SimpleSyncProvider.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)

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

public abstract void DeleteItem (
    ItemFieldDictionary keyAndExpectedVersion, 
    RecoverableErrorReportingContext recoverableErrorReportingContext, 
    /** @attribute OutAttribute() */ /** @ref */ boolean commitKnowledgeAfterThisItem
)

JScript does not support passing value-type arguments by reference.

參數

• keyAndExpectedVersion
  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
  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
  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

請參閱

參考

SimpleSyncProvider 類別
SimpleSyncProvider 成員
Microsoft.Synchronization.SimpleProviders 命名空間