如何实现将 _Recordset ** 参数发送到 COM+应用

发布于 2024-11-02 03:04:12 字数 926 浏览 4 评论 0原文

我有一个 COM+ VB6 应用程序，我使用 MIDL 编译器生成了一个头文件。标头包含以下定义：

   virtual /* [id] */ HRESULT STDMETHODCALLTYPE Gett( 
    /* [in] */ BSTR sPostCode,
    /* [in] */ BSTR sSurname,
    /* [retval][out] */ _Recordset **__MIDL_0012) = 0;

在调用此 ive 导入的 C++ 客户端调用中，

    #import "C:\Program files\Common Files\System\Ado\msado15.dll" 
rename("EOF", "ADOEOF")

然后按如下方式调用 GetAddress 函数：

void AddressLookup::GetAddress(_bstr_t postCode, _bstr_t address)
{
   ADODB::_RecordsetPtr recordset;
   HRESULT hr = recordset.CreateInstance(__uuidof(ADODB::Recordset));

   m_pIAddressLookup->Gett(postCode, address, recordset);
}

但我不断收到此编译器错误：

AddressLookup.cpp(20)：错误 C2664： '_AddressLookup::Gett' : 不能将参数 3 转换为 'ADODB::_RecordsetPtr' 到 '_Recordset ** ' 没有可用的用户定义转换运算符可以执行此转换或运算符无法调用

原文

I have a COM+ VB6 application, I generated a header file using the MIDL compiler.
The header contains the following definition:

   virtual /* [id] */ HRESULT STDMETHODCALLTYPE Gett( 
    /* [in] */ BSTR sPostCode,
    /* [in] */ BSTR sSurname,
    /* [retval][out] */ _Recordset **__MIDL_0012) = 0;

In my c++ client call that calls this ive imported

    #import "C:\Program files\Common Files\System\Ado\msado15.dll" 
rename("EOF", "ADOEOF")

The GetAddress function is then being called as follows:

void AddressLookup::GetAddress(_bstr_t postCode, _bstr_t address)
{
   ADODB::_RecordsetPtr recordset;
   HRESULT hr = recordset.CreateInstance(__uuidof(ADODB::Recordset));

   m_pIAddressLookup->Gett(postCode, address, recordset);
}

but i keep geting this compiler error:

AddressLookup.cpp(20) : error C2664:
'_AddressLookup::Gett' : cannot
convert parameter 3 from
'ADODB::_RecordsetPtr' to '_Recordset
** '
No user-defined-conversion operator available that can perform
this conversion, or the operator
cannot be called

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惯饮孤独 2024-11-09 03:04:12

这：

m_pIAddressLookup->Gett(postCode, address, recordset);

应该是

m_pIAddressLookup->Gett(postCode, address, &recordset);

（注意 recordset 前面的 & - 这意味着“获取地址” - 如果您显然使用智能指针，这将调用重载operator&() 这将为您提供存储在智能指针内的接口指针的地址。

This:

m_pIAddressLookup->Gett(postCode, address, recordset);

should be

m_pIAddressLookup->Gett(postCode, address, &recordset);

(note & in front of recordset - it means "take address of" - in case of the smart pointer you're obviously using this will call overloaded operator&() and this will give you the address of the interface pointer stored inside the smart pointer).

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