MQL4 and DLL input export | Forex Factory

Options

Permalinks
Print Thread

Similar Threads

MQL, Matlab dll function > input as vector? 4 replies

Wininet.dll & user32.dll. Can we use it in Macintosh MT4/MT5? 0 replies

Multiple EAs using single DLL with DLL Windows - Using Delphi 9 replies

Convert dll back to mql4 3 replies

export tick/candle data from MT using DLL in EA 0 replies

MQL4 and DLL input export

  • #1
  • First Post: Edited Jun 18, 2018 4:16am Jun 17, 2018 6:50am | Edited Jun 18, 2018 4:16am
Hi all I have created a DLL that reads the data in a text file on the server and everything works correctly.
Now I want to split the URL in the DLL and pass part of the path as an input parameter in my mql code but it does not work.

my DLL is:

Inserted Code
extern "C" { __declspec(dllexport) int main(std::wstring Patc)
{
std::ofstream fout(L"c:\\test\\_test.htm");
std::wstring url = L"https://mysite.com/" + Patch;
 
HINTERNET hopen = InternetOpen(L"MyAppName", INTERNET_OPEN_TYPE_PRECONFIG, NULL, NULL, 0);
if (hopen)
{
DWORD flags = INTERNET_FLAG_DONT_CACHE; if (url.find(L"https://") == 0) flags |= INTERNET_FLAG_SECURE;
HINTERNET hinternet = InternetOpenUrl(hopen, url.c_str(), NULL, 0, flags, 0);
 
if (hinternet)
{
char buf[10000];
DWORD received = 0; int i;
while (InternetReadFile(hinternet, buf, sizeof(buf), &received))
{
if (!received) break; //fout.write(buf, received); int I = 0; int II = 5;
 
for (i = 0; i <= received; i++)
{
//-- my read code is good!!!
}
 
system("PAUSE");
}
InternetCloseHandle(hinternet);
}
InternetCloseHandle(hopen);
} return 0;
} }

My code Test Mql4 is:

Inserted Code
#import "Dll1.dll"
int main(string Patch);
#import
 
nt OnInit()
{
Print("Serial: ", main("Read.txt"));
return(INIT_SUCCEEDED);
}
  • #2
  • Jun 18, 2018 2:07am Jun 18, 2018 2:07am
Help me please?!?
  • #3
  • Jun 18, 2018 2:16am Jun 18, 2018 2:16am
Quoting Fly76
Help me please?!?
You have pass to DLL a char buffer with a fixed size and copy out string there. Later use mt4 string methods for convert it to string
Try don't lose pants never...
  • #4
  • Jun 18, 2018 2:22am Jun 18, 2018 2:22am
I did not understand sorry I could give me an example thanks!
  • #5
  • Edited 4:15am Jun 18, 2018 2:47am | Edited 4:15am
I tried this way but it does not work:

Inserted Code
__declspec(dllexport) int main(std::string A)
{
std::string s(A);
std::wstring ws= ws.assign(A.begin(), A.end());
 
std::wstring url2 = L"ReadCSV2.txt";
std::wstring url = L"https://mysite.com/";
url = url + L" "+ ws;
 
// my code....
}
  • #6
  • Jun 18, 2018 3:34am Jun 18, 2018 3:34am
MQL4:

#import "XXX"
uint main( string a, char & buffer[] );
#import

string a;
char * buffer[];

main(a, buffer );

C:
__declspec(dllexport) int main(std::string A, void * buffer )
Try don't lose pants never...
  • #7
  • Edited 3:50am Jun 18, 2018 3:37am | Edited 3:50am
Quoting Fly76
my DLL is:
Maybe you start with posting code the appropriate way? Use the editors "Source" function or put code into code tags. Who will bother reading your mess of letters? Second, there is an example code under "\MQL4\Scripts\Examples\DLL\DLLSample.cpp" of how to handle stuff.
Return To Disorder
  • #8
  • Jun 18, 2018 4:18am Jun 18, 2018 4:18am
Quoting rockit
{quote} Maybe you start with posting code the appropriate way? Use the editors "Source" function or put code into code tags. Who will bother reading your mess of letters? Second, there is an example code under "\MQL4\Scripts\Examples\DLL\DLLSample.cpp" of how to handle stuff.
sorry, you're right. I have corrected the formatting of the code
  • #9
  • Jun 18, 2018 4:26am Jun 18, 2018 4:26am
Quoting braintheboss
MQL4: #import "XXX" uint main( string a, char & buffer[] ); #import string a; char * buffer[]; main(a, buffer ); C: __declspec(dllexport) int main(std::string A, void * buffer )
sI receive the following violation error: Access violation read to 0xCCCCCCD0 in dll

Inserted Code
 __declspec(dllexport) int main(std::string A, void* buffer)
    {
      
         std::wstring ws= ws.assign(A.begin(), A.end());
         std::wstring url = L"https://mysite.com//";
         url = url + L" "+ ws;
 
   //my code...
}



MQL4 code:

Inserted Code
#import "Dll1.dll"
      
    uint main( string a, char & buffer[] );
    
#import
 
   string a;
   char buffer[];
   StringToCharArray("ReadCSV2.txt", buffer);
  • #10
  • Last Post: Jun 18, 2018 5:26am Jun 18, 2018 5:26am
Quoting Fly76
{quote} sI receive the following violation error: Access violation read to 0xCCCCCCD0 in dll __declspec(dllexport) int main(std::string A, void* buffer) { std::wstring ws= ws.assign(A.begin(), A.end()); std::wstring url = L"https://mysite.com//"; url = url + L" "+ ws; //my code... } MQL4 code: #import "Dll1.dll" uint main( string a, char & buffer[] ); #import string a; char buffer[]; StringToCharArray("ReadCSV2.txt", buffer);
Not idea but you shouldnt use std as parameter for strings. And you should pass string as variable. Never pass string as static constant. You should search examples in mql5 web.
Try don't lose pants never...
0 traders viewing now