Hello, programmers.

How can I use the code in a managed dll from a standard Dll,
without using COM ?

Thanxs in advance

Bruno Neves Pires Silva

Bruno Neves Pires Silva wrote:
> How can I use the code in a managed dll from a standard Dll,
> without using COM ?
>
Use C++/CLI and export plain old unmanaged functions that wrap around your
managed code.

--
J.

On 11 dez, 17:01, Jeroen Mostert <jmost...@xs4all.nl> wrote:
> Bruno Neves Pires Silva wrote:> * *How can I use the code in a managed dll from a standard Dll,
> > without using COM ?
>
> Use C++/CLI and export plain old unmanaged functions that wrap around your
> managed code.
>
> --
> J.

Have you tried to do this before, Jeroen?

Can you post a example? I have tried the following code, but it didnt
work:

#pragma once

using namespace System;
using namespace System::Windows::Forms;

namespace MixedDllTest1 {

public ref class Class1
{
public:

static void Test()
{
System::Windows::Forms::MessageBox::Show("This is a
test");
}
};
}
extern "C" void __declspec(dllexport) DllTest()
{
MixedDllTest1::Class1::Test();
}

#define far
typedef void far *LPVOID;

int __stdcall dllMain( void *hModule,
unsigned long ul_reason_for_call,
LPVOID lpReserved
)
{
return 1;
}


#define DllEntryPoint

Bruno Neves Pires Silva wrote:
> On 11 dez, 17:01, Jeroen Mostert <jmost...@xs4all.nl> wrote:
>> Bruno Neves Pires Silva wrote:> How can I use the code in a managed dll from a standard Dll,
>>> without using COM ?
>> Use C++/CLI and export plain old unmanaged functions that wrap around your
>> managed code.
>>
>
> Have you tried to do this before, Jeroen?
>
No, never. I have boundless confidence in this working, though. :-)

It turns out my advice is misleading; you don't export unmanaged functions
since you can't call managed code from unmanaged functions (duh). Exporting
the managed functions directly works.

> Can you post a example?

Yes. I'm going to go command-line, if you don't mind, as it's more
reproducible than project files. You may have to puzzle around a bit if you
want to use the GUI to achieve the same results.

We'll have three artifacts: a managed DLL, an unmanaged DLL linking to the
managed DLL and a little EXE to call a function in the unmanaged DLL.

ManagedLibrary.cpp:

using namespace System;

ref class Foo {
public:
static void Test() {
Console::WriteLine("Hello from the managed world.");
}
};

extern "C" __declspec(dllexport) void __stdcall test(void) {
Foo::Test();
}

UnmanagedLibrary.cpp:

#include <stdio.h>
extern "C" __declspec(dllimport) void __stdcall ManagedHello(void);

extern "C" __declspec(dllexport) void __stdcall hello(void) {
printf("Hello from the unmanaged world.\n");
ManagedHello();
}

program.cpp:

#include <stdio.h>
extern "C" __declspec(dllimport) void __stdcall hello(void);

int main() {
hello();
}


Now let's link it all together. First the managed DLL:

cl /clr ManagedLibrary.cpp /link /dll /out:ManagedLibrary.dll

We're not done! We need to embed the library manifest in the DLL, because
for some reason the linker won't do it for us:

mt /manifest ManagedLibrary.dll.manifest
/outputresource:ManagedLibrary.dll;#2

Without this step, you will get CRT initialization errors. Now the unmanaged
DLL:

cl UnmanagedLibrary.cpp ManagedLibrary.lib /link /dll
/out:UnmanagedLibrary.dll

Finally the EXE:

cl program.cpp UnmanagedLibrary.lib

Running the EXE:

Hello from the unmanaged world.
Hello from the managed world.

And that's all there is to it! Well, when it works. :-)

--
J.

"Jeroen Mostert" <(E-Mail Removed)> wrote in message
news:4942c90a$0$194$(E-Mail Removed)...
> Bruno Neves Pires Silva wrote:
>> On 11 dez, 17:01, Jeroen Mostert <jmost...@xs4all.nl> wrote:
>>> Bruno Neves Pires Silva wrote:> How can I use the code in a managed
>>> dll from a standard Dll,
>>>> without using COM ?
>>> Use C++/CLI and export plain old unmanaged functions that wrap around
>>> your
>>> managed code.
>>>
>>
>> Have you tried to do this before, Jeroen?
>>
> No, never. I have boundless confidence in this working, though. :-)
>
> It turns out my advice is misleading; you don't export unmanaged functions
> since you can't call managed code from unmanaged functions (duh).
> Exporting

Well, you can as long as they haven't got any managed types in the
signature, using a variety of mechanisms, such as function prototypes, dll
imports, function pointers, etc.

> the managed functions directly works.