stdio.h>
main() {
printf("hello world, in C\n");
...
- 5,462
1
vote
2
answers
439
views
Handling BSTRs on MacOSX in C
I've written some code in C for converting strings passed from VBA, when the C code is called from VBA from a MacOSX dylib. I got some good hints here, and since I only care about ASCII strings I've ...
- 146
1
vote
3
answers
1k
views
Return string to VBA in MacOSX
I'm currently writing a C dynamic library in MacOSX, the functions are then used in Excel (2011) using the VBA, e.g.:
Declare Function TestF Lib "path_to_lib:mylib.dylib" Alias "test" (ByRef res As ...
- 146