INotifyingChangeApplierTarget.SaveItemChange 方法

在衍生類別中覆寫時，會將項目變更儲存至項目存放區。

命名空間: Microsoft.Synchronization
組件: Microsoft.Synchronization (在 microsoft.synchronization.dll)

語法

'宣告
Sub SaveItemChange ( _
    saveChangeAction As SaveChangeAction, _
    change As ItemChange, _
    context As SaveChangeContext _
)
'用途
Dim instance As INotifyingChangeApplierTarget
Dim saveChangeAction As SaveChangeAction
Dim change As ItemChange
Dim context As SaveChangeContext

instance.SaveItemChange(saveChangeAction, change, context)

void SaveItemChange (
    SaveChangeAction saveChangeAction,
    ItemChange change,
    SaveChangeContext context
)

void SaveItemChange (
    SaveChangeAction saveChangeAction, 
    ItemChange^ change, 
    SaveChangeContext^ context
)

void SaveItemChange (
    SaveChangeAction saveChangeAction, 
    ItemChange change, 
    SaveChangeContext context
)

function SaveItemChange (
    saveChangeAction : SaveChangeAction, 
    change : ItemChange, 
    context : SaveChangeContext
)

參數

• saveChangeAction
  要針對變更執行的動作。

• change
  要儲存的項目變更。

• context
  有關要套用之變更的資訊。

範例

下列範例將示範如何在 SaveItemChange 方法中處理一些最常見的 SaveChangeAction 值。

Public Sub SaveItemChange(ByVal saveChangeAction__1 As SaveChangeAction, ByVal change As ItemChange, ByVal context As SaveChangeContext) Implements INotifyingChangeApplierTarget.SaveItemChange
    Select Case saveChangeAction__1
        ' Update the item store and metadata store when an item is created or updated. 
        Case SaveChangeAction.Create, SaveChangeAction.UpdateVersionAndData
            If True Then
                Try
                    _itemStore.UpdateContactFromSync(change, DirectCast(context.ChangeData, String))
                Catch ex As Exception
                    Dim errData As New RecoverableErrorData(ex)
                    context.RecordRecoverableErrorForItem(errData)
                End Try
                Exit Select
            End If

            ' Update only the version of this item in the metadata store. 
        Case SaveChangeAction.UpdateVersionOnly
            If True Then
                Try
                    _itemStore.UpdateContactVersion(change.ItemId, change.ChangeVersion)
                Catch ex As Exception
                    Dim errData As New RecoverableErrorData(ex)
                    context.RecordRecoverableErrorForItem(errData)
                End Try
                Exit Select
            End If

            ' Delete the item from the item store and store a tombstone for it in the metadata store. 
        Case SaveChangeAction.DeleteAndStoreTombstone
            If True Then
                Try
                    _itemStore.DeleteContactFromSync(change.ItemId, change.ChangeVersion)
                Catch ex As Exception
                    Dim errData As New RecoverableErrorData(ex)
                    context.RecordRecoverableErrorForItem(errData)
                End Try

                Exit Select
            End If

            ' Neither merging of data nor removing tombstones is supported. 
        Case SaveChangeAction.UpdateVersionAndMergeData, SaveChangeAction.DeleteAndRemoveTombstone
            If True Then
                Throw New NotImplementedException()
            End If
        Case Else

            If True Then
                Throw New ArgumentOutOfRangeException()
            End If
    End Select

    ' Save the knowledge in the metadata store as each change is applied. Saving knowledge as each change is applied is 
    ' not required. It is more robust than saving the knowledge only after each change batch, because if synchronization is interrupted 
    ' before the end of a change batch, the knowledge will still reflect all of the changes applied. However, it is less efficient because 
    ' knowledge must be stored more frequently. 
    Dim knowledge As SyncKnowledge = Nothing
    Dim forgottenKnowledge As ForgottenKnowledge = Nothing
    context.GetUpdatedDestinationKnowledge(knowledge, forgottenKnowledge)
    _itemStore.ContactReplicaMetadata.SetKnowledge(knowledge)
End Sub

public void SaveItemChange(SaveChangeAction saveChangeAction, ItemChange change, SaveChangeContext context)
{
    switch (saveChangeAction)
    {
        // Update the item store and metadata store when an item is created or updated.
        case SaveChangeAction.Create:
        case SaveChangeAction.UpdateVersionAndData:
        {
            try
            {
                _itemStore.UpdateContactFromSync(change, (string)context.ChangeData);
            }
            catch (Exception ex)
            {
                RecoverableErrorData errData = new RecoverableErrorData(ex);
                context.RecordRecoverableErrorForItem(errData);
            }
            break;
        }

        // Update only the version of this item in the metadata store.
        case SaveChangeAction.UpdateVersionOnly:
        {
            try
            {
                _itemStore.UpdateContactVersion(change.ItemId, change.ChangeVersion);
            }
            catch (Exception ex)
            {
                RecoverableErrorData errData = new RecoverableErrorData(ex);
                context.RecordRecoverableErrorForItem(errData);
            }
            break;
        }

