DataServiceContext.UpdateObject Method
Changes the state of the specified object in the DataServiceContext to Modified.
Namespace: System.Data.Services.Client
Assembly: Microsoft.Data.Services.Client (in Microsoft.Data.Services.Client.dll)
Syntax
'Declaration
Public Sub UpdateObject ( _
entity As Object _
)
'Usage
Dim instance As DataServiceContext
Dim entity As Object
instance.UpdateObject(entity)
public void UpdateObject(
Object entity
)
public:
void UpdateObject(
Object^ entity
)
member UpdateObject :
entity:Object -> unit
public function UpdateObject(
entity : Object
)
Parameters
- entity
Type: System.Object
The tracked entity to be assigned to the Modified state.
Exceptions
| Exception | Condition |
|---|---|
| ArgumentNullException | When entity is nulla null reference (Nothing in Visual Basic). |
| ArgumentException | When entity is in the Detached state. |
Examples
The following example retrieves and modifies an existing object and then calls the UpdateObject method on the DataServiceContext to mark the item in the context as updated. An HTTP MERGE message is sent to the data service when SaveChanges is called. This example uses the DataServiceContext generated by the Add Service Reference tool based on the Northwind data service, which is created when you complete the WCF Data Services?quickstart.
Dim customerId = "ALFKI"
' Create the DataServiceContext using the service URI.
Dim context = New NorthwindEntities(svcUri)
' Get a customer to modify using the supplied ID.
Dim customerToChange = (From customer In context.Customers _
Where customer.CustomerID = customerId _
Select customer).Single()
' Change some property values.
customerToChange.CompanyName = "Alfreds Futterkiste"
customerToChange.ContactName = "Maria Anders"
customerToChange.ContactTitle = "Sales Representative"
Try
' Mark the customer as updated.
context.UpdateObject(customerToChange)
' Send the update to the data service.
context.SaveChanges()
Catch ex As DataServiceRequestException
Throw New ApplicationException( _
"An error occurred when saving changes.", ex)
End Try
string customerId = "ALFKI";
// Create the DataServiceContext using the service URI.
NorthwindEntities context = new NorthwindEntities(svcUri);
// Get a customer to modify using the supplied ID.
var customerToChange = (from customer in context.Customers
where customer.CustomerID == customerId
select customer).Single();
// Change some property values.
customerToChange.CompanyName = "Alfreds Futterkiste";
customerToChange.ContactName = "Maria Anders";
customerToChange.ContactTitle = "Sales Representative";
try
{
// Mark the customer as updated.
context.UpdateObject(customerToChange);
// Send the update to the data service.
context.SaveChanges();
}
catch (DataServiceRequestException ex)
{
throw new ApplicationException(
"An error occurred when saving changes.", ex);
}