Is it possible to host the CLR in a C program? - c

Question

Every example I can find is in C++, but I'm trying to keep my project in C. Is it even possible to host the CLR in a C program?
If so, can you point me to an example?

Answer 1

As the above comments hint, there is a set of COM APIs for hosting the CLR, and you should be able to call these COM APIs from both C and C++.
As an example, below is a quick piece of (untested) C code that shows how to start up the CLR and execute a static method of a class in a managed assembly (which takes in a string as an argument and returns an integer). The key difference between this code and its C++ counterpart is the definition of COBJMACROS and the use of the <type>_<method> macros (e.g. ICLRRuntimeHost_Start) to call into the CLR-hosting COM interface. (Note that COBJMACROS must be defined prior to #include'ing mscoree.h to make sure these utility macros get defined.)
#include <windows.h>
#define COBJMACROS
#include <mscoree.h>
int main(int argc, char **argv)
{
HRESULT status;
ICLRRuntimeHost *Host;
BOOL Started;
DWORD Result;
Host = NULL;
Started = FALSE;
status = CorBindToRuntimeEx(
NULL,
NULL,
0,
&CLSID_CLRRuntimeHost,
&IID_ICLRRuntimeHost,
(PVOID *)&Host
);
if (FAILED(status)) {
goto cleanup;
}
status = ICLRRuntimeHost_Start(Host);
if (FAILED(status)) {
goto cleanup;
}
Started = TRUE;
status = ICLRRuntimeHost_ExecuteInDefaultAppDomain(
Host,
L"c:\\path\\to\\assembly.dll",
L"MyNamespace.MyClass",
L"MyMethod",
L"some string argument to MyMethod",
&Result
);
if (FAILED(status)) {
goto cleanup;
}
// inspect Result
// ...
cleanup:
if (Started) {
ICLRRuntimeHost_Stop(Host);
}
if (Host != NULL) {
ICLRRuntimeHost_Release(Host);
}
return SUCCEEDED(status) ? 0 : 1;
}
This sample should work with .NET 2.0+, although it looks like .NET 4.0 (not yet released) has deprecated some of these APIs in favor of a new set of APIs for hosting the CLR. (And if you need this to work with .NET 1.x, you need to use ICorRuntimeHost instead of ICLRRuntimeHost.)