HOW TO：從物件內容中斷物件的連結 (Entity Framework)
當您不再需要物件時，便可以從物件內容中斷物件的連結。 執行的方式是呼叫 Detach 方法。 這樣會減少使用的記憶體數量。
雖然中斷物件連結確實有好處，但是也應該要考量執行此作業所需的額外處理。 如需詳細資訊，請參閱附加及中斷連結物件。
本主題的範例是根據 Adventure Works Sales Model。 若要執行此範例中的程式碼，您必須已經將 AdventureWorks Sales Model 加入到專案中，並設定您的專案使用 Entity Framework。 若要這樣做，請完成 HOW TO：手動設定 Entity Framework 專案和 HOW TO：手動定義模型和對應檔 (Entity Framework) 中的程序。
範例
此範例會示範如何在應用程式不再需要 SalesOrderDetail 和 SalesOrderHeader 物件時，從 ObjectContext 中斷這些物件的連結。
' This method is called to detach SalesOrderHeader objects and
' related SalesOrderDetail objects from the supplied object
' context when no longer needed by the application.
' Once detached, the resources can be garbage collected.
Private Shared Sub DetachOrders(ByVal context As ObjectContext, ByVal order As SalesOrderHeader)
Try
' Detach each item from the collection.
While order.SalesOrderDetails.Count > 0
' Detach the first SalesOrderDetail in the collection.
context.Detach(order.SalesOrderDetails.First())
End While
' Detach the order.
context.Detach(order)
Catch ex As InvalidOperationException
Console.WriteLine(ex.ToString())
End Try
End Sub
// This method is called to detach SalesOrderHeader objects and
// related SalesOrderDetail objects from the supplied object
// context when no longer needed by the application.
// Once detached, the resources can be garbage collected.
private static void DetachOrders(ObjectContext context,
SalesOrderHeader order)
{
try
{
// Detach each item from the collection.
while (order.SalesOrderDetails.Count > 0)
{
// Detach the first SalesOrderDetail in the collection.
context.Detach(order.SalesOrderDetails.First());
}
// Detach the order.
context.Detach(order);
}
catch (InvalidOperationException ex)
{
Console.WriteLine(ex.ToString());
}
}