Qt之调用C#的动态库的解决方法

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
 
namespace ClassLibrary1
{
    public class Class1
    {
        public Class1() { }
        public int myAdd(int a, int b)
        {
            int c = a + b + 5;
            return c;
        }
        public void mySub(int a, int b, ref int c)
        {
            c = a - b - 5;
        }
        public void mySetText(string text)
        {
            Console.WriteLine("ClassLibrary1的类名Class1下的mySetText: {0}", text);
        }
        public void myGetText(ref string text)
        {
            text = "ClassLibrary1的类名Class1下的myGetText";
        }
    }
}

#pragma once
 
using namespace System;
using namespace System::Reflection;
using namespace System::Runtime::InteropServices;
 
#using "./ClassLibrary1.dll"
 
using namespace ClassLibrary1;
 
extern "C" __declspec(dllexport) int MyAdd(int a, int b)
{
	ClassLibrary1::Class1 obj;
	return obj.myAdd(a, b);
}
extern "C" __declspec(dllexport) void MySub(int a, int b,int *c)
{
	ClassLibrary1::Class1 obj;
	return obj.mySub(a, b, *c);
}
 
extern "C" __declspec(dllexport) void MySetText(char* text)
{
	ClassLibrary1::Class1 obj;
	String^ str = gcnew String(text);
	obj.mySetText(str);
}
 
extern "C" __declspec(dllexport) void MyGetText(char** text)
{
	ClassLibrary1::Class1 obj;
	String^ str = gcnew String("");
	obj.myGetText(str);
	*text = (char*)(void*)Marshal::StringToHGlobalAnsi(str);
}

#include <QCoreApplication>
#include <windows.h>
#include <QDebug>
#include <QLibrary>
#include <QFile>
 
 
typedef int (*ADD)(int,int);
typedef void (*SUB)(int,int,int *);
typedef void (*SHOW)(QString);
int main(int argc, char *argv[])
{
    QLibrary mylib("ClassLibrary2.dll");  //声明dll文件
    if (mylib.load())  //判断加载是否成功
    {
        qDebug() << "DLL  loaded!";
        ADD add = (ADD)mylib.resolve("MyAdd"); //链接到add函数
        qDebug() << "add status: " << add;
        if (add){
            qDebug()<< "Link to add Function is OK!" << add(3,2) ;
        }
        SUB sub = (SUB)mylib.resolve("MySub");
        qDebug() << "sub status: " << sub;
        if (sub){
            int c = 10;
            sub(3,2,&c);
            qDebug()<< "Link to sub Function is OK!" << c;
        }
        SHOW show = (SHOW)mylib.resolve("MySetText");
        qDebug() << "show status: " << show;
        if (show){
            qDebug()<< "Link to show Function is OK!" ;
            const char *buf = "helloworld";
            show(buf);
        }
        qDebug()<< "DLL unload " << mylib.unload ();
    }
 
    else
    {
        qDebug()<< "DLL is not loaded!" ;
    }
    
    return 0;
}

extern "C" __declspec(dllexport) void MyGetText(char **p);
extern "C" __declspec(dllexport) void MySetText(char *p);
 
int main(int argc, char *argv[])
{
    MySetText(QString("helloworld").toUtf8().data());
    
    char* change_t=nullptr;
    MyGetText(&change_t);
    qDebug() << QString(change_t);
}