Unable load CLR from Visual C++ project with /clr option

Question

I am trying to create a Visual C++ Win32 Console application with following configuration: OS : Windows 7 Visuals Studio : VS 2012 Common Language Runtime Support : Common Language Runtime Support(/clr[Project Properties].

Also i have created a Visual C# WPF application and use that dll to use it from the below mentioned c++ program.

I follow all the instructions from this link: https://code.msdn.microsoft.com/CppHostCLR-e6581ee0

Problem is i am not able to start the CLR ie ICLRRunTimeHost:Start method returns 0x1 instead of 0x0.Please help/guide me to solve my error and if my code is conceptually wrong please guide me for the same.

Please find my code pasted below :

#include "stdafx.h"
#include <metahost.h>
#include <mscoree.h> 
//#include <Windows.h>

//#using <WpfWithoutService.dll>
//using namespace System;
//using namespace System::Threading;

//using namespace WpfWithoutService;

#pragma comment(lib, "mscoree.lib")
/*ref class MainWinClass
{
public:
    void MainForm()
    {
        MainWindow^ mainwin = gcnew MainWindow();
        //mainwin->Activate();
        //mainwin->InitializeComponent();
    }
};*/

int _tmain(int argc, _TCHAR* argv[])
{
    HRESULT hr; 
    //BOOL fLoadable;

    ICLRMetaHost *pMetaHost = NULL;
    LPCWSTR pwzVersion = (LPCWSTR)"v4.0.30319";


    //hr = CLRCreateInstance(CLSID_CLRMetaHost, IID_ICLRMetaHost, (LPVOID*)&pMetaHost); 
    hr = CLRCreateInstance(CLSID_CLRMetaHost, IID_PPV_ARGS(&pMetaHost));
    if (FAILED(hr)) 
    { 
        wprintf(L"CLRCreateInstance failed w/hr 0x%08lx\n", hr); 
    }

    ICLRRuntimeInfo *pRuntimeInfo = NULL; 
// Get the ICLRRuntimeInfo corresponding to a particular CLR version.
    //hr = pMetaHost->GetRuntime(L"v4.0.30319", IID_ICLRRuntimeInfo, (LPVOID *)&pRuntimeInfo); 
    hr = pMetaHost->GetRuntime(L"v4.0.30319", IID_PPV_ARGS(&pRuntimeInfo)); 
    if (FAILED(hr)) 
    { 
        wprintf(L"ICLRMetaHost::GetRuntime failed w/hr 0x%08lx\n", hr); 
        //goto Cleanup; 
    } 


/*Check if the specified runtime can be loaded into the process. This  
// method will take into account other runtimes that may already be  
// loaded into the process and set pbLoadable to TRUE if this runtime can  
// be loaded in an in-process side-by-side fashion.  

    hr = pRuntimeInfo->IsLoadable(&fLoadable); 
    if (FAILED(hr)) 
    { 
        wprintf(L"ICLRRuntimeInfo::IsLoadable failed w/hr 0x%08lx\n", hr); 
        //goto Cleanup; 
    } 


    if (!fLoadable) 
    { 
        wprintf(L".NET runtime %s cannot be loaded\n", "4.0.30319.18063"); 
        //goto Cleanup; 
    }*/


// Load the CLR into the current process and return a runtime interface  pointer. 
    ICLRRuntimeHost *pClrRuntimeHost = NULL;
    hr = pRuntimeInfo->GetInterface(CLSID_CLRRuntimeHost, IID_PPV_ARGS(&pClrRuntimeHost)); 
    if (FAILED(hr)) 
    { 
        wprintf(L"ICLRRuntimeInfo::GetInterface failed w/hr 0x%08lx\n", hr); 
    }


// Start the CLR.
    if (hr == S_OK)
    {
        hr = pClrRuntimeHost->Start(); 
        if (FAILED(hr)) 
        { 
            wprintf(L"CLR failed to start w/hr 0x%08lx\n", hr); 
            //goto Cleanup; 
        }
    }

//Load an assembly and call the required function
    if (hr == S_OK) // if CLR is started successfully
    {
        DWORD dwRet;
        hr = pClrRuntimeHost->ExecuteInDefaultAppDomain(L"WpfWithoutService.dll", L"WpfWithoutService.MainWindow", L"InitializeComponent", NULL, &dwRet); 
        if (FAILED(hr)) 
        { 
            wprintf(L"CLR failed to start w/hr 0x%08lx\n", hr); 
        } 
    }


    if (pMetaHost) 
    { 
        pMetaHost->Release(); 
        pMetaHost = NULL; 
    } 
    if (pRuntimeInfo) 
    { 
        pRuntimeInfo->Release(); 
        pRuntimeInfo = NULL; 
    } 
    if (pClrRuntimeHost) 
    { 
        // Please note that after a call to Stop, the CLR cannot be  
        // reinitialized into the same process. This step is usually not  
        // necessary. You can leave the .NET runtime loaded in your process. 
        //wprintf(L"Stop the .NET runtime\n"); 

            pClrRuntimeHost->Stop()
            pClrRuntimeHost->Release(); 
            pClrRuntimeHost = NULL; 

    } 


    return 0;
}

Answer 1

ICLRRunTimeHost:Start method returns 0x1 instead of 0x0

That is S_FALSE, returned when the CLR is already running. You can't start it twice.

with following configuration ... Common Language Runtime Support

That is not appropriate, it forces the CLR to get loaded and initialized before this code starts running. You only write CLR hosting code like this in a native C++ program that is not built with /clr.

Or in other words, you don't need to write this code at all. And there's no visible reason why you'd want to from the snippet. You can achieve the exact same thing by using Reflection, starting with Assembly::Load(). Or simpler yet, by adding a reference to that assembly. Actual intention is hard to reverse-engineer. If there actually is one then just set the /clr option back to "No".