为什么即使getlasterror为0，为什么clrhosting api也无法正常工作

我试图通过遵循本教程将托管的C＃dll加载到托管的C＃过程中。我在C/C 上进行了相当多的编码，并且对MS Com有工作知识，但是C＃和托管代码对我来说是一个全新的野兽，因此，如果我做错了什么，请原谅。我的系统上有.NET 4.5，这是默认情况下使用的同一运行时（我认为）。到目前为止的代码（主要是从上述链接复制）：

代码-C＃

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace InjectSample
{
    public class Program
    {
        int EntryPoint(String pwzArgument)
        {
            System.Media.SystemSounds.Beep.Play();
            MessageBox.Show(
                "I am a managed app.nn" +
                "I am running inside: [" +
                System.Diagnostics.Process.GetCurrentProcess().ProcessName +
                "]nn" + (String.IsNullOrEmpty(pwzArgument) ?
                "I was not given an argument" :
                "I was given this argument: [" + pwzArgument + "]"));
            return 0;
        }
        static void Main(string[] args)
        {
            Program prog = new Program();
            prog.EntryPoint("hello world");
        }
    }
}

本机代码

#include <metahost.h>
#pragma comment(lib, "mscoree.lib")
#import "mscorlib.tlb" raw_interfaces_only 
    high_property_prefixes("_get","_put","_putref") 
    rename("ReportEvent", "InteropServices_ReportEvent")

#include <strsafe.h>
void ErrorExit(LPCWSTR lpszFunction, DWORD dwLastError) 
{ 
    if(dwLastError == 0) return;
    LPVOID lpMsgBuf;
    LPVOID lpDisplayBuf;
    DWORD dwFlag = FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS;
    FormatMessage( dwFlag, NULL, dwLastError, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), (LPTSTR) &lpMsgBuf, 0, NULL );
    lpDisplayBuf = (LPVOID)LocalAlloc(LMEM_ZEROINIT, (lstrlen((LPCTSTR)lpMsgBuf) + lstrlen((LPCTSTR)lpszFunction) + 40) * sizeof(TCHAR)); 
    StringCchPrintf((LPTSTR)lpDisplayBuf, LocalSize(lpDisplayBuf) / sizeof(TCHAR), TEXT("%s failed with error %d: %s"), lpszFunction, dwLastError, lpMsgBuf); 
    ::MessageBox(NULL, (LPCTSTR)lpDisplayBuf, TEXT("Error"), MB_OK); 
    LocalFree(lpMsgBuf);
    LocalFree(lpDisplayBuf);
}
int wmain(int argc, wchar_t* argv[])
{
    HRESULT hr;
    ICLRMetaHost *pMetaHost = NULL;
    ICLRRuntimeInfo *pRuntimeInfo = NULL;
    ICLRRuntimeHost *pClrRuntimeHost = NULL;
    // build runtime
    hr = CLRCreateInstance(CLSID_CLRMetaHost, IID_PPV_ARGS(&pMetaHost));
    hr = pMetaHost->GetRuntime(L"v4.0.30319", IID_PPV_ARGS(&pRuntimeInfo));
    hr = pRuntimeInfo->GetInterface(CLSID_CLRRuntimeHost, 
        IID_PPV_ARGS(&pClrRuntimeHost));
    // start runtime
    hr = pClrRuntimeHost->Start();
    // execute managed assembly
    DWORD pReturnValue;
    SetLastError(0);
    hr = pClrRuntimeHost->ExecuteInDefaultAppDomain(
        L"C:\Temp\InjectSample.exe", 
        L"InjectExample.Program", 
        L"int EntryPoint(String pwzArgument)", 
        L"hello .net runtime", 
        &pReturnValue);
    ErrorExit(L"ExecuteInDefaultAppDomain()", GetLastError());
    // free resources
    pMetaHost->Release();
    pRuntimeInfo->Release();
    pClrRuntimeHost->Release();
    return 0;
}

问题

现在问题是当我执行本机代码时，GetLastError()返回0。那是在致电ExecuteInDefaultAppDomain()之后。根据codeproject链接，它应该显示对话框，但在我的情况下，它没有显示任何内容。

我不确定问题，任何建议/指针都会有所帮助。谢谢。