Passing multi parameter array to a C++ DLL

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Cannot find 'ProcessFFTW' in 'DLLTest1.dll'
unresolved import function call

#import "DLLTest1.dll"
void ProcessFFTW(double &inputArray[], double &outputArray[][2], int, double);
#import
 
void OnStart()
{
    double threshold = 5.0;
    double inputArray[]={1.5, 2.6, 3.7, 4.8, 5.9};
 
    int count = ArraySize(inputArray);
    double outputArray[][2];
 
    ProcessFFTW(inputArray, outputArray, count, threshold);
 
    Alert(outputArray[2][2]);
}

#include "stdafx.h"
 
#define MT4_EXPFUNC __declspec(dllexport)
 
MT4_EXPFUNC void _stdcall ProcessFFTW(double *input[], double *output[][2], int barCount, double threshold)
{
    output[2][2] = input[2];
}

Quoting skinner36

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Hi, Firstly, my apologies. I meant the subject to say, "Passing a multi dimensional array to a C++ DLL" I want to offload some time consuming tasks to a C++ DLL and I am having a bit of trouble with one aspect of it. I want to pass a two dimension array to the DLL but every time I run my MQL4 script I get the following error {quote} If I use single dimension arrays then there is no problem and it all works as expected. My issue only occurs if I try to pass a 2 dimensional array to the DLL. Can I only pass single dimension arrays from MQL? The MQL...

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Quoting skinner36

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...I have implemented 2 single dimension arrays to do the job...

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Quoting braintheboss

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{quote} You should avoid use mutiarrays with mql. It have many limitations. Make local methods calls are a pain too...

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Quoting emmzett

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{quote} There are no limitations handling multidimensional arrays in MQL or C++. I use it all the time, so for sure your actual issue is somewhere else in your code. Start with the examples distributed by MetaQuotes, they pass multidimensional arrays to DLLs, too. Add more debugging to your code (use the excellent DebugView from Sysinternals) to find your real issue. {quote} Don't listen to bad advise. Obviously the poster lacks experience with the matter.

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Quoting braintheboss

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...You can give your opinion to OP about topic...

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Quoting emmzett

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{quote} Maybe you re-read my post, I already did that. This thread is not the place to discuss your personal sensitivities. What counts is what you posted, not why. So if you don't like my reply just use the "Ignore" button, that's what it is for. This will be my only reply to you here. Get over it.

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Quoting emmzett

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{quote} There are no limitations handling multidimensional arrays in MQL or C++. I use it all the time, so for sure your actual issue is somewhere else in your code. Start with the examples distributed by MetaQuotes, they pass multidimensional arrays to DLLs, too. Add more debugging to your code (use the excellent DebugView from Sysinternals) to find your real issue. {quote} Don't listen to bad advise. Obviously the poster lacks experience with the matter.

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Quoting skinner36

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{quote} Hi Emmzett, i have looked at the examples in the Script\Examples\DLL directory and I can only find examples of single dimension arrays being past. You say that you do it all the time, would you mind sharing a small snippet of code showing how please? Thanks, John

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//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
MT4_EXPFUNC double __stdcall GetRatesItemValue(const RateInfo* rates,const int rates_total,const int shift,const int nrate)
  {
//---
   if(rates==NULL)
     {
      printf("GetRatesItemValue: NULL array\n");
      return(0.0);
     }
//---
   if(rates_total<0)
     {
      printf("GetRatesItemValue: wrong rates_total number (%d)\n", rates_total);
      return(0.0);
     }
//---
   if(shift<0 || shift>=rates_total)
     {
      printf("GetRatesItemValue: wrong shift number (%d)\n", shift);
      return(0.0);
     }
//---
   if(nrate<0 || nrate>5)
     {
      printf("GetRatesItemValue: wrong rate index (%d)\n", nrate);
      return(0.0);
     }
//---
   int nitem=rates_total-1-shift;
   switch(nrate)
     {
      case 0: return double(rates[nitem].ctm);
      case 1: return rates[nitem].open;
      case 2: return rates[nitem].low;
      case 3: return rates[nitem].high;
      case 4: return rates[nitem].close;
      case 5: return double(rates[nitem].vol_tick);
     }
//---
   return(0.0);
  }

#import "ArrayTest.dll"
    void ArrayTestingFunction(double &testArray[][]);
#import
  
int OnInit()
{
    double testArray[10][6];
        
    // Give an element a test value
    testArray[1][1] = 5;
 
    // Call the DLL with the array
    ArrayTestingFunction(testArray);
 
    // Check the array element to see if we can see how it was modified in the DLL
    Alert(testArray[1][1]);
 
    return(INIT_SUCCEEDED);
}

#include "stdafx.h"
#define MT4_EXPFUNC __declspec(dllexport)
 
MT4_EXPFUNC void _stdcall ArrayTestingFunction(double* testArray)
{
    double value = testArray[1][1];
 
     // Change the value in  the array and check for the new value in the calling EA
     testArray[1][1] = value * 2;
}

Quoting skinner36

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...I am still well and truly stuck...

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MT4_EXPFUNC void _stdcall ArrayTestingFunction(double testArray[][10]) {
   testArray[1][1] = testArray[1][1] * 2;
}

#property strict
 
#import "ArrayTest.dll"
    void ArrayTestingFunction(double &testArray[][10]);
#import
 
  
int OnInit()
{
    double testArray[][10];
        
    ArrayResize(testArray,10);
 
    // Give an element a test value
    testArray[1][1] = 5;
 
    // Call the DLL with the array
    ArrayTestingFunction(testArray);
 
    // Check the array element to see if we can see how it was modified in the DLL
    Alert(testArray[1][1]);
 
    return(INIT_SUCCEEDED);
}

Quoting skinner36

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...when I run the EA I get "Cannot find 'ArrayTestingFunction' in 'ArrayTest.dll'" and then "unresolved import function call" errors....

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#define MT4_EXPFUNC __declspec(dllexport)
 
MT4_EXPFUNC int _stdcall MyFunctionName() {
    return(0);
}

#define MYDLL_EXPORT comment(linker, "/EXPORT:"__FUNCTION__"="__FUNCDNAME__)
 
int WINAPI MyFunctionName() {
    return(0);
    #pragma MYDLL_EXPORT
}

HKEY_CURRENT_USER\Software\Heaventools

MT4_EXPFUNC void _stdcall ArrayTestingFunction(double testArray[][10])

#import "ArrayTest.dll"
    void ArrayTestingFunction(double &testArray[][10]);
#import