C#•3mo ago

✅ Using a C# DLL in C++

im actually trying to call a C# dll from c++ with DllExport, the c++ code return no error but dont execute the functions, here is the source : C# :

using System.Runtime.InteropServices;
using System;


namespace InternalTest
{
    public class Class1
    {
        
        [DllImport("user32.dll")]
        public static extern int MessageBox(int hWnd, string text, string caption, uint type);


        [DllExport(CallingConvention = CallingConvention.StdCall)]
        public static void DllEntryPoint()
        {
            Console.WriteLine("This is a message from C#");
            MessageBox(0, "C# is good", "hello world", 0);
        }
    }
}

using System.Runtime.InteropServices;
using System;


namespace InternalTest
{
    public class Class1
    {
        
        [DllImport("user32.dll")]
        public static extern int MessageBox(int hWnd, string text, string caption, uint type);


        [DllExport(CallingConvention = CallingConvention.StdCall)]
        public static void DllEntryPoint()
        {
            Console.WriteLine("This is a message from C#");
            MessageBox(0, "C# is good", "hello world", 0);
        }
    }
}

C++ :

#include <stdio.h>
#include <Windows.h>

int main(int argc, char **argv) {
    if (argv[1] == NULL) {
        printf("Usage : dll_executor <DLL_PATH>\n");
        return -1;
    }

    char* Dll_Path = argv[1];
    HMODULE hModule = LoadLibraryA(Dll_Path);
    if (hModule == NULL) {
        printf("Failed to load the dll.\n");
    }

    LPCSTR Function_To_Execute = "DllEntryPoint"; // Function to execute in the dll
    
    HANDLE hThread = CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE)GetProcAddress(hModule, Function_To_Execute), NULL, 0, NULL);
    if (hThread == NULL) {
        printf("Failed to create thread.\n");
    }

    printf("Dll Executed!\n");
    WaitForSingleObject(hThread, INFINITE);
    CloseHandle(hThread);
    FreeLibrary(hModule);

    return 0;
}

#include <stdio.h>
#include <Windows.h>

int main(int argc, char **argv) {
    if (argv[1] == NULL) {
        printf("Usage : dll_executor <DLL_PATH>\n");
        return -1;
    }

    char* Dll_Path = argv[1];
    HMODULE hModule = LoadLibraryA(Dll_Path);
    if (hModule == NULL) {
        printf("Failed to load the dll.\n");
    }

    LPCSTR Function_To_Execute = "DllEntryPoint"; // Function to execute in the dll
    
    HANDLE hThread = CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE)GetProcAddress(hModule, Function_To_Execute), NULL, 0, NULL);
    if (hThread == NULL) {
        printf("Failed to create thread.\n");
    }

    printf("Dll Executed!\n");
    WaitForSingleObject(hThread, INFINITE);
    CloseHandle(hThread);
    FreeLibrary(hModule);

    return 0;
}

The cpp code says that it got executed but it doesn't really

29 Replies

Jimmacle•3mo ago

you can't do this this way, C# isn't compiled to native code there's a whole runtime you need to set up first

Silme94•3mo ago

how do i compile to native code

Jimmacle•3mo ago

you can't, not in a way that will work for this what's your actual goal?

Silme94•3mo ago

just to make a C# library for C++

Jimmacle•3mo ago

but why

Jimmacle•3mo ago

i mean, if you really want to this is a starting point https://learn.microsoft.com/en-us/dotnet/core/tutorials/netcore-hosting

Write a custom .NET runtime host - .NET

Learn to host the .NET runtime from native code to support advanced scenarios that require controlling how the .NET runtime works.

leowest•3mo ago

this might be of your interest https://github.com/3F/DllExport/wiki/Quick-start

GitHub

Quick start

.NET DllExport with .NET Core support (aka 3F/DllExport aka DllExport.bat) - 3F/DllExport

arion•3mo ago

You could make a native aot library https://luxeengine.com/csharp-to-native-library/

Silme94•3mo ago

it does nothing when i run the code

#include <stdio.h>
#include <Windows.h>

typedef void(__cdecl *DllEntryPoint)();

int main(int argc, char **argv) {

    HMODULE lib = LoadLibrary("InternalTest.dll");
    if (lib == NULL) {
        printf("Failed to load the dll.\n");
    }

    auto func = (DllEntryPoint)GetProcAddress(lib, "DllEntryPoint");
    func();

    printf("Dll Executed!\n");

    FreeLibrary(lib);

    return 0;
}

#include <stdio.h>
#include <Windows.h>

typedef void(__cdecl *DllEntryPoint)();

int main(int argc, char **argv) {

    HMODULE lib = LoadLibrary("InternalTest.dll");
    if (lib == NULL) {
        printf("Failed to load the dll.\n");
    }

    auto func = (DllEntryPoint)GetProcAddress(lib, "DllEntryPoint");
    func();

    printf("Dll Executed!\n");

    FreeLibrary(lib);

    return 0;
}

using System.Runtime.InteropServices;
using System;
using System.Diagnostics;

namespace InternalTest
{
    public class Class1
    {
        
        [DllImport("user32.dll")]
        public static extern int MessageBox(int hWnd, string text, string caption, uint type);

        [DllExport(CallingConvention = CallingConvention.StdCall)]
        static void DllEntryPoint()
        {
            Console.WriteLine("This is a message from C#");
            MessageBox(0, "C# is good", "hello world", 0);            
        }
    }
}

using System.Runtime.InteropServices;
using System;
using System.Diagnostics;

namespace InternalTest
{
    public class Class1
    {
        
        [DllImport("user32.dll")]
        public static extern int MessageBox(int hWnd, string text, string caption, uint type);

        [DllExport(CallingConvention = CallingConvention.StdCall)]
        static void DllEntryPoint()
        {
            Console.WriteLine("This is a message from C#");
            MessageBox(0, "C# is good", "hello world", 0);            
        }
    }
}

it dont even print "Dll Executed!" thanks for ur response, ill try that

leowest•3mo ago

well that doesn't look like its using that library it has videos and abunch of step by steps u can look into

Silme94•3mo ago

it stops when calling the function

Loading dll...
lib=c3540000...
Executing Dll...

