在NPObject - Firefox插件上调用方法出错

我有一个可视化的c++代码(firebreath)，从一个可视化的c#应用程序检索数据。在负数情况下(返回值不带out参数)通信正常，但在正数情况下(返回值不带out参数)显示以下错误。

错误: nproject调用方法错误!

我猜问题出在Visual c#应用程序的out参数上。有人能帮帮我吗?请使用以下代码作为参考。

ngContent.js: (js调用firebreath函数)

function GetDetails(param1, param2) {
  try {
    return document.getElementById("nGCall").ReturnDetails(param1, param2);
  }
  catch (e) {
    alert("Exception Occured " + e.message);
  }
};

nGAPI.cpp: (Firebreath函数调用c#应用程序)

FB::VariantList nGAPI::ReturnDetails(std::wstring& param1, std::wstring& param2)
{
  try {
    InetGuardNPAPI *CSharpInterface = NULL;
    //Open interface to C#
    CoInitialize(NULL);
    HRESULT hr = CoCreateInstance(CLSID_netGuardIEBHO, NULL, CLSCTX_INPROC_SERVER, IID_InetGuardNPAPI, reinterpret_cast<void**>(&CSharpInterface));
    BSTR out1= NULL;
    BSTR out2= NULL;
    BSTR out3= NULL;
    BSTR out4= NULL;
    int returns = CSharpInterface->NPGetDetails(param1.c_str(), param2.c_str(), &out1, &out2, &out3, &out4);
    if (out1 != NULL && out2 != NULL) {
      return FB::variant_list_of(out1)(out2)(out3)(out4);
    } else {
      return FB::variant_list_of();
    }
  } catch (...) {
    MessageBoxW(NULL, L"Exception occured.", L"NG", NULL);
    return FB::variant_list_of();
  }

nGHost.cs: (Visual c#应用程序)

public int NPGetDetails(string param1, string param2, out string out1, out string out2, out string out3, out string out4)
{
  int retValue = 0;
  out1 = null;
  out2 = null;
  out3 = null;
  out4 = null;
  bool userIdentified = IdentifyUser(ngDB, out ngdata);
  if (!userIdentified)
    return retValue;
  try {
    out1 = ngdata.abc;
    out2 = ngdata.def;
    out3 = ngdata.ghi;
    out4 = ngdata.jkl;
    retValue = 1;
  } catch (Exception ex) {
    MessageBox.Show(ex.Message);
  }
  return retValue;
}