Create a rectangular pattern of parts programatically

Here is an example. Remember that occurrences are "links to parts" inside an assembly:

bool CreateYArrayOfParts (CComPtr<ComponentOccurrences> pOccurrencesList, // The occurrences in the assembly

                          CComPtr<AssemblyComponentDefinition> pCctsAssemblyCompDef,   // def of the assembly

                          CComPtr<ComponentOccurrence> pObjOcc,

                          const double kDeltaYMm,

                          const UINT ikCount) 

{

    CComPtr<OccurrencePatterns> pOccPatterns ;

    pOccPatterns = pCctsAssemblyCompDef->GetOccurrencePatterns();

    if (pOccPatterns == nullptr) {

        gLogger.Printf(ekErrMsg, "GetOccurrencePatterns failed");

        return false;

    }

    CComPtr<TransientObjects> pTransientObjects = GetTransientObjectsPtr() ; 

    CComVariant varObjEnumerator;

    CComPtr<ObjectCollection> pObjectCollection;

    HRESULT hRes = pTransientObjects->CreateObjectCollection(varObjEnumerator, &pObjectCollection);

    if (FAILED(hRes)) {

        gLogger.Printf(ekErrMsg, "CreateObjectCollection failed");

        return false;

    }

    // Add the part which is the basis to the pattern...

    hRes = pObjectCollection->Add (pObjOcc) ;

    if (FAILED(hRes)) {

        gLogger.Printf(ekErrMsg, "Add to ObjectCollection failed");

        return false;

    }

    // Get hold of the y axis...

    CComPtr<WorkAxis> pYWorkAxis ;

    GetAsmWorkAxisByName (pYWorkAxis,L"Y Axis",pCctsAssemblyCompDef) ;

    if (FAILED(hRes)) {

        gLogger.Printf(ekErrMsg, "Could not get assembly y axis");

        return false;

    }

    pOccPatterns->AddRectangularPattern(pObjectCollection, 

                                        _variant_t((IDispatch *)pYWorkAxis),

                                        VARIANT_FALSE,

                                        CComVariant(kDeltaYMm/10.0), //ColumnOffset As Variant, 

                                        CComVariant(ikCount), // ColumnCount As Variant, 

                                        CComVariant(), // [RowEntity] As Variant, 

                                        VARIANT_TRUE, // [RowEntityNaturalDirection] As Boolean, 

                                        CComVariant(0.0),// [RowOffset] As Variant, 

                                        CComVariant(1)); //  [RowCount] As Variant)

    return (hRes == S_OK) ;

}

You could make it more general.

See also suppression of occurrences in a pattern.