Loading dll...
lib=c3540000...
Executing Dll...

#include <stdio.h>
#include <Windows.h>

typedef void(__cdecl *DllEntryPoint)();

int main(int argc, char **argv) {
    printf("Loading dll...\n");
    HMODULE lib = LoadLibrary("InternalTest.dll");
    if (lib == NULL) {
        printf("Failed to load the dll.\n");
    }
    printf("lib=%x...\n", lib);
    auto func = (DllEntryPoint)GetProcAddress(lib, "DllEntryPoint");
    printf("Executing Dll...\n");
    func();

    printf("Dll Executed!\n");

    FreeLibrary(lib);

    return 0;
}

#include <stdio.h>
#include <Windows.h>

typedef void(__cdecl *DllEntryPoint)();

int main(int argc, char **argv) {
    printf("Loading dll...\n");
    HMODULE lib = LoadLibrary("InternalTest.dll");
    if (lib == NULL) {
        printf("Failed to load the dll.\n");
    }
    printf("lib=%x...\n", lib);
    auto func = (DllEntryPoint)GetProcAddress(lib, "DllEntryPoint");
    printf("Executing Dll...\n");
    func();

    printf("Dll Executed!\n");

    FreeLibrary(lib);

    return 0;
}

leowest•3mo ago

yeah but your code is not using the library from waht u showed...

Silme94•3mo ago

wdym

leowest•3mo ago

I linked u a library, with their quick start on how to use it and ur just quoting me on not working with some code that doesn't look like what the library provides

Silme94•3mo ago

i clicker on " C++ ❤ C# (+📹)" the link at the right

leowest•3mo ago

its not just code u need to use the library u understand that right?

Silme94•3mo ago

arion•3mo ago

https://cdn.discordapp.com/attachments/1166785753481760829/1228827214082998362/b12bd993-0fb2-4f91-b812-77aef2c45119_13-04-2024.png?ex=662d7586&is=661b0086&hm=b6ed3fd9d74d1fc023e7516a55540d603c838e69d3a29f010bfa3866a6ae3809&

Silme94•3mo ago

it dont work

using System.Runtime.InteropServices;
using System;
using System.Diagnostics;

namespace InternalTest
{
    public class Class1
    {
        
        [DllImport("user32.dll")]
        public static extern int MessageBox(int hWnd, string text, string caption, uint type);

        [UnmanagedCallersOnly(EntryPoint = "hello_world")]
        static void DllEntryPoint()
        {
            Console.WriteLine("This is a message from C#");
            MessageBox(0, "C# is good", "hello world", 0);            
        }
    }
}

using System.Runtime.InteropServices;
using System;
using System.Diagnostics;

namespace InternalTest
{
    public class Class1
    {
        
        [DllImport("user32.dll")]
        public static extern int MessageBox(int hWnd, string text, string caption, uint type);

        [UnmanagedCallersOnly(EntryPoint = "hello_world")]
        static void DllEntryPoint()
        {
            Console.WriteLine("This is a message from C#");
            MessageBox(0, "C# is good", "hello world", 0);            
        }
    }
}

#include <stdio.h>
#include <Windows.h>

typedef void (*VoidFN)();

int main(int argc, char **argv) {
    void* library = LoadLibraryA("InternalTest.dll");
    VoidFN fn = (VoidFN)GetProcAddress((HMODULE)library, "hello_world");
    fn();
    return 0;
}

#include <stdio.h>
#include <Windows.h>

typedef void (*VoidFN)();

int main(int argc, char **argv) {
    void* library = LoadLibraryA("InternalTest.dll");
    VoidFN fn = (VoidFN)GetProcAddress((HMODULE)library, "hello_world");
    fn();
    return 0;
}

oh this is working for u

arion•3mo ago

did you build it like the article said?

arion•3mo ago

https://cdn.discordapp.com/attachments/1166785753481760829/1228827589645308004/ee3297bd-edb2-428b-80ca-51b63c67eb2e_14-04-2024.png?ex=662d75df&is=661b00df&hm=2b5449547074250817f01ba08903c7fbf78ffafc1c703d9b6d0ee9ed80671dee&

Silme94•3mo ago

yeah, i added <PublishAOT> to true but this is the same thing as compiling in vs code ? tbh i compiled with vs i will try that

arion•3mo ago

publishing is not the same as compiling

Silme94•3mo ago

yeah my bad

arion•3mo ago

just remember, its in your publish folder (mine in the screenshot is in C:\Users\Dawn\RiderProjects\NAOTTest\NAOTTest\bin\Release\net7.0\win-x64\publish)

Silme94•3mo ago

@ bro thank you this is working well thanks a lot

arion•3mo ago

:okHand: just remember, native aot (c# native) has some drawbacks, from the top of my head um, reflection is a nono, Json serialization gets harder, and some other things, i forgor though i could be wrong, im a whole version of .net behind on native aot, they might have gotten better already

Silme94•3mo ago

/solved !solved bruh

arion•3mo ago

i think its /close or smthn

Gaming

Programming

✅ Using a C# DLL in C++