Export (0) Print
Expand All

ObjectContext.GetObjectByKey Method

Returns an object that has the specified entity key.

Namespace:  System.Data.Objects
Assembly:  System.Data.Entity (in System.Data.Entity.dll)

'Declaration
Public Function GetObjectByKey ( _
	key As EntityKey _
) As Object

Parameters

key
Type: System.Data.EntityKey

The key of the object to be found.

Return Value

Type: System.Object
An Object that is an instance of an entity type.

ExceptionCondition
ArgumentNullException

The key parameter is Nothing.

ObjectNotFoundException

The object is not found in either the ObjectStateManager or the data source.

GetObjectByKey tries to retrieve an object that has the specified EntityKey from the ObjectStateManager. If the object is currently not loaded into the object context, a query is executed in an attempt to return the object from the data source. For more information, see Object Queries (Entity Framework).

GetObjectByKey raises an ObjectNotFoundException when the object cannot be found. To avoid handling this exception, instead use the TryGetObjectByKey method.

This method will return objects in the Deleted state.

A temporary key cannot be used to return an object from the data source.

This example is based on the Adventure Works Sales Model. The example creates an EntityKey for an entity of the given type and then fetches an entity by key.

Using context As New AdventureWorksEntities()
    Try 
        ' Define the entity key values.  
        Dim entityKeyValues As IEnumerable(Of KeyValuePair(Of String, Object)) = _
            New KeyValuePair(Of String, Object)() {New KeyValuePair(Of String, Object)("SalesOrderID", 43680)}

        ' Create the key for a specific SalesOrderHeader object.  
        Dim key As New EntityKey("AdventureWorksEntities.SalesOrderHeaders", entityKeyValues)

        ' Get the object from the context or the persisted store by its key.  
        Dim order As SalesOrderHeader = DirectCast(context.GetObjectByKey(key), SalesOrderHeader)

        Console.WriteLine("SalesOrderID: {0} Order Number: {1}", order.SalesOrderID, order.SalesOrderNumber)
    Catch ex As ObjectNotFoundException
        Console.WriteLine(ex.ToString())
    End Try 
End Using

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5 SP1

.NET Framework Client Profile

Supported in: 4
Show:
© 2015 Microsoft