COM Map Global Functions
These functions provide support for COM Map IUnknown implementations.
| Function | Description |
|---|---|
| AtlInternalQueryInterface | Delegates to the IUnknown of a nonaggregated object. |
| InlineIsEqualIUnknown | Generates efficient code for comparing interfaces against IUnknown. |
Requirements
Header: atlbase.h
AtlInternalQueryInterface
Retrieves a pointer to the requested interface.
HRESULT AtlInternalQueryInterface(
void* pThis,
const _ATL_INTMAP_ENTRY* pEntries,
REFIID iid,
void** ppvObject);
Parameters
pThis
[in] A pointer to the object that contains the COM map of interfaces exposed to QueryInterface.
pEntries
[in] An array of _ATL_INTMAP_ENTRY structures that access a map of available interfaces.
iid
[in] The GUID of the interface being requested.
ppvObject
[out] A pointer to the interface pointer specified in iid, or NULL if the interface is not found.
Return Value
One of the standard HRESULT values.
Remarks
AtlInternalQueryInterface only handles interfaces in the COM map table. If your object is aggregated, AtlInternalQueryInterface does not delegate to the outer unknown. You can enter interfaces into the COM map table with the macro COM_INTERFACE_ENTRY or one of its variants.
Example
// MyTimerProc is a callback function passed to SetTimer()
VOID CALLBACK MyTimerProc(HWND /*hwnd*/, UINT /*uMsg*/, UINT /*idEvent*/,
DWORD /*dwTime*/)
{
LPDISPATCH pDisp = NULL;
// gpMyCtrl is a global variable of type CMyCtrl*
// _GetEntries() is a static function you get with BEGIN_COM_MAP()
AtlInternalQueryInterface (gpMyCtrl, CMyCtrl::_GetEntries(), IID_IDispatch,
(LPVOID*)&pDisp);
//...
pDisp->Release ();
}
InlineIsEqualIUnknown
Call this function, for the special case of testing for IUnknown.
BOOL InlineIsEqualUnknown(REFGUID rguid1);
Parameters
rguid1
[in] The GUID to compare to IID_IUnknown.