Question

我有一个旧的ActiveX DLL，它使用struct作为参数引发一些事件：

HRESULT Fire_OnError( T_ErrorInfo * error_info )
{
  //forward declare the IID of the UDTVariable structure
  const IID T_ErrorInfo_IID = { 0xBF5573C3, 
                                0x28DD,
                                0x11DE, {
                                         0xAB,
                                         0xF5, 
                                         0x00,
                                         0x50,
                                         0x56,
                                         0xC0,
                                         0x00,
                                         0x08
                                        }
                              };

  HRESULT hr = S_OK;
  T * pThis = static_cast<T *>(this);
  int cConnections = m_vec.GetSize();

  IRecordInfo *pRI;

  hr = GetRecordInfoFromGuids(LIBID_AxEuroATLib, 
                              AX_VER_MAJOR, 
                              AX_VER_MINOR, 
                              LOCALE_USER_DEFAULT, 
                              T_ErrorInfo_IID, 
                              &pRI);
  CComVariant avarParams[1];
  avarParams[0].vt = VT_RECORD;
  avarParams[0].pvRecord = error_info;
  avarParams[0].pRecInfo = pRI;
  pRI = NULL;

  DISPPARAMS params = { avarParams, NULL, 1, 0 };

  for (int iConnection = 0; iConnection < cConnections; iConnection++)
  {
    pThis->Lock();
    CComPtr<IUnknown> punkConnection = m_vec.GetAt(iConnection);
    pThis->Unlock();

    CComQIPtr< IDispatch, &IID_IDispatch > pDispatch( punkConnection );

    if (pDispatch != NULL)
      hr = pDispatch->Invoke(1, IID_NULL, LOCALE_USER_DEFAULT, DISPATCH_METHOD, &params, NULL, NULL, NULL);
  }

  return hr;
}

这里，error_info结构在VT_VARIANT中封装了VT_RECORD类型。

现在，在管理方面，我只是：

_MyObj.OnError += _MyObj_OnError;

void _MyObj_OnError(ref T_ErrorInfo error_info)
{      
}

但是，当COM调用Invoke（）时，我得到两个例外：

A first chance exception of type 'System.ArgumentException' occurred in mscorlib.dll
Additional information: Impossibile eseguire il mapping del record specificato su una classe di valori gestita.


A first chance exception of type 'System.NotImplementedException' occurred in mscorlib.dll
Additional information: Variant.ToObject cannot handle VT_RECORD

修改
T_ErrorInfo定义如下：

typedef 
[ 
    uuid(6C3EB8FD-565E-11E1-B86C-0800200C9A66),
    version(1.0),
]
enum E_ERRORS {
  ....
  errors list
  ....
} E_ERRORS;

typedef 
[ 
    uuid(BF5573C3-28DD-11DE-ABF5-005056C00008), 
    version(1.0),

    helpstring("TErrorInfo structure")
]
struct T_ErrorInfo
{
  E_ERRORS err_no;
  BSTR     description;
  BSTR     routine;
}T_ErrorInfo;

有没有办法“绕过”并解决这个问题？

提前致谢。

使用VT_VARIANT + VT_RECORD参数

0 个答案: