How to call managed c# functions from unmanaged c++
A:
RE: How to call managed C# code from an unmanaged C++ application?
Calling Managed .NET C# COM Objects from Unmanaged C++ Code ...
http://www.codeproject.com/KB/cs/ManagedCOM.aspx
Wrapping a managed C# DLL in a unmanaged C++ project : dll .
http://www.experts-exchange.com/Programming/Languages/.NET/Q_22006727.html
ratty
2010-04-27 09:26:21
I followed second link which you have provided and successfully compile the cpp file but failed to run it . It is failing at CreateInstance() using smartpointer..... so iam unable to call functions of c# dll
2010-04-27 09:35:56
+1
A:
Or use a project of mine that allows C# to create unmanaged exports. Those can be consumed as if they were written in a native language.
Robert Giesecke
2010-04-27 09:57:46
+1
A:
I used COM interop first, but by now I switched to IJW (it just works), as it is a lot simpler. I have a wrapper C++/CLR DLL (compile with /clr).
A simple example (using statics to make the calls easier):
namespace MyClasses
{
public class MyClass
{
public static void DoSomething()
{
MessageBox.Show("Hello World");
}
}
}
In the DLL I can reference namespaces as follows:
using namespace MyClasses;
And call it:
__declspec(dllexport) void CallManagedCode()
{
MyClass::DoSomething();
}
Now you have an unmanaged DLL export "CallManagedCode" which calls into the managed code.
Of course, you also have to convert data between the managed/unmanaged boundary. Starting with VS2008, Microsoft includes a marshal-helper for converting between unmanaged and managed types. See http://msdn.microsoft.com/en-us/library/bb384865.aspx
Daniel Rose
2010-04-27 10:23:57
You do not really have to go down that route manually. Check out the link in my reply. It is entirely possible to have the counterpart of DllImport in c#, including all the marshaling goodness that comes with .Net. My MSBuild task adds the appropriate vt-fixups after the build and you do not need to deploy another assembly...
Robert Giesecke
2010-04-27 13:00:30
I tried it: The DLL has the exports. However, how am I supposed to use it? I did not find a .lib to allow me to link to the DLL.
Daniel Rose
2010-04-28 12:33:32
I don't use C++, but I guess it isn't any different than like you would for any library that doesn't come with C/C++ headers: Write the header for the functions you want to import yourself. As i said, I don#t use C++. It is pretty straightforward from C or Delphi.
Robert Giesecke
2010-04-28 16:10:11
The headers isn't the problem. To link to the library you need a .lib, otherwise you'd have to use LoadLibrary() and GetProcAddress() for every call. I "solved" it by manually generating a .def and generating a .lib from that, as in http://support.microsoft.com/kb/131313Also, having a method call itself failed (standard use case when making the call UI-thread-safe). Could I perhaps contact you via email? I didn't find an address anywhere.
Daniel Rose
2010-04-28 16:57:27
+1
A:
I used C++/CLI wrapper classes described here and it was relatively easy to implement.
Simon
2010-04-27 10:34:02