ObjectStateManager.GetObjectStateEntry Metodo

public:
 System::Data::Objects::ObjectStateEntry ^ GetObjectStateEntry(System::Data::EntityKey ^ key);

public System.Data.Objects.ObjectStateEntry GetObjectStateEntry (System.Data.EntityKey key);

member this.GetObjectStateEntry : System.Data.EntityKey -> System.Data.Objects.ObjectStateEntry

Public Function GetObjectStateEntry (key As EntityKey) As ObjectStateEntry

Parametri

Restituisce

Oggetto ObjectStateEntry corrispondente per l'oggetto EntityKey specificato.

Eccezioni

Esempio

In questo esempio viene ottenuto l'oggetto ObjectStateEntry per l'oggetto specificato EntityKey da ObjectStateManager. Ottiene quindi il valore corrente della proprietà, modifica il valore della SalesOrderHeader.PurchaseOrderNumber proprietà ed enumera l'insieme di proprietà modificate.

// Specify the order to update.
int orderId = 43680;

using (AdventureWorksEntities context =
    new AdventureWorksEntities())
{
    try
    {
        var order = (from o in context.SalesOrderHeaders
                     where o.SalesOrderID == orderId
                     select o).First();

        // Change the status of an existing order.
        order.Status = 1;

        // Delete the first item in the order.
        context.DeleteObject(order.SalesOrderDetails.First());

        // Create a new SalesOrderDetail object.
        // You can use the static CreateObjectName method (the Entity Framework
        // adds this method to the generated entity types) instead of the new operator:
        // SalesOrderDetail.CreateSalesOrderDetail(1, 0, 2, 750, 1, (decimal)2171.2942, 0, 0,
        //                                         Guid.NewGuid(), DateTime.Today));
        SalesOrderDetail detail = new SalesOrderDetail
        {
            SalesOrderID = 0,
            SalesOrderDetailID = 0,
            OrderQty = 2,
            ProductID = 750,
            SpecialOfferID = 1,
            UnitPrice = (decimal)2171.2942,
            UnitPriceDiscount = 0,
            LineTotal = 0,
            rowguid = Guid.NewGuid(),
            ModifiedDate = DateTime.Now
        };
        order.SalesOrderDetails.Add(detail);

        // Get the ObjectStateEntry for the order.
        ObjectStateEntry stateEntry =
            context.ObjectStateManager
            .GetObjectStateEntry(order);
        Console.WriteLine("State before SaveChanges() is called: {0}",
            stateEntry.State.ToString());

        // Save changes in the object context to the database.
        int changes = context.SaveChanges();

        Console.WriteLine("State after SaveChanges() is called: {0}",
            stateEntry.State.ToString());

        Console.WriteLine(changes.ToString() + " changes saved!");
        Console.WriteLine("Updated item for order ID: "
            + order.SalesOrderID.ToString());

        // Iterate through the collection of SalesOrderDetail items.
        foreach (SalesOrderDetail item in order.SalesOrderDetails)
        {
            Console.WriteLine("Item ID: "
                + item.SalesOrderDetailID.ToString() + "  Product: "
                + item.ProductID.ToString() + "  Quantity: "
                + item.OrderQty.ToString());
        }
    }
    catch (UpdateException ex)
    {
        Console.WriteLine(ex.ToString());
    }
}

Commenti

Utilizzare il TryGetObjectStateEntry(EntityKey, ObjectStateEntry) metodo per restituire un ObjectStateEntry oggetto senza dover gestire l'oggetto InvalidOperationException generato dal GetObjectStateEntry(EntityKey) metodo .

public:
 System::Data::Objects::ObjectStateEntry ^ GetObjectStateEntry(System::Object ^ entity);

public System.Data.Objects.ObjectStateEntry GetObjectStateEntry (object entity);

member this.GetObjectStateEntry : obj -> System.Data.Objects.ObjectStateEntry

Public Function GetObjectStateEntry (entity As Object) As ObjectStateEntry

Parametri

Restituisce

Oggetto ObjectStateEntry corrispondente per l'oggetto Object specificato.

Eccezioni

Commenti

Utilizzare il TryGetObjectStateEntry(Object, ObjectStateEntry) metodo per restituire un ObjectStateEntry oggetto senza dover gestire l'oggetto InvalidOperationException generato dal GetObjectStateEntry(Object) metodo .