It's not everyday you need to host the CLR but when do there is very little information available. This post captures what I've found on the web as well as my own code which works places where other code don't.
The Intention
Host the DotNet CLR (Common Language Runtime) in a C++ program and load a .NET EXE in it; by 'load' I also mean 'run'.
Solutions for far
CppHostCLR on CodePlex
I found this project quite far into google's search results. This project uses the DotNet 4 CLR hosting interfaces to load a .NET DLL and calls a method. For my purposes I modified it a bit to load an EXE and call the Main() method hoping my WPF application will executed - it did not.
CLR Hosting - Customizing the CLR in CodeProject
This project comes pretty close to what I want to do. However this project worked only for console application, it could not load a WPF application.
What worked
Coming to what worked was actually a much simpler code which makes use of the new DotNet4 hosting interfaces and does not make use of an App Domain Manager. It makes use of the ICorRuntimeHost interface to get the default domain using the GetDefaultDomain() method which it then uses to run the EXE using the ExecuteAssembly() method. The main C++ code is given below:
HRESULT HostInClr(LPCTSTR executable)
{
CComPtr pMetaHost;
HRESULT hr = CLRCreateInstance(CLSID_CLRMetaHost, IID_ICLRMetaHost, (LPVOID*)&pMetaHost);
if (FAILED(hr))
{
ShowError(_T("Create meta-host"), GetLastError());
return hr;
}
CComPtr pRuntimeInfo;
hr = pMetaHost->GetRuntime(L"v4.0.30319", IID_ICLRRuntimeInfo, reinterpret_cast(&pRuntimeInfo));
if (FAILED(hr))
{
ShowError(_T("Create runtime-info"), GetLastError());
return hr;
}
CComPtr pRuntimeHost;
hr = pRuntimeInfo->GetInterface(CLSID_CorRuntimeHost, IID_ICorRuntimeHost, reinterpret_cast(&pRuntimeHost));
if (FAILED(hr))
{
ShowError(_T("Create runtime-host"), GetLastError());
return hr;
}
hr = pRuntimeHost->Start();
if (FAILED(hr))
{
ShowError(_T("Start runtime-host"), GetLastError());
return hr;
}
CComPtr pUnknown;
hr = pRuntimeHost->GetDefaultDomain(&pUnknown);
if (FAILED(hr))
{
ShowError(_T("Get default-app-domain"), GetLastError());
return hr;
}
CComPtr appDomainPtr;
hr = pUnknown->QueryInterface(&appDomainPtr.p);
if (FAILED(hr))
{
ShowError(_T("Get app-domain-ptr"), GetLastError());
return hr;
}
LONG dwRetVal;
CComBSTR bsExe(executable);
hr = appDomainPtr->ExecuteAssembly(bsExe, nullptr, &dwRetVal);
if (FAILED(hr))
{
ShowError(L"Execute", GetLastError());
return hr;
}
hr = pRuntimeHost->Stop();
if (FAILED(hr))
{
ShowError(_T("Stop runtime-host"), GetLastError());
return hr;
}
return S_OK;
}
Where to get the full source-code?
The code is available on GitHub at https://github.com/siddharthbarman/ClrHosting.