CA_ServerAggregateObject
HRESULT CA_ServerAggregateObject (CAServerObjHandle serverObjectHandle, const IID *interfaceIdToAggregate, IUnknown *innerObjectIUnknown);
Purpose
Aggregates another object's interface in the object whose handle is passed in the first parameter.
 |
Note Call this function only when the aggregating object (the outer object) is being created, that is, only in response to the CA_SERVER_EVENT_OBJECT_CREATE event in the aggregating object's callback function. |
Example Code
The following code demonstrates aggregation.
HRESULT CVIFUNC OuterObjCb (CAServerObjHandle objHandle, const CLSID *pClsid, int
event, void *callbackData)
{
HRESULT hr = S_OK;
IUnknown *pUnkAgg = NULL;
IUnknown *pUnk = NULL;
if (event == CA_SERVER_EVENT_OBJECT_CREATE) {
caErrChk (CA_ServerGetIfaceFromObjHandle (objHandle,&IID_IUnknown,&pUnk));
caErrChk (CA_ServerCreateObject (&CLSID_InnerObj, pUnk,&IID_IUnknown,&pUnkAgg));
caErrChk (CA_ServerAggregateObject (objHandle,&IID_IAggregatedIface,pUnkAgg));
}
Error:
if (pUnk)
pUnk->lpVtbl->Release (pUnk);
if (pUnkAgg)
pUnkAgg->lpVtbl->Release (pUnkAgg);
return hr;
}
Parameters
| Input | ||
| Name | Type | Description |
| serverObjectHandle | CAServerObjHandle | The handle to an ActiveX object in your ActiveX server. |
| interfaceIdToAggregate | const IID * | The interface Id to aggregate in this object. |
| innerObjectIUnknown | IUnknown * | The IUnknown pointer of the object whose interface is being aggregated. |
Return Value
| Name | Type | Description | ||
| status | HRESULT | A value indicating whether an error occurred. Function failure is indicated by a negative error code. Error codes are defined in CVIversion\include\cviauto.h and <Program Files>\National Instruments\Shared\MSDTRedistributables\SDKHeaderFiles\8.1\winerror.h. The LabWindows/CVI ActiveX Library explicitly returns error codes. Other error codes in winerror.h are generated by the COM runtime and passed on to you by the ActiveX Library. You can use CA_GetAutomationErrorString to get the description of an error code or CA_DisplayErrorInfo to display the description of the error code.
The error codes defined in <Program Files>\National Instruments\Shared\MSDTRedistributables\SDKHeaderFiles\8.1\winerror.h are too numerous to display here. These error codes can be returned to your ActiveX clients. |
Additional Information
Library: ActiveX Library
Include file: cviauto.h
LabWindows/CVI compatibility: LabWindows/CVI 6.0 and later