INotifyingChangeApplierTarget.SaveChangeWithChangeUnits-Methode
Speichert, wenn in einer abgeleiteten Klasse überschrieben, eine Elementänderung, die Änderungen der Änderungseinheit enthält, im Elementspeicher.
Namespace: Microsoft.Synchronization
Assembly: Microsoft.Synchronization (in microsoft.synchronization.dll)
Syntax
'Declaration
Sub SaveChangeWithChangeUnits ( _
change As ItemChange, _
context As SaveChangeWithChangeUnitsContext _
)
'Usage
Dim instance As INotifyingChangeApplierTarget
Dim change As ItemChange
Dim context As SaveChangeWithChangeUnitsContext
instance.SaveChangeWithChangeUnits(change, context)
void SaveChangeWithChangeUnits (
ItemChange change,
SaveChangeWithChangeUnitsContext context
)
void SaveChangeWithChangeUnits (
ItemChange^ change,
SaveChangeWithChangeUnitsContext^ context
)
void SaveChangeWithChangeUnits (
ItemChange change,
SaveChangeWithChangeUnitsContext context
)
function SaveChangeWithChangeUnits (
change : ItemChange,
context : SaveChangeWithChangeUnitsContext
)
Parameter
- change
Die anzuwendende Elementänderung.
- context
Informationen über die anzuwendende Änderung.
Hinweise
Hinweise für Implementierer: Wenn es sich bei der in context enthaltenen Aktion um Create handelt, muss die Elementänderung atomar gespeichert werden. Dies bedeutet, dass entweder alle Änderungseinheiten erfolgreich gespeichert werden müssen oder die ganze Elementänderung verworfen werden muss. Wenn einige Änderungseinheiten gespeichert werden und andere nicht gespeichert werden können, kann dies zur Beschädigung von Daten führen. Wenn RecordRecoverableErrorForChangeUnit aufgerufen wird, und context ist Create, wird von RecordRecoverableErrorForChangeUnit die Ausnahme CreateFailuresMustBeForEntireItemException ausgelöst. Wenn die Synchronisierung während dieser Methode abgebrochen wird und der Anbieter einige der Änderungseinheiten übernommen hat, muss er für alle nicht übernommenen Änderungseinheiten RecordRecoverableErrorForChangeUnit aufrufen.
Beispiel
Im folgenden Beispiel wird die Behandlung einiger der häufigsten SaveChangeAction-Werte in der SaveChangeWithChangeUnits-Methode veranschaulicht.
Public Sub SaveChangeWithChangeUnits(ByVal change As ItemChange, ByVal context As SaveChangeWithChangeUnitsContext) Implements INotifyingChangeApplierTarget.SaveChangeWithChangeUnits
' Enumerate the change units received and apply them by using the specified action.
For Each cuChange As ChangeUnitChange In change.ChangeUnitChanges
Select Case context.GetActionForChangeUnit(cuChange)
Case SaveChangeAction.Create, SaveChangeAction.UpdateVersionAndData
If True Then
' Update the item store and metadata store for the specified change unit.
Try
Dim cuData As String = DirectCast(context.ChangeData, String())(cuChange.ChangeUnitId.GetByteId())
_ContactStore.UpdateContactFromSync(change, cuChange, cuData)
Catch ex As Exception
Dim errData As New RecoverableErrorData(ex)
context.RecordRecoverableErrorForChangeUnit(cuChange, errData)
End Try
Exit Select
End If
Case SaveChangeAction.UpdateVersionAndMergeData
If True Then
' Merge actions are not supported by this implementation.
Throw New NotImplementedException("UpdateVersionAndMergeData is not supported.")
End If
Case SaveChangeAction.UpdateVersionOnly
If True Then
' Update only the version of this change unit in the metadata store.
Try
_ContactStore.UpdateContactVersion(change.ItemId, cuChange.ChangeUnitId, cuChange.ChangeUnitVersion)
Catch ex As Exception
Dim errData As New RecoverableErrorData(ex)
context.RecordRecoverableErrorForChangeUnit(cuChange, errData)
End Try
Exit Select
End If
Case SaveChangeAction.DeleteAndRemoveTombstone, SaveChangeAction.DeleteAndStoreTombstone
If True Then
' Delete actions are handled in SaveItemChange, so throw an exception.
Throw New InvalidOperationException("SaveChangeWithChangeUnits received a delete action.")
End If
Case Else
If True Then
Throw New ArgumentOutOfRangeException("SaveChangeWithChangeUnits received an out-of-range action.")
End If
End Select
Next
' 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 SaveChangeWithChangeUnits(ItemChange change, SaveChangeWithChangeUnitsContext context)
{
// Enumerate the change units received and apply them by using the specified action.
foreach (ChangeUnitChange cuChange in change.ChangeUnitChanges)
{
switch (context.GetActionForChangeUnit(cuChange))
{
case SaveChangeAction.Create:
case SaveChangeAction.UpdateVersionAndData:
{
// Update the item store and metadata store for the specified change unit.
try
{
string cuData = ((string[])context.ChangeData)[cuChange.ChangeUnitId.GetByteId()];
_ContactStore.UpdateContactFromSync(change, cuChange, cuData);
}
catch (Exception ex)
{
RecoverableErrorData errData = new RecoverableErrorData(ex);
context.RecordRecoverableErrorForChangeUnit(cuChange, errData);
}
break;
}
case SaveChangeAction.UpdateVersionAndMergeData:
{
// Merge actions are not supported by this implementation.
throw new NotImplementedException("UpdateVersionAndMergeData is not supported.");
}
case SaveChangeAction.UpdateVersionOnly:
{
// Update only the version of this change unit in the metadata store.
try
{
_ContactStore.UpdateContactVersion(change.ItemId, cuChange.ChangeUnitId, cuChange.ChangeUnitVersion);
}
catch (Exception ex)
{
RecoverableErrorData errData = new RecoverableErrorData(ex);
context.RecordRecoverableErrorForChangeUnit(cuChange, errData);
}
break;
}
case SaveChangeAction.DeleteAndRemoveTombstone:
case SaveChangeAction.DeleteAndStoreTombstone:
{
// Delete actions are handled in SaveItemChange, so throw an exception.
throw new InvalidOperationException("SaveChangeWithChangeUnits received a delete action.");
}
default:
{
throw new ArgumentOutOfRangeException("SaveChangeWithChangeUnits received an out-of-range action.");
}
}
}
// 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);
}
Siehe auch
Verweis
INotifyingChangeApplierTarget-Schnittstelle
INotifyingChangeApplierTarget-Member
Microsoft.Synchronization-Namespace