DeleteItem 方法
在衍生類別中覆寫時，由 Sync Framework 執行階段呼叫，以便從目的地存放區中刪除項目。
命名空間： Microsoft.Synchronization.SimpleProviders
組件： Microsoft.Synchronization.SimpleProviders (在 Microsoft.Synchronization.SimpleProviders.dll 中)
語法
'宣告
Public MustOverride Sub DeleteItem ( _
keyAndExpectedVersion As ItemFieldDictionary, _
recoverableErrorReportingContext As RecoverableErrorReportingContext, _
<OutAttribute> ByRef commitKnowledgeAfterThisItem As Boolean _
)
'用途
Dim instance As SimpleSyncProvider
Dim keyAndExpectedVersion As ItemFieldDictionary
Dim recoverableErrorReportingContext As RecoverableErrorReportingContext
Dim commitKnowledgeAfterThisItem As Boolean
instance.DeleteItem(keyAndExpectedVersion, _
recoverableErrorReportingContext, _
commitKnowledgeAfterThisItem)
public abstract void DeleteItem(
ItemFieldDictionary keyAndExpectedVersion,
RecoverableErrorReportingContext recoverableErrorReportingContext,
out bool commitKnowledgeAfterThisItem
)
public:
virtual void DeleteItem(
ItemFieldDictionary^ keyAndExpectedVersion,
RecoverableErrorReportingContext^ recoverableErrorReportingContext,
[OutAttribute] bool% commitKnowledgeAfterThisItem
) abstract
abstract DeleteItem :
keyAndExpectedVersion:ItemFieldDictionary *
recoverableErrorReportingContext:RecoverableErrorReportingContext *
commitKnowledgeAfterThisItem:bool byref -> unit
public abstract function DeleteItem(
keyAndExpectedVersion : ItemFieldDictionary,
recoverableErrorReportingContext : RecoverableErrorReportingContext,
commitKnowledgeAfterThisItem : boolean
)
參數
- keyAndExpectedVersion
型別：Microsoft.Synchronization.SimpleProviders. . :: . .ItemFieldDictionary
要刪除之項目的索引鍵和預期的版本屬性。提供者必須執行開放式並行存取檢查，以便驗證目的地的項目版本會對應至 keyAndExpectedVersion 中找到的值。如果這項檢查失敗，提供者應該使用 RecoverableErrorReportingContext 物件來報告可復原的錯誤。
- recoverableErrorReportingContext
型別：Microsoft.Synchronization.SimpleProviders. . :: . .RecoverableErrorReportingContext
用來報告嘗試刪除項目期間所發生之可復原錯誤的 RecoverableErrorReportingContext 物件。
- commitKnowledgeAfterThisItem
型別：System. . :: . .Boolean%
傳回 Sync Framework 執行階段是否應該在指定之項目的處理完成之後，將知識認可至中繼資料存放區。
備註
在 Sync Framework 偵測到來源中的變更並加以載入後，它必須將這些變更和對應的中繼資料變更套用到目的地複寫。目的地的中繼資料變更是由 Sync Framework 所處理，但是套用資料變更是存放區特定的動作，而且會藉由實作下列方法：DeleteItem、InsertItem 和 UpdateItem 來加以處理。
範例
下列程式碼範例示範這個方法的實作，此方法會將刪除套用到記憶體中的範例資料存放區。若要在完整應用程式的內容中檢視這段程式碼，請參閱 Sync Framework SDK 及 Code Gallery 中的 "Sync101 using Simple Sync Provider" 應用程式。
public override void DeleteItem(ItemFieldDictionary keyAndExpectedVersion,
RecoverableErrorReportingContext recoverableErrorReportingContext,
out bool commitKnowledgeAfterThisItem)
{
IDictionary<uint, ItemField> expectedFields = (IDictionary<uint, ItemField>)keyAndExpectedVersion;
ulong id = (ulong)expectedFields[CUSTOM_FIELD_ID].Value;
if (_store.Contains(id))
{
_store.DeleteItem(id);
}
else
{
// If the item to delete does not exist, record an error on this change and
// continue with the rest of the session.
recoverableErrorReportingContext.RecordRecoverableErrorForChange(new RecoverableErrorData(new Exception("Item not found in the store")));
}
commitKnowledgeAfterThisItem = false;
}
Public Overrides Sub DeleteItem(ByVal keyAndExpectedVersion As ItemFieldDictionary, ByVal recoverableErrorReportingContext As RecoverableErrorReportingContext, ByRef commitKnowledgeAfterThisItem As Boolean)
Dim expectedFields As IDictionary(Of UInteger, ItemField) = DirectCast(keyAndExpectedVersion, IDictionary(Of UInteger, ItemField))
Dim id As ULong = CULng(expectedFields(CUSTOM_FIELD_ID).Value)
If _store.Contains(id) Then
_store.DeleteItem(id)
Else
' If the item to delete does not exist, record an error on this change and
' continue with the rest of the session.
recoverableErrorReportingContext.RecordRecoverableErrorForChange(New RecoverableErrorData(New Exception("Item not found in the store")))
End If
commitKnowledgeAfterThisItem = False
End Sub