c++ - 如何通过引用将参数从MQL4传递给C++ DLL

我试图在MQL4中编写一个简单的程序，该程序通过引用将变量传递给C++ DLL函数，并在MQL4中打印更新的变量值。下面给出的是我的代码。

DLL功能:

void Test(int* X)
{
    *X = 6;
}

MQL4代码

#import "Test.dll"
void Test(int&);
#import

void OnStart()
{
  int A;
  Test(A);
  Alert(A);
}

但是我没有从C++函数中获取变量A的任何值(value)。有人可以帮助我在这里做错什么吗？

提前致谢

最佳答案

让我们从DLL端开始:

int TestMoreApproachesAtONCE( int *X,
                              int *Y,
                              int  Z
                              )
{
    *X = 6;                   // 6 assigned to a 4B-memory chunk ref'd by *X
     Y = 6;                   // 6 assigned to a variable  Y
     return( Z );             // Z returned as a value passed from Caller
}

MQL4要求DLL具有:



现在演示MQL4端:

#import    "Test.dll" // -----------------------------------------------

                         void Test( int& );

                         int  TestMoreApproachesAtONCE( int &X,
                                                        int &Y,
                                                        int  Z
                                                        );
#import // "Test.dll" // -----------------------------------------------

void OnStart()
{
     int A = EMPTY,
         B = EMPTY,
         C = EMPTY;
  // ---------------------------------------------------<PRE>
     Print( " TEST:: inital values are: A = ", A,
                                      " B = ", B,
                                      " C = ", C
                                      );
  // ---------------------------------------------------<TEST>

     C = TestMoreApproachesAtONCE( A, B, 6 );

  // ---------------------------------------------------<POST>
     Print( " TEST::  final values are: A = ", A,
                                      " B = ", B,
                                      " C = ", C
                                      );

}

Anyway, enjoy the Wild Worlds of MQL4 -- Also may enjoy to click and read other posts on issues in MQL4/DLL integration and/or signalling/messaging in MQL4 domains. Feel free to ask more

最后，MQL4文档指出:

关于c++ - 如何通过引用将参数从MQL4传递给C++ DLL，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/39520941/