Excel.RangePtr _NewEnum 的用法

Excel::RangePtr formulaCells = NULL;
IUnknownPtr pUnknown = formulaCells->_NewEnum;
IEnumVARIANTPtr pIEnum = NULL;
pUnknown->QueryInterface(__uuidof(IEnumVARIANT), (void**)&pIEnum);
VARIANT var;
while(true)
{
unsigned long numElements;
Excel::RangePtr pCell = NULL;
VariantInit(&var);
pIEnum->Next(1, &var, &numElements);
if (numElements == 0)
{
break;
}

var.pdispVal->QueryInterface(__uuidof(Excel::Range), (void**)&pCell);
}