Problem with CLR / It don't work with Runtime v4.0.30319

[Timm4D]

I have a C++ dll which is calling my C# code after an injection with CLR.

So this is my C++ (dll) code:

#include "stdafx.h"
#include <iostream>
#include <metahost.h>
#include <atlbase.h>
#include <atlcom.h>
#pragma comment(lib, "mscoree.lib")

#define IfFailRet(expr)                { hr = (expr); if(FAILED(hr)) return (hr); }
#define IfNullFail(expr)                { if (!expr) return (E_FAIL); }

extern "C" int __declspec(dllexport) CALLBACK CallClrMethod(
    const WCHAR *AssemblyName,
    const WCHAR *TypeName,
    const WCHAR *MethodName,
    const WCHAR *args,
    LPDWORD pdwResult
)
{
    int hr = S_OK;
    CComPtr<ICLRMetaHost> spHost;
    hr = CLRCreateInstance(CLSID_CLRMetaHost, IID_PPV_ARGS(&spHost));
    CComPtr<ICLRRuntimeInfo> spRuntimeInfo;
    CComPtr<IEnumUnknown> pRunTimes;
    IfFailRet(spHost->EnumerateInstalledRuntimes(&pRunTimes));
    CComPtr<IUnknown> pUnkRuntime;
    while (S_OK == pRunTimes->Next(1, &pUnkRuntime, 0))
    {
        CComQIPtr<ICLRRuntimeInfo> pp(pUnkRuntime);
        if (pUnkRuntime != nullptr)
        {
            spRuntimeInfo = pp;
            break;
        }
    }
    IfNullFail(spRuntimeInfo);

    BOOL bStarted;
    DWORD dwStartupFlags;
    hr = spRuntimeInfo->IsStarted(&bStarted, &dwStartupFlags);
    if (hr != S_OK) // sometimes 0x80004001  not implemented  
    {
        spRuntimeInfo = nullptr; //v4.0.30319 //v2.0.50727
        hr = spHost->GetRuntime(L"v2.0.50727", IID_PPV_ARGS(&spRuntimeInfo));
        bStarted = false;
    }

    CComPtr<ICLRRuntimeHost> spRuntimeHost;
    IfFailRet(spRuntimeInfo->GetInterface(CLSID_CLRRuntimeHost, IID_PPV_ARGS(&spRuntimeHost)));
    if (!bStarted)
    {
        hr = spRuntimeHost->Start();
    }
    hr = spRuntimeHost->ExecuteInDefaultAppDomain(
        AssemblyName,
        TypeName,
        MethodName,
        args,
        pdwResult);
    return hr;
}


int _tmain(int argc, _TCHAR* argv[])
{
    DWORD dwResult;
    HRESULT hr = CallClrMethod(
        L"D:\\Dev\\CSharpDll\\CSharpDll\\bin\\x64\\Debug\\CSharpDll.dll",
        L"CSharpDll.MainClass",
        L"EntryPoint",
        L"Im successfully called from a C++ dll",
        &dwResult);
    return 0;
}

BOOL APIENTRY DllMain(HMODULE hModule,
    DWORD  ul_reason_for_call,
    LPVOID lpReserved
)
{
    switch (ul_reason_for_call)
    {
    case DLL_PROCESS_ATTACH:
        CreateThread(NULL, NULL, (LPTHREAD_START_ROUTINE)_tmain, hModule, NULL, NULL);
        break;
    case DLL_THREAD_ATTACH:
        break;
    case DLL_THREAD_DETACH:
        break;
    case DLL_PROCESS_DETACH:
        break;
    }
    return TRUE;
}

And this is my C# (dll) code:

using System.Windows.Forms;

namespace CSharpDll
{
    public class MainClass
    {
        public static int EntryPoint(string MessageFromCppDll)
        {
            MessageBox.Show(MessageFromCppDll);

            Form form = new MainForm();
            form.ShowDialog();

            return 0;
        }
    }
}

So it works very well for the most programs and games, but not at all. On some programs it happens nothing. The injected c++ dll try to run the c# code, but it happen nothing. My theory is that the c++ dll will create no instance of the c# dll.

But there is one option to fix that: If I change the runtime from v4.0.30319 to v2.0.50727 it works fine.

It don't work:

hr = spHost->GetRuntime(L"v4.0.30319", IID_PPV_ARGS(&spRuntimeInfo));

It work:

hr = spHost->GetRuntime(L"v2.0.50727", IID_PPV_ARGS(&spRuntimeInfo));

And now we come to my "main" problem: I have to decrease the .NET version from 4+ to 3.5 because the CLR V2 only support .NET 2 - 3.5. And this brings problems with my C# (dll) code.

So now I come to my question(s):

1. Why is this not working on all programs and games? (I mean with runtime v4.0.30319). With CLR RunTimeHost v2.0.50727 it works.
2. And how can I fix it or change something in my code to run it.

If you guys have any ideas or code examples, I would be very grateful.

[MikeRohsoft]

I found this, maybe it helps?

IEnumUnknown *installedRuntimes;
hr = pMetaHost->EnumerateInstalledRuntimes(&installedRuntimes);

ICLRRuntimeInfo *runtimeInfo = NULL;
ULONG fetched = 0;
while ((hr = installedRuntimes->Next(1, (IUnknown **)&runtimeInfo, &fetched)) == S_OK && fetched > 0) {
    wchar_t versionString[20];
    DWORD versionStringSize = 20;
    hr = runtimeInfo->GetVersionString(versionString, &versionStringSize);

    // Look for the 4.0 runtime
    if (versionStringSize >= 2 && versionString[1] == '4') {
        break;
    }
}

[Biesi]

Might depend on the operating system you're using or trying to run this on. AFAIK Win 7 etc. only have the 3.5 framework installed, later Windows versions come with higher framework versions.

You could possibly check the Windows Event Log to see if there are any errors logged by the OS/applications