ISyncChangeBatchBase::GetChangeEnumerator

Obtiene un objeto IEnumSyncChanges que enumera los cambios de elemento de este lote de cambios.

HRESULT GetChangeEnumerator(
  IEnumSyncChanges ** ppEnum);

Parámetros

• ppEnum
  [out] Devuelve un enumerador que contiene los cambios de elemento de este lote de cambios.

Valor devuelto

• S_OK

• E_POINTER

• E_OUTOFMEMORY

Ejemplo

En el ejemplo siguiente se muestra la forma de enumerar los cambios en un lote de cambios remoto utilizando el objeto IEnumSyncChanges devuelto por GetChangeEnumerator. El ejemplo también muestra la forma de crear una lista de versiones locales que corresponde a los cambios enumerados.

STDMETHODIMP CMetadataMgr::GetItemBatchVersions(
    ISyncChangeBatch * pRemoteSyncChangeBatch,
    IEnumSyncChanges ** ppLocalVersionsEnum)
{
    HRESULT hr = E_UNEXPECTED;

    if (NULL == pRemoteSyncChangeBatch || NULL == ppLocalVersionsEnum)
    {
        hr = E_POINTER;
    }
    else
    {
        IProviderSyncServices* pProvSvc;
        hr = GetProviderSyncServices(&c_idParams, &pProvSvc);
        if (SUCCEEDED(hr))
        {
            IDestinationChangeVersionsBuilder* pDestChangeBuilder = NULL;
            hr = pProvSvc->CreateDestinationChangeVersionsBuilder(&pDestChangeBuilder);
            if (SUCCEEDED(hr))
            {
                IEnumSyncChanges* pRemoteEnum = NULL;
                hr = pRemoteSyncChangeBatch->GetChangeEnumerator(&pRemoteEnum);
                if (SUCCEEDED(hr))
                {
                    ULONG cFetched;

                    ISyncChange* pChange;
                    SYNC_GID gidItem;
                    DWORD cbID = sizeof(gidItem);
                    DWORD dwFlags;
                    SYNC_VERSION verCurrent;
                    SYNC_VERSION verCreation;
                    HRESULT hrEnum = S_OK;
                    while (S_OK == hrEnum && SUCCEEDED(hr))
                    {
                        pChange = NULL;
                        hrEnum = pRemoteEnum->Next(1, &pChange, &cFetched);
                        if (S_OK == hrEnum)
                        {
                            hr = pChange->GetRootItemId((BYTE*)&gidItem, &cbID);
                            if (SUCCEEDED(hr))
                            {
                                // Try to find the item in the local (destination) metadata.
                                IItemMetadata* pItem = NULL;
                                hr = FindItemMetadataByGlobalId((BYTE*)&gidItem, &pItem);
                                if (S_OK == hr)
                                {
                                    // S_OK means the item exists in our local store.
                                    // Extract its version and tombstone information.
                                    dwFlags = 0;

                                    BOOL fTombstone = FALSE;
                                    hr = pItem->GetIsDeleted(&fTombstone);
                                    if (SUCCEEDED(hr))
                                    {
                                        if (fTombstone)
                                        {
                                            dwFlags = SYNC_CHANGE_FLAG_DELETED;
                                        }
                                    }

                                    if (SUCCEEDED(hr))
                                    {
                                        hr = pItem->GetChangeVersion(&verCurrent);
                                        if (SUCCEEDED(hr))
                                        {
                                            hr = pItem->GetCreationVersion(&verCreation);                                            
                                        }
                                    }

                                    pItem->Release();
                                }
                                else if (S_FALSE == hr)
                                {
                                    // S_FALSE means this item does not exist in our local store.
                                    // Set versions to 0 and flag it as a new item.
                                    verCurrent.dwLastUpdatingReplicaKey = 0;
                                    verCurrent.ullTickCount = 0;
                                    verCreation.dwLastUpdatingReplicaKey = 0;
                                    verCreation.ullTickCount = 0;
                                    dwFlags = SYNC_CHANGE_FLAG_DOES_NOT_EXIST;
                                }

                                if (SUCCEEDED(hr))
                                {
                                    // Add the item to the batch of destination versions.
                                    GUID guidReplicaID = GUID_NULL;
                                    ULONG cbID = sizeof(guidReplicaID);
                                    hr = GetReplicaId((BYTE*)&guidReplicaID, &cbID);
                                    if (SUCCEEDED(hr))
                                    {
                                        hr = pDestChangeBuilder->AddItemMetadata((BYTE*)&guidReplicaID,
                                            (BYTE*)&gidItem, &verCurrent, &verCreation, dwFlags, NULL);
                                    }
                                }
                            }

                            pChange->Release();
                        }
                    }

                    if (FAILED(hrEnum))
                    {
                        hr = hrEnum;                    
                    }

                    pRemoteEnum->Release();                
                }

                if (SUCCEEDED(hr))
                {
                    hr = pDestChangeBuilder->GetChangeEnumerator(ppLocalVersionsEnum);               
                }

                pDestChangeBuilder->Release();
            }

            pProvSvc->Release();        
        }
    }

    return hr;
}

Vea también

Referencia

Interfaz ISyncChangeBatchBase