        // Delete the item from the item store and store a tombstone for it in the metadata store.
        case SaveChangeAction.DeleteAndStoreTombstone:
        {
            try
            {
                _itemStore.DeleteContactFromSync(change.ItemId, change.ChangeVersion);
            }
            catch (Exception ex)
            {
                RecoverableErrorData errData = new RecoverableErrorData(ex);
                context.RecordRecoverableErrorForItem(errData);
            }

            break;
        }

        // Neither merging of data nor removing tombstones is supported.
        case SaveChangeAction.UpdateVersionAndMergeData:
        case SaveChangeAction.DeleteAndRemoveTombstone:
        {
            throw new NotImplementedException();
        }

        default:
        {
            throw new ArgumentOutOfRangeException();
        }
    }

    // Save the knowledge in the metadata store as each change is applied. Saving knowledge as each change is applied is 
    // not required. It is more robust than saving the knowledge only after each change batch, because if synchronization is interrupted 
    // before the end of a change batch, the knowledge will still reflect all of the changes applied. However, it is less efficient because 
    // knowledge must be stored more frequently.
    SyncKnowledge knowledge;
    ForgottenKnowledge forgottenKnowledge;
    context.GetUpdatedDestinationKnowledge(out knowledge, out forgottenKnowledge);
    _itemStore.ContactReplicaMetadata.SetKnowledge(knowledge);
}

當提供者使用變更單位時，呼叫 SaveItemChange 方法只是為了處理刪除動作，如下列範例所示。

Public Sub SaveItemChange(ByVal saveChangeAction__1 As SaveChangeAction, ByVal change As ItemChange, ByVal context As SaveChangeContext) Implements INotifyingChangeApplierTarget.SaveItemChange
    ' This provider uses change units, so SaveChangeWithChangeUnits is called for all actions except delete actions.
    If SaveChangeAction.DeleteAndStoreTombstone = saveChangeAction__1 Then
        ' Delete the item from the item store and store a tombstone for it in the metadata store.
        Try
            _ContactStore.DeleteContactFromSync(change.ItemId, change.ChangeVersion)
        Catch ex As Exception
            Dim errData As New RecoverableErrorData(ex)
            context.RecordRecoverableErrorForItem(errData)
        End Try
    Else
        ' SaveChangeWithChangeUnits should be called for all actions other than delete actions.
        Throw New NotImplementedException("SaveItemChange only handles deletes!")
    End If

    ' Use the metadata storage service to save the knowledge as each change is applied. Saving knowledge as each change is applied is 
    ' not required. It is more robust than saving the knowledge only after each change batch, because if synchronization is interrupted 
    ' before the end of a change batch, the knowledge will still reflect all of the changes applied. However, it is less efficient because 
    ' knowledge must be stored more frequently.
    Dim updatedKnowledge As SyncKnowledge = Nothing
    Dim updatedForgottenKnowledge As ForgottenKnowledge = Nothing
    context.GetUpdatedDestinationKnowledge(updatedKnowledge, updatedForgottenKnowledge)
    _ContactStore.ContactReplicaMetadata.SetKnowledge(updatedKnowledge)
End Sub

public void SaveItemChange(SaveChangeAction saveChangeAction, ItemChange change, SaveChangeContext context)
{
    // This provider uses change units, so SaveChangeWithChangeUnits is called for all actions except delete actions.
    if (SaveChangeAction.DeleteAndStoreTombstone == saveChangeAction)
    {
        // Delete the item from the item store and store a tombstone for it in the metadata store.
        try
        {
            _ContactStore.DeleteContactFromSync(change.ItemId, change.ChangeVersion);
        }
        catch (Exception ex)
        {
            RecoverableErrorData errData = new RecoverableErrorData(ex);
            context.RecordRecoverableErrorForItem(errData);
        }
    }
    else 
    {
        // SaveChangeWithChangeUnits should be called for all actions other than delete actions.
        throw new NotImplementedException("SaveItemChange only handles deletes!");
    }

    // Use the metadata storage service to save the knowledge as each change is applied. Saving knowledge as each change is applied is 
    // not required. It is more robust than saving the knowledge only after each change batch, because if synchronization is interrupted 
    // before the end of a change batch, the knowledge will still reflect all of the changes applied. However, it is less efficient because 
    // knowledge must be stored more frequently.
    SyncKnowledge updatedKnowledge;
    ForgottenKnowledge updatedForgottenKnowledge;
    context.GetUpdatedDestinationKnowledge(out updatedKnowledge, out updatedForgottenKnowledge);
    _ContactStore.ContactReplicaMetadata.SetKnowledge(updatedKnowledge);
}

請參閱

參考

INotifyingChangeApplierTarget 介面
INotifyingChangeApplierTarget 成員
Microsoft.Synchronization 命名空間