Question

我在C ++ / CLI包装器中使用了C＃dll。 dll返回一个ADODB :: Recordset ^对象，但是我需要包装器来返回一个_RecordsetPtr对象。我怎样才能在两者之间进行转换？

这是我到目前为止所拥有的。我遇到的问题是，在for循环的最后一行之后，该函数跳转到return语句并结束。它不会继续循环，并且它不会击中＆＃34; Object ^ rows =。。＆＃34;线。

_RecordsetPtr TraserInterface::GetDistributorRecordset()
{
    ADODB::Recordset^ recordset = TraserWrapper::Instance->traserInterface->DistributorRecordset;
    ADODB::Fields^ fields = ((ADODB::RecordsetClass^)recordset)->default;
    HRESULT hr;
    _RecordsetPtr recordsetPtr("ADODB.Recordset");
    for (int i = 0; i < fields->Count; i++)
    {
        ADODB::Field^ field = fields[i];
        String^ fieldName = field->Name;
        _bstr_t bstrName = MarshalString(fieldName).c_str();
        int type = (int)field->Type;
        int definedSize = field->DefinedSize;
        int fieldAttrib = field->Attributes;
        hr = recordsetPtr->Fields->Append(bstrName, (DataTypeEnum)type, definedSize, (FieldAttributeEnum)fieldAttrib);
    }
    Object^ rows = recordset->GetRows((int)ADODB::GetRowsOptionEnum::adGetRowsRest, (Object^)ADODB::BookmarkEnum::adBookmarkFirst, (Object^)fields);
    // loop through rows and populate recordsetPtr . . .
    return recordsetPtr;
}

Answer 1

感谢Hans Passant，我找到了解决方案：

_RecordsetPtr TraserInterface::GetDistributorRecordset()
{
    ADODB::Recordset^ recordset = TraserWrapper::Instance->traserInterface->DistributorRecordset);
    IntPtr recordsetIntPtr = Marshal::GetIUnknownForObject(recordset);
    IUnknown* unknown = (IUnknown*)(void*)recordsetIntPtr;
    _RecordsetPtr recordsetPtr(unknown);
    return recordsetPtr;
}

将ADODB :: Recordset ^转换为_RecordsetPtr

1 个答案: