Question

我创建了一个虚拟项目（C ++）＆＃34;来创建DLL＆＃34;和对于编写的C_Wrapper： Myclass.h

#pragma once
//#include <QString>
class MyClass
{
public:
MyClass(double, double);
~MyClass();
double Add(double,double );
double Subst(double, double);
double Mult(double, double);
double Divid(double, double);
bool Vergleich(double,double);
long Avg_num(float *, long, float *);
unsigned int NumInteger(char * inputString);
//QString GibEinString(double, double);
private:
double m_a, m_b;
};

MyClass.cpp

#include "stdafx.h"
#include "MyClass.h"


MyClass::MyClass(double a,double b)
{
 this->m_a = a;
 this->m_b = b;
}

MyClass::~MyClass(){ }

double MyClass::Add(double a, double b) 
{
  return a+=b;
}
double MyClass::Mult(double a, double b)
{
  return a*=b;
}
double MyClass::Subst(double a, double b)
{
  return b-=a;
}
double MyClass::Divid(double a, double b)
{
  return (b / a);
}
bool MyClass::Vergleich(double a,double b)
{
   if(a>=b) return true;
   else return false;
}

long MyClass::Avg_num(float *a, long size, float *avg)
{
 float sum = 0;
 if(a != NULL)
 {
    for(int i=0;i < size; i++)
    sum = sum + a[i];
 }
  else
    return (1);
   *avg = sum / size;
    return (0);
   }
    unsigned int MyClass::NumInteger(char * inputString)
   {
     int lastDigit = 0;
      int numberOfNumbers = 0;
      int stringSize;

       stringSize = strlen(inputString);
     for(int i = 0; i < stringSize; i++)
      {
      if (!lastDigit && isdigit(inputString[i]))
        numberOfNumbers++;
        lastDigit = isdigit(inputString[i]);
       }
       return numberOfNumbers;

    }

C_Wrapper.h

#pragma once
#define DLLIMPORT __declspec (dllexport)
#ifdef __cplusplus
extern "C" { 
#endif

typedef struct Wrapper
{
  void *MYClass;
}Wrapper;

DLLIMPORT Wrapper createWrapper(double a, double b);
DLLIMPORT void destoryWrapper(Wrapper LV_ref);

DLLIMPORT double Add(Wrapper LV_ref, double a, double b);
DLLIMPORT double Subst(Wrapper LV_ref ,double a, double b);
DLLIMPORT double Mult(Wrapper LV_ref, double a, double b);
DLLIMPORT double Divid(Wrapper LV_ref, double a, double b);
DLLIMPORT bool Vergleich(Wrapper LV_ref, double a, double b);
DLLIMPORT long Avg_num(Wrapper LV_ref,float *a, long size, float * avg);
DLLIMPORT unsigned int NumInteger(Wrapper LV_ref, char * inputString);


#ifdef __cplusplus
}
 #endif

C_Wrapper.cpp

#include "stdafx.h"
#include "MyClass.h"
#include "C_DllWrapper.h"


DLLIMPORT Wrapper createWrapper(double a, double b)
{
  Wrapper wrapper = {static_cast<void*>(new MyClass(a,b))};
  return wrapper;
 }

 DLLIMPORT void destoryWrapper(Wrapper LV_ref)
 {
   MyClass *myClass = static_cast<MyClass*>(LV_ref.MYClass);
   delete myClass;
  }
  DLLIMPORT double Add(Wrapper LV_ref, double a, double b)
  {
   MyClass *myClass = static_cast<MyClass*>(LV_ref.MYClass);
   return myClass->Add(a, b);
   }

   DLLIMPORT double Mult(Wrapper LV_ref, double a, double b)
   {
     MyClass *myClass = static_cast<MyClass*>(LV_ref.MYClass);
     return myClass->Mult(a, b);
    }

    DLLIMPORT double Subst(Wrapper LV_ref, double a, double b)
    {
      MyClass *myClass = static_cast<MyClass*>(LV_ref.MYClass);
      return myClass->Subst(a, b);
     }

     DLLIMPORT double Divid(Wrapper LV_ref, double a, double b)
     {
       MyClass *myClass = static_cast<MyClass*>(LV_ref.MYClass);
       return myClass->Divid(a, b);
      }
      DLLIMPORT bool Vergleich(Wrapper LV_ref, double a, double b)
      {
        MyClass *myClass = static_cast<MyClass*>(LV_ref.MYClass);
        return myClass->Vergleich(a,b);
       }
       DLLIMPORT long Avg_num(Wrapper LV_ref,float *a, long size, float * avg)
       {
         MyClass *myClass = static_cast<MyClass*>(LV_ref.MYClass);
          return myClass->Avg_num(a,size,avg);

          }
         DLLIMPORT unsigned int NumInteger(Wrapper LV_ref, char * inputString)
          {
            MyClass *myClass = static_cast<MyClass*>(LV_ref.MYClass);
             return myClass->NumInteger(inputString);
            }

当我在Labview中导入DLL时，几乎可以做任何事情。我的问题主要是指一个函数：

DLLIMPORT Wrapper createWrapper(double a, double b)
{
 Wrapper wrapper = {static_cast<void*>(new MyClass(a,b)) };
 return wrapper;
}

如何在Labview中初始化？

谢谢

Answer 1

你不能用包含指针的结构来实现它，而是直接使用包装函数中的指针，并在LabVIEW中使用ptr类型

变成

typedef void* Wrapper;

DLLIMPORT double Mult(Wrapper LV_ref, double a, double b)
{
  MyClass *myClass = reinterpret_cast<MyClass*>(LV_ref);
  return myClass->Mult(a, b);
}

DLLIMPORT Wrapper createWrapper(double a, double b)
{
  Wrapper wrapper = reinterpret_cast<void*>(new MyClass(a,b));
  return wrapper;
}

Answer 2

标头文件

#pragma once
#ifdef __cplusplus
#endif

 extern "C"__declspec(dllexport) void* createWrapper(double a, double b);
 extern "C"__declspec(dllexport) void destoryWrapper(void *instance);
 extern "C"__declspec(dllexport) double Add(void *instance, double a, double b);

...

#ifdef __cplusplus
#endif

源文件：

#include "stdafx.h"
#include "MyClass.h"
#include "C_DllWrapper.h"


 extern "C"__declspec(dllexport) void* createWrapper(double a, double b)
 {
   return new MyClass(a, b);
 }

 extern "C"__declspec(dllexport) void destoryWrapper(void *instance)
 {
   MyClass *myClass = static_cast<MyClass*>(instance);
     delete myClass;
 }
 extern "C"__declspec(dllexport) double Add(void *instance, double a, double b)
 {
   MyClass *myClass = static_cast<MyClass*>(instance);
   return myClass->Add(a, b);
 }

.... 好的!!好的!!

Labview DLL导入

2 个答案: