lrc_CoObject_by_ref_from_variant

Extracting from Variants

Extracts a pointer to the IUnknown interface from a reference within a variant.

IUnknown* lrc_CoObject_by_ref_from_variant( VARIANT var );
var A variant.

The lrc_CoObject_by_ref_from_variant function extracts an IUnknown interface type pointer from a pointer to a variant.

Return Values

lrc Return Values

Parameterization

You cannot use standard parameterization for any arguments in this function.

Example

This example extracts the IUnknown interface IUnknown_0 from the variant reference var.

Copy code
//<span style="font-style: italic;">Build variant</span>
IUnknown * IUnknown_0 = 0;
IDispatch * IDispatch_0 = 0;

{
    GUID pClsid = lrc_GUID("ADODB.Recordset.2.1");
    IUnknown * pUnkOuter = (IUnknown*)NULL;
    unsigned long dwClsContext = lrc_ulong("7");
    GUID riid = IID_IUnknown;
    lrc_CoCreateInstance(&pClsid, pUnkOuter, dwClsContext, &riid, (void**)&IUnknown_0, CHECK_HRES);
}

{
    GUID riid = IID_IDispatch;
    lrc_IUnknown_QueryInterface(IUnknown_0, &riid, (void**)&IDispatch_0, CHECK_HRES);
}

//<span style="font-style: italic;">Extract IUnknown Interface</span>
VARIANT var = lrc_variant_CoObject_by_ref((IUnKnown*) IUnknown_0);
IUnknown_0= (IUnknown*)lrc_CoObject_by_ref_from_variant(var);