从其他dll调用dll函数 [英] Calling dll function from other dll

问题描述

我不是程序员，但可以做一点点编程.
我正在为特定内容编写该程序.我有一个来自fxcm(forex broker)的dll文件，可以对其进行API调用，并且在这里可以正常工作的代码是:

I am not a programmer but can do little bit of programming.
I am writing this program for specific thing. I have a dll file from fxcm(forex broker) to which i can do API calls and its working fine here is the code:

#include<iostream>
#import "C:\\Program Files\\Candleworks\\FXOrder2Go\\fxcore.dll"

int main(int argc, char *argv[])
{
    FXCore::ICoreAutPtr core;
    FXCore::ITradeDeskAutPtr tradeDesk;

    CoInitialize(NULL);
    HRESULT hr = core.CreateInstance(__uuidof(FXCore::CoreAut));
    if (FAILED(hr))
    {
        printf("Core creation failed %08x", hr);
        return -1;
    }

    try
    {
        tradeDesk = core->CreateTradeDesk(L"trader");
    }
    catch (_com_error e)
    {
        printf("Trade desk creation failed: %S", (const wchar_t *)e.Description());
        return -1;
    }

    try
    {
        tradeDesk->Login(L"xxxx", L"xxx", L"http://www.fxcorporate.com", L"Demo");
    }
    catch (_com_error e)
    {        
        tradeDesk->Logout();
        printf("Can't login : %S", (const wchar_t *)e.Description());
        return -1;
    }
    
    _bstr_t acct_id;
    int base_unit_size;
    try
    {
        FXCore::ITableAutPtr table = tradeDesk->FindMainTable(L"Accounts");
        acct_id = table->CellValue(1, L"AccountID");
        base_unit_size = table->CellValue(1, L"BaseUnitSize");
        printf("%S %i\n", (const wchar_t *)acct_id, base_unit_size);
		system("PAUSE");
    }
    catch (_com_error e)
    {        
        tradeDesk->Logout();
        printf("Can't get account info : %S", (const wchar_t *)e.Description());
        return -1;
    }

    _variant_t order_id, dealer_i;
    try
    {
        tradeDesk->OpenTrade(acct_id, L"USD/JPY", VARIANT_TRUE, base_unit_size, 0, L"", 0, 0, 0, 0, &order_id, &dealer_i);
    }
    catch (_com_error e)
    {
        tradeDesk->Logout();
        printf("Can't open a trade : %S", (const wchar_t *)e.Description());
		system("PAUSE");
        return -1;
    }

    printf("order id %S", (const wchar_t *)(_bstr_t)order_id);
	system("PAUSE");

    tradeDesk->Logout();
}


//Now, i have created other unmanaged dll which i use with MT4(forex application ) and it is working fine too

#include <stdafx.h>

//----
#define MT4_EXPFUNC __declspec(dllexport)
//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+

BOOL APIENTRY DllMain(HANDLE hModule,DWORD ul_reason_for_call,LPVOID lpReserved)
  {
//----
     switch(ul_reason_for_call)
     {
      case DLL_PROCESS_ATTACH:
      case DLL_THREAD_ATTACH:
      case DLL_THREAD_DETACH:
      case DLL_PROCESS_DETACH:
         break;
     }
//----
   return(TRUE);
  }
//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
 
  MT4_EXPFUNC char* __stdcall LogIn(char *id, char *password)
  {
	 
	  return("logedin");
  }

//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
MT4_EXPFUNC int __stdcall GetIntValue(const int ipar)
{
   
   return(ipar);
}
//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
MT4_EXPFUNC char* __stdcall GetStringValue(char *spar)
{
   
   return(spar);
}
//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+

MT4_EXPFUNC char* __stdcall OpenOrder(char *type, char *inst, double lot)
{
  
   return("open order");
}
</stdafx.h></iostream>

我也有.def和.h文件，但我没有附加它们.

我的问题:

我想调用从第一个程序到第二个程序的所有函数，而我不再想要第一个程序，则意味着
在我的第一个程序中，我导入了.dll文件，我想在第二个程序中导入该文件并调用那些函数.我该怎么办?

谢谢

I have .def and .h file as well but i didn''t attach them.

My Issue:

I want to call all the function from first program to second program and i dont want first program anymore then means
in my first program i imported .dll file, i want to import that in second program and call those function. How do i do that?

Thank You

推荐答案

这样做没有太大区别.
唯一的区别是第一个程序只有一个入口点(main函数).
但是在第二个程序中，有多个入口点(例如LogIn，GetIntValue等).

因此，理想情况下，您将在DllMain中执行CoInitialize和CreateInstance并从其他导出的函数中调用所需的函数.
或者，您可以像在DllMain中的第一个程序中一样调用所有方法. 这完全取决于程序的工作方式.

There is not much of a difference to do this.
The only difference here is that the first program has a single entry point (main function).
But in the second program there are multiple entry points (like LogIn, GetIntValue etc.)

So ideally you will do CoInitialize and CreateInstance in DllMain and call the required functions from the other exported functions.
Or you can call all the methods just like in the first program in DllMain.
This purely depends on how the program must work.

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