QLibrary解决方案返回false [英] QLibrary resolve returns false

问题描述

我试图动态地包含类文件，并通过加载.dll到QLibrary选择这样做。我现在的问题是，当我尝试调用resolve（） - 方法，它返回0。

I´m trying to include classfiles dynamically right now and chose to do so by loading the .dll into a QLibrary. The problem I´m having now is, that when I try to call the resolve()-method it returns 0.

编辑：
在此期间问题已经解决，我决定编辑代码，所以其他人可以看到它的工作原理：

In the meantime the problem has been solved and I decided to edit the code, so others can see how it works:

这是.dll的头文件：

#ifndef DIVFIXTURE_H
#define DIVFIXTURE_H

#include<QObject>
#include<QVariant>

class __declspec(dllexport) DivFixture : public QObject
{
    Q_OBJECT
public:
    Q_INVOKABLE DivFixture();
    Q_INVOKABLE void setNumerator(QVariant num);
    Q_INVOKABLE void setDenominator(QVariant denom);
    Q_INVOKABLE QVariant quotient();

private:
    double numerator, denominator;
};

#endif

这是dll的.cpp -file：

#include "testfixture.h"

DivFixture::DivFixture(){}

void DivFixture::setNumerator(QVariant num)
{
    numerator=num.toDouble();
}


void DivFixture::setDenominator(QVariant denom)
{
    denominator=denom.toDouble();
}


QVariant DivFixture::quotient()
{
    QVariant ret;
    ret=numerator/denominator;
    return ret;
}

//non-class function to return pointer to class
extern "C" __declspec(dllexport) DivFixture* create()
{
   return new DivFixture();
}

这是我如何加载我的类：

currentFixture.setFileName("C:\\somepath\\testFixture.dll");
if(currentFixture.load());
{
    typedef QObject* (*getCurrentFixture)();
    getCurrentFixture fixture=(getCurrentFixture)currentFixture.resolve("create");
    if (fixture)
    {
        Fixture=fixture();
    }
}

推荐答案

需要使用 __declspec（dllexport）

class __declspec(dllexport) DivFixture : public QObject
{

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